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Saturday, May 30, 2009

Arctic Sea Ice Trends over the Past 10 Years

Now that showed the Antarctic Sea Ice, it's time to check out the Arctic region.


The images below show the minimum sea ice extent during the month of September in 1999 and 2008 below it. They also show the Arctic sea ice maximum during the month of March in 1999 on the top right and 2009 below it.


Clearly, you can see that the greatest differences between the 1999/2000 and 2008/2009 season are during the sea ice minimum in September. You can also animate the images of all years since 1999 by clicking the play button on the Earth Observatory page.


The yellow outline on each image shows the median sea ice extent observed by satellite sensors in September and March from 1979 through 2000.


1999/2000

2008/2009

Since 1978, satellites have detected an overall decline in Arctic sea ice. The rate of decline steepened after the turn of the twenty-first century.


A key statement from the NASA article......


Cycles of natural variability such as the Arctic Oscillation are known to play a role in Arctic sea ice extent, but the sharp decline seen in this decade cannot be explained by natural variability alone. Natural variability and greenhouse gas emissions (and the resulting rise in global temperatures) likely worked together to melt greater amounts of Arctic sea ice.

------------

This time series is made from a combination of observations from the Special Sensor Microwave/Imagers (SSM/Is) flown on a series of Defense Meteorological Satellite Program missions and the Advanced Microwave Scanning Radiometer for EOS (AMSR-E), a Japanese-built sensor that flies on NASA’s Aqua satellite, according to the NASA Earth Observatory article.

Popular AGW Theory is Wrong, says Scientist

I read this piece about the problems of man-made global warming theory on Anthony Watts "Watts Up with That?" site. The piece, which is titled "Disproving The Anthropogenic Global Warming (AGW) Problem", is written by Dr. Leonard Weinstein (bio at the bottom of this page).


The opening paragraphs of Weinstein's paper are straight forward and well explained for the most part. Weinstein then lists six of the main predictions of man-made global warming models and then tries to show you why each one of those predictions is wrong.


Weinstein makes some strong points, but he also seems to be doing some cherry-picking as well. Let's take a look..........


1. While global atmospheric CO2 has indeed seen its steepest increase since 1940, it was already sharply increasing since the 1850's (industrial revolution). The atmospheric CO2 levels between 1940 and 1970 do not even compare (much lower) to what they are predicted to be from 2010 to 2100. Perhaps the modeling expects that these much higher levels of atmospheric CO2 in the future will be high enough to completely overwhelm natural climate cooling variables such as aerosols, la Nina, changes in the sun etc.....


Weinstein also states....It is also true that the present temperature trend is down and expected to continue downward for several more years before reversing again. What is his version of the present trend? This past year, past 5 years, 10 years? Also, some sources do predict a downward or stable trend for several years, while other sources disagree.


2. Weinstein states......The drop in temperature from 1940 to 1970 was claimed to have been caused by "global dimming" caused by aerosols made by human activity. This was stated as dominating the AGW effects at that time. This was supposed to have been overcome by activity initiated by the clean air act. In fact, the “global dimming” continued into the mid 1990’s and then only reduced slightly before increasing more (probably due to China and other countries increased activity). If the global dimming was not significantly reduced, why did the temperature increase from 1970 to just past 2000?


Weinstein seems to have forgotten about Mt. Pinatubo. Look at the chart below, courtesy of NASA, which plots global dimming aerosols. There was plenty of global dimming in the early 90s due to that volcano, but if you take out that volcano, then you can see there has been a steady decrease in global dimming aerosols from the 1980's through 2005.

3. Weinstein states......Claim 4 implies that the higher latitudes should heat up more than lower latitudes. In fact, the higher latitudes have warmed, but at a rate close to the rest of the world.


A rate close to the rest of the world? Not according to the RSS microwave satellite measurements. Check this out.........

His statement seems true in regards to the southern high latitudes since the 1980s, but it is clear that the northern high latitudes have warmed much more than the rest of the world since the mid 1990's. The far greater sea-surface area in the southern latitudes probably has a lot to do with the much more stable temperature anomaly trend down there, compared to the north.


4. Weinstein states.....In fact, Antarctica has overall cooled in the last 50 years except for the small tail that sticks out.


Not according to this research from Nature Journal back in Dec 2006, which shows a reconstruction of Antarctic temperature anomalies since 1957 over east and west Antarctica. According to the study.....the continent-wide average near-surface temperature trend is positive.


I am not saying that Weinstein is wrong. I am not sure. There is obviously some difference in opinion in regards to this 50-year trend.


5. Weinstein states.....Greenland and the arctic region are presently no warmer than they were in the late 1930’s, and are presently cooling!


The image below shows the temperature trends over the Arctic, including Greenland since 1981. Image courtesy NASA.

Where is that cooling he was talking about? I guess he meant parts of Siberia.


6. Weinstein states......it may be that the combination of the two (or more) volcanoes, along with Solar variability and variations in ocean currents (i.e., PDO) may explain the major causes of recent surface temperature rises to about 2002. In fact, the average Earth temperature stopped rising after 2002, and has been dropping for the last few years!


Mt. Pinatubo caused a period of cooling, not warming in the early 1990's. Weinstein also fails to mention the recent La Nina (late 2007/2008), which almost certainly had a role in the recent short term period of cooling. Also, depending on the source, the most recent period of global cooling was was less than two years in length and now appears to be creeping back up again in 2009, especially now that the most recent La Nina is officially dead.


7. Weinstein states....While some overall trends can be reasonably made based on looking at past historical trends, and some computational models can suggest some suggested trends due to specific forcing factors, nevertheless, the long term predicted result has not been shown to be valid.


Our overall assessment (IPCC)........
Coupled models have evolved and improved significantly since the SAR. In general, they provide credible simulations of climate, at least down to sub-continental scales and over temporal scales from seasonal to decadal. The varying sets of strengths and weaknesses that models display lead us to conclude that no single model can be considered "best" and it is important to utilize results from a range of coupled models. We consider coupled models, as a class, to be suitable tools to provide useful projections of future climates. Intergovernmental Panel on Climate Change


8. Weinstein states.....The overall effect of Antarctic and Greenland are now resulting in net gain (or at least near zero change) of ice, not loss.


ScienceDaily (Feb. 25, 2009) — The Greenland and Antarctica ice sheets are melting, but the amounts that will melt and the time it will take are still unknown, according to Richard Alley, Evan Pugh professor of geosciences, Penn State.


Seems like more controversy.

---------------
Bio courtesy of Energy Probe.


Leonard Weinstein received a B.S. in Physics in 1962 from Florida State University. He started work at NASA Langley Research Center in June 1962. While at Langley, Leonard obtained his Master and Doctor of Science degrees in Engineering from the George Washington University. He continued to work at NASA Langley until June 2007, ending as a Senior Research Scientist. Dr. Weinstein is presently a Senior Research Fellow at the National Institute of Aerospace.

Thursday, May 28, 2009

Monitoring Antarctic Sea Ice Since 1999

NASA's Earth Observatory shows us the maximum and minimum Antarctic sea ice extent since 1999.


1999/2000

2008/2009


The images show the maximum sea ice extent during each September going back ten years and the minimum extent, which occurs each February.


Since the start of the satellite record, total Antarctic sea ice has increased by about 1 percent per decade. Whether the small overall increase in sea ice extent is a sign of meaningful change in the Antarctic is uncertain because ice extents vary considerably from year to year and from sector to sector, according to the Earth Observatory report.


Sea ice extent in the Antarctic is greater than the Arctic's in the winter, but less than the Arctic in the summer due to large geographical differences.


You can push the play button below the images on the link for an animation of the max/min sea ice extents each year going back to 1999.

Burning Ice in Alaska?

I found this video segment from ABC News. A reporter begins the segment on the edge of the Bering Sea, which is located off the west coast of Alaska. The reporter then travels outside of Nome, Alaska and on to the frozen tundra, where he interviews one of the locals. According to the local man, the area experienced a stormier winter compared to normal.


According to the video, Alaska used to be a warm, tropical location millions of years ago, during periods of high atmospheric greenhouse gas concentration. Actually, much higher than what it is today.


The story then focuses on the potential carbon time bomb in Alaska, and that is the natural stores of CO2 and methane gas that were trapped millions of years ago in the permafrost. The permafrost is starting to melt and some scientists are worried that man's continued contribution of greenhouse gases to the atmosphere could cause the release of massive amounts of this CO2 and methane back into the atmosphere, leading to an abrupt and irreversible warming of the planet.


Oh yea, what about that burning ice? Just check out the video, and you will see what I mean.


You can watch the short video segment right here.

Monday, May 25, 2009

Glaciers that are Actually Growing

There are actually 230 glaciers in the western Himalayas, which includes Mount Everest and K2, that are defying global warming and are actually growing.


A view of the Mt. Everest region from the International Space Station.

"These are the biggest mid-latitude glaciers in the world," John Shroder of the University of Nebraska-Omaha said. "And all of them are either holding still, or advancing."


Shroder and a team of researchers looked at satellite imagery of the region's glaciers going back to 1960. According to the Discovery News report, a total of 87 glaciers in that region surged forward during that period of time.


It's a different story throughout much of the Tibetan Plateau, high-altitude glaciers are dwindling. The situation is potentially dire for the hundreds of millions of people living in China, India and throughout southeast Asia who depend on the glaciers for their water supply, according to the story.


Shroder suspects that the strong winds aloft (close to the jet stream) are carrying more moisture from the warmer Atlantic (not the case recently) and Mediterranean Sea on eastward into the western Himalayas.

Causes, Effects and Dangers of Global Warming

report by allie mendoza

What can we possibly do to help stop global warming? How do we solve a problem that seems too large to tackle and too complex to understand?

Earth Egg

by azrainman


We’ve all heard about global warming blaring from our TV sets and radios… we’ve seen countless web pages and news prints. Can we really continue to turn our heads away and pretend we don’t have enough evidence to take action?

By the time we get evidence that’s convincing enough for the global warming skeptics, will it be too late for the world as we know it?


By not taking action now, are we putting at risk the only planet we call home… for the off chance that global warming is NOT really going to cause massive destruction?


Are we willing to risk the environment that our children and future generations are going to inherit?


What Is Global Warming?

Global warming refers to the increase in the temperature of the Earth’s atmosphere. This results in the increase of our global average temperature.


It’s hard to understand why some people are still wondering if global warming is really occurring — the evidence provided is overwhelming.


It’s NOT reasonable to suggest that global warming is not occurring… just because we’ve had a couple of pretty cold winters lately. It’s NOT reasonable to compare “a couple of cold winters” to decades or centuries of OVERWHELMING EVIDENCE showing global warming.


For most people — especially most scientists — the only questions remaining are how much and how fast global warming will continue.


What Are the Main Causes of Global Warming?

The atmosphere has a natural supply of carbon dioxide (CO2) and other gases. These gases capture heat and create a warming effect on the surface of the Earth. This warming effect is similar to warming inside a greenhouse; so, it became known as the “greenhouse effect.”


Without the greenhouse effect, the Earth would not be warm enough for us to live on. It would just be a frozen wasteland.


Before the Industrial Revolution, the amount of natural emissions of CO2 and other greenhouse gases matched what could be removed. When the greenhouse gas emissions and removal were balanced, the greenhouse effect was good — it kept the Earth just warm enough to be habitable.


After the Industrial Revolution, increasingly larger amounts of greenhouse gas emissions were caused by humans. More and more fossil fuels — such as, oil, coal and natural gas — were burned to run factories, power plants, planes, cars and trucks. These human-caused emissions added significantly to the natural sources of greenhouse gases.


As a result, the greenhouse gases are building up beyond the Earth’s natural capacity to remove them. Since these atmospheric gases capture heat, this increase in gas emissions is causing an increase in global warming.


Global warming has increased the temperature of the Earth by about one degree Fahrenheit over the past century… with the last two decades heating up more intensely.


Why should an increase of one degree Fahrenheit matter to us?


If you consider that the difference in average global temperatures between modern times and the last ice age was only about 9 degrees Fahrenheit, it becomes clear that one degree is very significant.


This increase in global warming can cause a dramatic shift in our climate that can have devastating consequences… NOT just for the environment, but for our way of life.


What Are the Effects of Global Warming?

By burning more and more fossil fuels, human activities are adding CO2 much faster than the Earth’s natural capacity can remove.


CO2 is the main pollutant of global warming. Studies have shown that even small changes in CO2 levels lead to significant changes in average global temperature.


Due to human activities, CO2 emissions in the atmosphere have increased by 31% above pre-industrial levels — there is more CO2 in the atmosphere now than at any other time in the last 650,000 years.


Increasing the amount of CO2 and other greenhouse gases increases the greenhouse effect. This intensifies global warming.


If we don’t effectively reduce CO2 and other greenhouse gas pollution, it is predicted that global warming will increase the Earth’s average temperature by another 2.0 degrees Fahrenheit to 11.5 degrees Fahrenheit by 2100.


Even at the lower end of the predicted temperature, global warming and the resulting climate warming can lead to more intense storms, rising sea levels and more pronounced droughts.


At the high end of the predicted increase in temperature, global warming could lead to irreversible, catastrophic environmental consequences.


Read on to find out what can happen to your city, country or industry due to global warming…


What Are the Dangers of Global Warming?

The Earth has been showing signs and symptoms of global warming for quite some time. For many decades, scientists have been warning all of us about the dangers of global warming… but, few people paid much attention.The Earth is “talking” to us again… it’s message is loud and clear. If we continue to ignore it’s warning, we will suffer catastrophic environmental consequences on a scale previously unknown to our civilization.


Dangers Of Sea Level Rising

Currently, sea level is rising at 1/10 inch each year. Water expands when it is heated. So, with the global warming effect of CO2 already in our atmosphere, sea level can continue to rise for many centuries. To make matters worse, water melted from glaciers can also add to the sea level rising.


The impacts of rising sea level can include, flooding of cities, displacement of the people and loss of coastal ecosystems.


* If sea level rises 12 inches, 17%-43% of coastal wetlands in the United States could be eliminated… with more than half the loss in Louisiana. If sea level rises 24 inches, the United States could lose 10,000 square miles of dry land.


* Many of our cities face a severe risk of flooding. Thirteen out of fifteen of the largest cities in the world are on coastal plains. In California, parts of San Jose and Long Beach are three feet below sea level today. New Orleans is about eight feet below sea level.


* Bangladesh is projected to lose 17.5% of it’s land if sea level rises about 40 inches. With coastal flooding, tens of thousands of people are likely to be displaced. Plants and animals will also be lost.


* Many islands throughout the South Pacific and Indian Oceans as well as Maldives and French Polynesia will simply disappear under the rising seas. If the sea level rises 20 inches, 80% of the Majuro Atoll in the Pacific Marshall Islands will be under water.


Dangers of Infectious Diseases Spreading

Cold weather reduces the spread of infectious diseases by killing infectious organisms and their carriers, such as, mosquitoes. Global warming could increase the spread of malaria, dengue fever and yellow fever.


According to the World Health Organization, malaria has already spread to higher altitudes in places like the Columbian Andes, which is 7000 feet above sea level.


Dangers of Global Warming On Ecosystems

Millions of species worldwide could be driven to extinction due to global warming.

There are only about 3000-4500 Bengal tigers remaining in the wild. More tigers will be lost in Bangladesh as a result of global-warming related rise in sea levels.


With a 7-9 degree F change in mid-winter temperatures associated with the melting of sea ice pack on the western Antarctic Peninsula, shifting in penguin populations has been observed. Adelie penguins inhabit winter ice pack while Chinstrap penguins inhabit the open water. Chinstrap penguin populations increased by 400% in the last 25 years while Adelie penguins decreased by 22%.


Dangers of Disappearing Glaciers and Ice Packs

Almost all of the mountain glaciers on Earth have been shrinking and disappearing over the last century. With melting ocean ice cover, wildlife and humans will be seriously affected.


Walruses and polar bears have been observed to be thin and in poor condition due in part to the melting sea ice.


Deadly Heat Waves Are More Likely and More Frequent

In July 1995, 739 people in Chicago died when the temperature hit a record 106 degrees F. According to the Centers for Disease Control, access to air conditioning could have saved hundreds of lives… but, 49,000 homes lost power and air conditioning.


By the second day of the five-day heat wave, medical emergency rooms exceeded capacity. About 23 hospitals were closed to new patients. So, ambulances had to drive around town with nowhere to unload their patients. The morgue overflowed. Nine 48-foot meat trucks had to be brought in to store the dead bodies.


The world’s deadliest heat wave struck Europe in August 2003. A staggering 27,000 people in England, France, Germany and other parts of Europe died from the heat wave. More than 14,000 people died in France alone.


Survivors of the heat wave also suffered from dehydration, heat stroke, advanced stages of shock and fevers as well as irreversible brain damage.


Health spending was increased by $6.8 billion over five years by the French government. Due to the heat wave, medical costs soared.


Destructive Hurricanes Are More Likely and More Frequent

Hurricanes are fueled by warm ocean waters. Global warming, which is heating up ocean waters, is predicted to lead to more intense hurricanes.


According to a 2005 study done by Massachusetts Institute of Technology, the destructive potential of tropical storms has doubled over the past 30 years. According to a study done by Georgia Institute of Technology, the number of Category 4 and 5 hurricanes has doubled since the 1970s.


The destruction caused by Hurricane Katrina in 2005 shocked the world. Global warming is predicted to lead to more destructive hurricanes more frequently.


Global Warming Could Lead to Devastating Consequences For Our Economy

* If there isn’t enough snow or snow can not be created due to global warming, America’s $4.5 billion ski industry is dead.


* Global warming could lead to financial disasters for lobstermen. Studies have shown that temperatures ranging from 75 to 86 degrees F are lethal to lobsters.


In 1999, lobsters were dying in record numbers. By 2003, lobster populations were down 70% compared to 1998 levels.


* The taste and quality of wine depend on the soil and climate conditions in which the grapes are grown. Higher temperatures and less precipitation as well as more frequent and severe droughts due to global warming could have devastating effects on California’s $15 billion wine industry.


* And so on… and so on…


This post covered the causes, effects and dangers of global warming. The next post will cover how we can prevent, stop or slow global warming — even small changes can make a big difference.

Turkey Blamed for Looming Water Crisis

Fresh water conflict always makes me nervous. A country that is upstream must accommodate the needs of their dependents downstream. When the parties are barely talking it quickly becomes explosive. What is worse, the leadership is unable to divert public anger if the water flow becomes a problem. It is a classic cause of war.

I do not understand why the Turkish reserves are so low, or has the available water been diverted? A seventy percent decline seems extraordinary.

If rainfall is normal and Turkey has in fact diverted the majority of the flow to its own needs then there will be no reserve in the face of even a small drought. I can not imagine a more inflammatory scenario and the sooner they start talking the better. A regional drought would generate a huge impact and this sounds like a ticking time bomb, hopefully not to blamed on global warming.

Turkey blamed for looming crop 'disaster' in Iraq

by Staff WritersBaghdad (AFP) May 20, 2009

http://www.seeddaily.com/reports/Turkey_blamed_for_looming_crop_disaster_in_Iraq_999.html

Iraq faces an agricultural "disaster" this summer if Turkey continues to retain waters from the Tigris and Euphrates rivers which have sustained Iraqi agriculture for millennia, experts say.

The controversy over the sharing of the mighty rivers at the root of Iraq's ancient name of Mesopotamia -- meaning "between the rivers" in Greek -- is almost as old as the country itself.

But for Baghdad, the current shortage demands an urgent response from Turkey.

The reserves of all Iraqi dams at the beginning of May totalled 11 billion cubic metres (388 billion cubic feet) of water, compared to over 40 billion three years ago, although rain has not been below normal levels this winter.

The Euphrates is the most worrying situation.

Reserves at Haditha dam in the country's west, the first on the river, amounted to just 1.5 billion cubic metres on May 1, compared to eight billion two years ago.

"If the water level in the Euphrates continues to decrease, there will be a disaster in July because it will not be possible to irrigate crops," warned Aoun Thiab Abdullah, director of the National Centre for Water Resources.

"The drought will cause displacement," he said, noting that Iraqi agriculture depends on river water for 90 percent of its irrigation.

The negative impact on farming is already being felt in some provinces, including Najaf in the south that has banned its farmers from planting rice because it requires heavy irrigation.

"We will focus this year on the provision of drinking water and irrigation for other crops demanding less water," the director of the Centre for Water Resources in Najaf, Modhar al-Bakaa, told AFP at a water seminar.

The situation worsens as one moves down the Euphrates, according to Karim al-Yakubi, chairman of the agriculture and water committee in Iraq's parliament.

Yakubi said he fears an environmental disaster in the marshes of Nasiriyah farther south and notes that the lower water quantities increase the salinity of the river.

Iraqi experts say the problem is the many dams Turkey has built over the past 30 years to irrigate its agricultural lands in the southeast. These dams allow Turkey to regulate the flow of rivers according to its needs.

The flow speed of the Euphrates, which runs from Turkey through Syria, is currently only 230 cubic metres (8,100 cubic feet) per second, down from the 2000 level of 950 cubic metres per second.

Iraqi authorities have repeatedly sent letters to
Ankara requesting that Turkey allow the Euphrates to flow at 700 cubic metres a second, but apparently to little avail.

On the Tigris, the situation is not as serious but Turkey's gigantic Ilisu dam project which when finished will have a capacity greater than 10 billion cubic metres has Baghdad worried.

Turkish President Abdullah Gul promised in March to double the quota of water allocated to Iraq, during a historic visit to Baghdad, the first by a Turkish head of state in 33 years.

But the promise was not kept, according to Abdullah, who notes that the only bilateral treaty on water sharing came in 1946 when Iraq was hit by fears of flooding.

Under that agreement, Ankara had to inform its neighbour of any project likely to affect the flow of the rivers.

"Turkey no longer pays attention to us," said Abdullah.

To raise the profile of the water crisis, the Iraqi parliament last week passed a bill demanding that the issue of water now be included in all agreements with Ankara, parliament's Yakubi said.

Bidecadal Oscillations In Globally Averaged Temperature Trends

Basil Copeland and Anthony Watts
sun-earth-moon-520

Image from NASA GSFC


Many WUWT readers will remember that last year we presented evidence of what we thought was a “solar imprint” in globally averaged temperature trends. Not surprisingly, given the strong interest and passion in the subject of climate change and global warming, our results were greeted with both praise and scorn. Some problems were pointed out in our original assessment, and other possible interpretations of the data were suggested. Some WUWT readers have wondered whether we would ever follow up on this.


We have been quietly working on this, and having learned much since our initial effort, are as persuaded as ever that the basic premise of our original presentation remains valid. We have tried out some new techniques, and have posted some preliminary trials on WUWT in the past few months, here, and here.


However, questions remain. Since a lot of bright and capable people read WUWT, rather than wait until we thought we had all the answers, we have decided to present an update and let readers weigh in on where we are at with all of this. We have, in fact, drafted a paper that we might at some point submit for peer review, when we are more comfortable with some of the more speculative aspects of the matter. What follows is taken from that draft, with some modification for presentation here.


For those that prefer to read this in printed form, a PDF of this essay is available for download here


Introduction

Evidence of decadal and bidecadal variations in climate are common in nature. Classic examples of the latter include the 20 year oscillation in January temperature in the Eastern United States and Canada reported by Mock and Hibler [1], and the bidecadal rhythm of drought in the Western High Plains, Mitchell, Stockton, and Meko [2], and Cook, Meko, and Stockton [3]. Other examples include a bidecadal (and pentadecadal) oscillation in the Aleutian Low, Minobe [4]; rainfall and the levels of Lake Victoria, East Africa, Stager et al. [5]; and evidence from tree rings along the Russian Arctic, Raspopov, Dergachev, Kolstrom [6], and the Chilean coast, Rigozo et al. [7].


Evidence of decadal or bidecadal oscillations in temperature data, however, especially upon a global scale, has proven to be more elusive and controversial. Folland [8] found a spectral peak at 23 years in a 335 year record of central England temperatures, and Newell et al. [9] found a 21.8 year peak in marine air temperature. Brunetti, Mageuri, Nanni [10] have reported evidence of a bidecadal signal in Central European mean alpine temperatures. But the first to report bidecadal oscillations – of 21 and 16 years – in globally averaged temperature were Ghil and Vautard [11]. Their results were challenged by Eisner and Tsonis [12], but were later taken up and extended by Keeling and Whorf [13, 14].


No less unsettled is the issue of attribution. Currie [15], examining U.S. temperature records, reported spectral peaks of 10.4 and 18.8 years, attributing the first to the solar cycle, and the latter to the lunar nodal cycle. In the debate over the bidecadal drought cycle of the Western High Plains, Mitchell, Stockton, and Meko [2] concluded that the bidecadal signal was a solar phenomenon, not a lunar one. Bell [16, 17] and Stockton, Mitchell, Meko [18] attributed the bidecadal drought cycle to a combined solar and lunar influence, as did Cook, Meko, and Stockton [3]. Keeling and Whorf [13], working with globally averaged temperature data, reported strong spectral peaks at 9.3, 15.2, and 21.7 years. Eschewing a simpler combination of solar and lunar influences, they proposed a complex mechanism of lunar tidal influences to explain the evidence [14].


The past decade has seen only sporadic interest in the question of whether decadal and bidecadal variations in climate have a solar or lunar attribution, or some combination of the two. Cerveny and Shaffer [19] and Treloar [20] report evidence of tidal influences on the southern oscillation and sea surface temperatures; Yndestad [21, 22] and McKinnell and Crawford [23] attribute climate oscillations in the Arctic and North Pacific to the 18.6 year lunar nodal cycle. But interest in discerning an anthropogenic influence on climate has largely eclipsed the study of natural climate variability, at least on a global scale. There continue to be numerous reports of decadal or bidecadal oscillations in a variety of climate metrics on local and regional scales, variously attributed to solar and or lunar periods [3-7, 10, 19-27], but little has been done to advance the state of knowledge of lunar or solar periodic cycles on globally averaged temperature trends since the final decade of the 20th Century.


Besides the shift in interest to discerning an anthropogenic influence on global climate, the lack of agreement on any kind of basic physical mechanism for a solar role in climate oscillations, combined with the apparent lack of consistency in the relation between solar cycles and terrestrial temperature trends perhaps has made this an uninviting area of research. The difficulty of attributing temperature change to solar influence has been thoroughly surveyed by Hoyt and Schatten [28]. In particular, there are numerous reports of sign reversals in the relationship between temperature and solar activity in the early 20th century, particularly after 1920 [28, pp 115-117]. More recently, Georgieva, Kirov, and Bianchi [29] surveyed comprehensively the evidence for sign reversal in the relationship between solar and terrestrial temperatures, and suggested that these sign reversals are related to a long term secular solar cycle with solar hemispheric asymmetry driving the sign reversals. Specifically, they argue that there is a double Gleissberg cycle in which during one half of the cycle the Southern solar hemisphere is more active, while during the other half of the cycle the Northern solar hemisphere is more active. They argue that this solar hemispheric asymmetry is correlated with long term terrestrial climate variations in atmospheric circulation patterns, with zonal circulation patterns dominating in the 19th and early 20th century, and meridional circulation patterns dominating thereafter (see also [30] and [31]).


In our research, we pick up where Keeling and Whorf [13, 14] leave off, insofar as documenting decadal and bidecadal oscillations in globally averaged temperature trends is concerned, but revert to the explanation proposed by Bell [16] and others [3, 18], that these are likely the result of a combined lunisolar influence, and not simply the result of lunar nodal and tidal influences. We show that decadal and bidecadal oscillations in globally averaged temperature show patterns of alternating weak and strong warming rates, and that these underwent a phase change around 1920. Prior to that time, the lunar influence dominates, while after that time the solar influence dominates. While these show signs of being correlated with the broad secular variation in atmospheric circulation patterns over time, the persistent influence of the lunar nodal cycle, even when the solar cycle dominates the warming rate cycles, implicates oceanic influences on secular trends in terrestrial climate. Moreover, while analyzing the behavior of the secular solar cycle over the limited time frame for which we have reasonably reliable instrumental data for measuring globally averaged temperature should proceed with caution, if the patterns documented here persist, we may be on the cusp of a downward trend in the secular solar cycle in which solar activity will be lower than what has been experienced during the last four double sunspot cycles. These findings could influence our expectations for the future regarding climate change and the issue of anthropogenic versus natural variability in attributing climate change.


In our original presentation, we utilized Hodrick-Prescott smoothing to reveal decadal and bidecadal temperature oscillations in globally averaged temperature trends. While originally developed in the field of economics to separate business cycles from long term secular trends in economic growth, the technique is applicable to the time series analysis of temperature data in reverse, by filtering out short term climate oscillations, isolating longer term variations in temperature.


For the mathematically inclined, here is what the HP filter equation looks like, courtesy of the Mathworks

The Hodrick-Prescott filter separates a time series yt into a trend component Tt and a cyclical component Ct such that yt = Tt + Ct. It is equivalent to a cubic spline smoother, with the smoothed portion in Tt.

The objective function for the filter has the form

Figure0

where m is the number of samples and λ is the smoothing parameter. The programming problem is to minimize the objective over all T1, …, Tm. The first sum minimizes the difference between the time series and its trend component (which is its cyclical component). The second sum minimizes the second-order difference of the trend component (which is analogous to minimization of the second derivative of the trend component).

For those with an electrical engineering background, you could think of it much like a bandpass filter, which also has uses in meteorology:


Outside of electronics and signal processing, one example of the use of band-pass filters is in the atmospheric sciences. It is common to band-pass filter recent meteorological data with a period range of, for example, 3 to 10 days, so that only cyclones remain as fluctuations in the data fields.


(Note: For those that wish to try out the HP filter on data themselves, a freeware Excel plugin exists for it which you can download here)


When applied to globally averaged temperature, the HP filter works to extract the longer term trend from variations in temperature that are of short term duration. It is somewhat like a filter that filters out “noise,” but in this case the short term cyclical variations in the data are not noise, but are themselves oscillations of a shorter term that may have a basis in physical processes.


This approach reveals alternating cycles of weak and strong warming rates with decadal and bidecadal frequency. We confirm the validity of the technique using a continuous wavelet transform. Then, using MTM spectrum analysis, we analyze further the frequency of these oscillations in global temperature data. Using sinusoidal model analysis we show that the frequencies obtained using HP smoothing are equivalent to what are obtained using MTM spectrum analysis. In other words, the HP smoothing technique is simply another way of extracting the same spectral density information obtained using more conventional spectrum analysis, while leaving it in the time domain. This allows us to compare the secular pattern of temperature cycles with solar and lunar maxima, yielding results that are not obvious from spectral analysis alone.


Using the Hodrick-Prescott Filter to Reveal Oscillations in Globally Averaged Temperature

We use the open source econometric regression software gretl (GNU Regression, Econometrics, and Time Series) [34] to derive an HP filtered time series for the HadCRUT3 Monthly Global Temperature Anomaly, 1850:01 through 2008:11 [35].

Figure1

Figure1 - click for larger image

Figure 1 is representative output in gretl for a series filtered with HP smoothing (λ of 129,000). In the top panel is the original series (in gray), with the resulting smoothed trend (in red). In the bottom panel is the cyclical component. In econometric analysis, attention usually focuses on the cyclical component. Our focus, though, is on the trend component in the upper panel, and in particular the first differences of the trend component. The first differences of a trend indicate rate of change.


By taking the first differences of the smoothed trend in Figure 1, we obtain the series (in blue) shown in Figure 2, plotted against the background of the original data (gray), and the smoothed trend (red).

Figure 2 - click for larger image

Figure 2 - click for larger image

What does this reveal? At first glance, we see an alternating pattern of decadal and bidecadal oscillations in the rate of warming, with a curious exception circa 1920-1930. We will return to this later. Concentrating for now on the general pattern, these oscillations in the rate of warming are representations, in the time domain, of spectral frequencies in the temperature data, with high frequency oscillations filtered out by the HP smoothing.


As evidence of this, Figure 3 presents the result of two Morelet continuous wavelet transforms, the first (in the upper panel) of the unfiltered HadCRUT3 monthly time series, and the second (in the lower panel) of results obtained with HP smoothing.

Figure3

The wavelet transforms below a frequency of ~7 years (26.4 ≈ 84 months) are visually identical; the HP filter is simply acting as a low pass filter, filtering out oscillations with frequencies above ~7 years, while preserving the decadal and bidecadal oscillations of interest here. In the next section, we investigate these oscillations in further detail, supplementing our results from HP filtering with MTM spectrum analysis, and a sinusoidal model fit.


Frequency Analysis

Figure 4 is an MTM spectrum analysis of the unfiltered HadCRUT3 monthly global temperature analysis.

Figure 4 - click for larger image

Figure 4 - click for larger image

A feature of MTM spectrum analysis is that it distinguishes signals that are described as “harmonic” from those that are merely “quasi-oscillatory.” In MTM spectrum analysis a harmonic is a more clearly repeatable signal that passes a stronger statistical test of its repeatability. Quasi-oscillatory signals are statistically significant, in the sense of rising above the background noise level, but are not as consistently repeating as the harmonic signals.


The distinction between harmonic and quasi-oscillatory signals is well illustrated in Figure 4 by the two cycles that interest us the most – a “quasi-oscillatory” cycle with a peak at 8.98 years, and a “harmonic” signal centered at 21.33 years. Also shown are a harmonic, and a quasi-oscillatory cycle, of shorter frequencies, possibly ENSO related. The harmonic at 21.33 years in Figure 4 encompasses a range from 18.96 to 24.38 years, and the quasi-oscillatory signal that peaks at 8.93 years has sidebands above the 99% significance level that range from 8.53 to 10.04 years. These signals are consistent with spectra identified by Keeling and Whorf [13,14].


Figure 5 is an MTM spectrum analysis of the HP smoothed first differences.

figure5

Figure5 - click for larger image

The basic shape of the spectrum is unchanged, but it is now well above the background noise level because of the HP filtering. Attention is drawn in Figure 5 to four oscillatory modes or cycles because they correspond to the four strongest cycles derived from using the PAST (PAleontological STatistics) software [36] to fit a sinusoidal model to the HP smoothed first differences.


Shown in Figure 6, the sinusoidal fit results in periods of 20.68, 9.22, 15.07 and 54.56 years, in that order of significance. These periodicities fall within the ranges of the spectra obtained using MTM spectrum analysis, and yield a sinusoidal model with an R2 of 0.60.

Figure6

Figure6 - click for larger image


Discussion

The first differences of the HP smoothed temperature series, shown in Figure 2 and Figure 6, show a pattern of alternating decadal and bidecadal oscillations in globally averaged temperature. From the sinusoidal model fit, these cycles have average frequencies of 20.68 and 9.22 years, results that are consistent with the MTM spectrum analysis, and with spectra in the results published by Keeling and Whorf [13, 14]. But to what can we attribute these persistent periodicities?


A bidecadal frequency of 20.68 years is too short to be attributed solely to the double sunspot cycle, and too long to be attributed solely to the 18.6 year lunar nodal cycle. There is indeed evidence of a spectral peak at ~15 years, which Keeling and Whorf combined with their evidence of a 21.7 year cycle to argue for attributing the oscillations entirely to the 18.6 year lunar nodal cycle.


But our evidence indicates that the ~15 year spectrum is much weaker, is not harmonic, and probably derives from the anomalous behavior of the spectra circa 1920-1930, something Keeling and Whorf could not appreciate with evidence only from the frequency domain. Especially in light of the evidence presented below, and because the bidecadal signal is harmonic, and readily discernible in the time domain representation of Figure 2 and Figure 6, we believe that a better attribution is the beat cycle explanation proposed by Bell [16], i.e. a cycle representing the combined influence of the 22 year double sunspot cycle and the 18.6 year lunar nodal cycle.


As for the decadal signal of 9.22 years, this is too short to be likely attributable to the 11 year solar cycle, but is very close to half the 18.6 year lunar nodal cycle, and thus may well be attributable to the lunar nodal cycle. Together, the pattern of alternating weak and strong warming cycles shown in Figure 2 and Figure 6 suggest a complex pattern of interaction between the double sunspot cycle and the lunar nodal cycle.


This complex pattern of interaction between the double sunspot cycle and lunar nodal maxima in relation to the alternating pattern of decadal and bidecadal warming rates is demonstrated further in Figure 6 with indicia plotted to indicate solar and lunar maxima. Since circa 1920, the strong warming rate cycles have tended to correlate with solar maxima associated with odd numbered solar cycles, and the weak warming rate cycles with lunar maxima.


Prior to 1920, the strong warming rate cycles tend to correlate with the lunar nodal cycle, with the weak warming rate cycles associated with even numbered solar cycles. The sinusoidal model fit begins to break down prior to 1870. Whether this is a reflection of the poorer quality of data prior to 1880, or indications of an earlier phase shift, we cannot say, though the timing would be roughly correct for the latter. But the anomalous pattern circa 1920, when viewed against the shift from strong warming rate cycles dominated by the lunar nodal cycle, to strong warming rate cycles dominated by the double sunspot cycle, has the appearance of a disturbance associated with what clearly seems to be a phase shift


These results agree with the evidence mustered by Hoyt and Schatten [28] and Georgieva, Kirov, and Bianchi [29] for a phase shift circa 1920 in the relationship between solar activity and terrestrial temperatures. However, we can suggest, here, that the supposed negative correlation between solar activity and terrestrial temperatures prior to 1920 rests on a misconstrued understanding of the data. As can be seen in Figure 6, the relationship between the change in the warming rate and solar activity is still positive, i.e. the warming rate is peaking near the peaks of solar cycles 10, 12, and 14, but at a much reduced level, indicative of the lower level of solar activity during the period. Indeed, for much of solar cycle 12, and all of solar cycle 14, the “warming” rate is negative, but the change in the warming rate is still following the level of solar activity, becoming less negative as solar activity increases, and more negative as solar activity decreases. Still, there is a strong suggestion in Figure 6 of a phase shift circa 1920 in which the relationship between solar activity and terrestrial temperatures changes dramatically before and after the shift. Before the shift, the lunar period dominates, and the solar period is much weaker. After the shift, the solar period dominates, and the lunar period becomes subordinate.


Speculating

To this point, we believe that we are on relatively solid ground in describing what the data show, and the likelihood of a lunisolar influence on global temperatures on decadal and bidecadal timescales. What follows now is more speculative. To what can we attribute the apparent phase shift circa 1920, evident not just in our findings, but as reported by Hoyt and Schatten [28] and Georgieva, Kirov, and Bianchi [29]? While the period of data is too short to do more than speculate, the periods before and after the phase shift appear to be roughly equivalent in length to the Gleissberg cycle.


Since 1920, we’ve had four double sunspot cycles with strong warming rates ending in odd numbered cycles. Prior to 1920, while the results are less certain at the beginning of the data period, there is a reasonable interpretation of the data in which we see four bidecadal periods dominated by the influence of the lunar cycle. These differences may be attributable to the broad swings in atmospheric “circulation epochs” discussed by Georgeiva, et al. [30], characterized either predominantly by zonal circulation, or meridional circulation. With respect to the period of time shown in Figure 6, zonal circulation prevailed prior to 1920, and since then meridional circulation has dominated. These “circulation epochs” may have persistent influence on the relative roles of solar and lunar influence in warming rate cycles.


While the role of variation in solar irradiation over the length of a solar cycle on the broad secular rise in global temperature is disputed, we are presenting here evidence primarily of a more subtle repeated oscillation in the rate of change in temperature, not its absolute level. As shown in Figure 2 and Figure 6, the rate of change oscillates between bounded positive and negative values (with the exception circa 1920 duly noted). Variations in solar irradiance over the course of the solar cycle are a reasonable candidate for the source of this variation in warming rate cycle. As WUWT’s “resident solar physicist”, Leif Svalgaard, has pointed out, variations in TSI over a normal solar cycle can only account for about 0.07°C of total variation over the course of a solar cycle. The range of change in warming rates shown in Figure 2 and Figure 6 are at most only about one-tenth of this, or about ~0.006°C to ~0.008°C. If anything, we should be curious why the variation is so small. We attribute this to the averaging of regional and hemispheric variations in the globally averaged data. On a regional basis, analysis [not presented here] shows much larger variation, but still within the range of 0.07°C that might plausibly be attributed to the variation in TSI over the course of a solar cycle.


So variations in solar irradiance over the course of the solar cycle are a reasonable candidate for the source of this variation in warming rate cycle. At the same time, the lunar nodal cycle may be further modulating this natural cycle in the rate of change in global temperatures. As to the degree of modulation, that may be influenced by atmospheric circulation patterns. With zonal circulation, the solar influence is moderated and the lunar influence dominates the modulation of the warming rate cycles. With meridional circulation, the solar influence is stronger, and the warming rate cycles are dominated by the solar influence.


At this writing, we are in the transition from solar cycle 23 to 24, a transition that has taken longer than expected, and longer than the transitions typical of solar cycles 16 through 23. Indeed, the transition is more typical of the transitions of solar cycles 10 through 15. If the patterns observed in Figure 6 are not happenstance, we may be seeing an end to the strong solar activity of solar cycles 16-23, and a reversion to the weaker levels of activity associated with solar cycles 10-15. If that occurs, then we should see a breakdown in the correlation between warming rate cycles and solar cycles at bidecadal frequencies, and a reversion to a dominant correlation between temperature oscillations and the lunar nodal cycle.


Interestingly, there was a lunar nodal maximum in 2006 not closely associated with the timing of decadal or bidecadal oscillations in globally averaged temperature. This could be an indication of a breakdown in the pattern similar to what we see in the 1920’s, i.e. the noise associated with a phase shift in the weaker warming rate cycles will occur at times of the solar maximum, and the stronger warming rate cycles will occur at times of lunar nodal maximum.


Repeating, there appear to be parallels between our findings and the argument of Georgieva et al. [29] of a relationship between terrestrial climate and solar hemispheric asymmetry on the scale of a double Gleissberg cycle. Solar cycles 16-23, associated as we have seen with increased solar activity, and strong correlations with the strong terrestrial warming rate cycles of bidecadal frequency, represent 8 solar cycles, a period of time associated with a Gleissberg cycle.


While the existence of Gleissberg length cycles is hardly challenged, their exact length and timing is subject to a debate we will not entertain here at any length. Javariah [37] on the basis of the disputed 179 year cycle of Jose [38] believes that a descending phase of a Gleissberg cycle is already underway, and will end with the end of a double Hale cycle comprising solar cycles 22-25.


While it is true that solar activity, as measured by SSN, is already on the decline, we would include the double Hale cycle 20-23 in the recent peak of solar activity, and not necessarily expect to see the bottom of the current decline in solar activity that quickly.


The issue here can perhaps be framed with respect to Figure 7 below:

figure7

Figure7 - click for larger image

Assuming we are on the cusp of a downward trend in solar activity that began circa 1990 according to Javariah, and will decline, say, to a level comparable to the trough seen in the early 1900’s, will it be a sharp decline, like that seen at the beginning of the 19th Century, or a more moderate decline like that seen at the beginning of the 20th Century? A naïve extrapolation might be to replicate the more gradual decline seen during the latter half of the 19th Century, suggesting a gradual decline in solar activity through solar cycle 31, i.e. for most of the 21st Century. And based on the prospect of a phase shift in the pattern of decadal and bidecadal warming rate cycles, the bidecadal cycle would come to be dominated by the influence of the lunar nodal cycle, and the influence of the solar cycle would be diminished, leading at least to a reduction in the rate of global warming, if not an era of global cooling.


This is a prospect worthy of more investigation.


Finally, while we readily concede that multidecadal projections are at best little more than gross speculation, in Figure 6 we have carried the sinusoidal model fit out to 2030, and in Figure 8 we use the sinusoidal model of rate changes to project temperature

Figure 8 - click for larger image

Figure 8 - click for larger image

anomalies through 2030. Assuming a simple projection of the sinusoidal model of rate changes persists through 2030, there would be little or no significant change in global temperature anomalies for the next two decades.


Looking carefully at the sinusoidal model, what we are seeing projected for 2010-2020 are a return to conditions similar to what the model shows for circa 1850-1860, with the period 1853-2020 representing a complete composite cycle of the four combined periods of oscillation. That is, 1853 is the first point at which the sinusoidal model is crossing the x-axis, and at 2020 the model again crossing the x-axis and beginning to repeat a ~167 year cycle. In terms of solar cycle history, that corresponds to a return to conditions similar to solar cycles 10-15, with another phase shift reversing the phase shift of ~1920. If these broad, long term secular swings in solar activity and global atmospheric conditions and temperature anomalies are not random, but reflect solar-terrestrial dynamics that play out over multidecadal and even centennial time-scales, then the early 21st Century may yield a respite from the global warming of the late 20th Century.


Conclusion

There is substantial and statistically significant evidence for decadal and bidecadal oscillations in globally averaged temperature trends. Sinusoidal model analysis of the first differences of the HP smoothed HadCRUT3 time series reveals strong periodicities at 248.2 and 110.7 months, periodicities confirmed as well with MTM spectrum analysis.


Analyzing these periodicities in the time domain with the first differences of the HP smoothed HadCRUT3 time series reveals a pattern of correlation between strong warming rate cycles and the double sunspot cycle for the past four double sunspot cycles. Prior to that, with a phase shift circa 1920, the strong warming rate cycles were dominated by the timing of the lunar nodal cycle.


We suggest that this reversal may be related to a weaker epoch of solar activity prior to 1920, and that we may on the cusp of another phase shift associated with a resumption of such weakened solar activity.


If so, this may result in a reduction in the rate of global warming, and possibly a period of global cooling, further complicating the effort to attribute recent global warming to anthropogenic sources.

Limitations on Anthropogenic Global Warming

reposted from The Air Vent
It is not obvious what the ideal temperature and CO2 level should be for mankind. We tend to assume that the average of whatever has occurred in the recent past is the ideal level, since we have adjusted to that level, and changes from that level can cause disruptions in living conditions and activities. Significant temperature and CO2 increases in recent years have raised the issue of whether these were possibly related and were due to human activity, and whether this is a potentially significant problem.


Earth’s temperature has only been directly measured at enough locations to give a reasonably accurate global average for about the last 150 years, with the greatest accuracy (from satellites) only going back about 30 years. The “reliable” CO2 background level has only been directly continuously measured at one location (Mauna Loa) for about 50 years, and at a much larger number of locations for about 30 years. Some other direct and indirect CO2 measurements were made prior to 50 years ago, and the measurements thought to be most reliable were used to extend the CO2 curve back to 1850.


Figure 1 is a commonly used figure to show smoothed global variations of the temperature and CO2 concentration data from 1850 through 2000 AD. This data indicates the Earth’s surface has warmed about 0.7OC (1.3 OF) and the atmospheric CO2 appears to have increased by over 30%. These two pieces of information are the basis for the present “Anthropogenic Global Warming issue”.

Figure 1. Variation of global average temperature and CO2 concentration over last 150 years


(Sources for temperature and CO2: http://www.grida.no/climate/ipcc_tar/wg1/519.htm )


A more recent version of the temperature anomaly for the period 1850 through 2008 is shown in figure 2. The data, from http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/ is also shown as a smoothed yearly variation, including range of uncertainty.

Figure 2. Yearly anomaly of global temperature variation from 1850 through 2008


This newer data somewhat modifies the conclusion that had been inferred from the more limited temperature curve from figure 1, where the belief (supported by the IPCC) was that the increasing CO2 was the main cause of the increasing temperature. The temperature trend has peaked about 2002 and then rolls over and starts trending downward rather than continuing to rise as predicted. This apparent reversal contradicts the predicted trends in the IPCC models. While the downward trend has occurred only a over a few years, the entire period used to justify the “Anthropogenic Global Warming issue” is not much longer (1970-2000), and the 1970 level is significantly below the 1941 level!


There are several indirect ways to determine temperature variations that extend the record back much further than 150 years. These include (but are not limited to) historical written records, information from tree rings, glacier ice cores, sediment deposits, and borehole temperatures. The accuracy and distribution of these methods for the global average is thought to be fairly good to about 400 years ago. However, the limited number of locations for these records as we go farther back in time tends to decrease the absolute levels of confidence of the indirect records for an average global temperature prior to 400 years ago. The trend can be extended back about another thousand years or so, but with decreasing confidence in the global average the farther back you go. A few local sources showing temporal variations can extend the record back much farther in time, but these are not global averages.


Tree ring data can extend the temperature trend record back several thousand years, but do not give reliable absolute levels due to sensitivity to parameters such as being restricted to land, and having unknown rainfall, Solar insolation, local CO2 level, etc. They also do not show winter or nighttime data, and are thus not truly average temperature indicators. Borehole data is limited in temporal resolution, and only goes back reliably a few hundred years at most. In the end, glacier ice core data at a limited few locations, and sea floor sediment cores, are the most reliable and longest period data sources for temperature. The CO2 variations are also claimed to be obtainable from glacier ice cores, going back hundreds of thousands of years, but a question of the validity of that claim is discussed in more detail later in this paper. A combination of data from several techniques indicate that the average surface temperature was relatively warm about 1,000 years ago, and this period was called the “Medieval Climate Optimum”. This changed about 1,200 AD or so into a prolonged colder period called the “Little Ice Age”, which lasted until about 1850. The temperature variations were not uniformly distributed and it is not clear if the “Little Ice Age” extended to the southern hemisphere. The accurate average level of the temperature that occurred during the “Medieval Climate Optimum” and the speed at which it changed were not able to be reliably determined, due to the limited number of data points, and increased uncertainty in accuracy of many of the sources that far back in time.


The AGW proponents claim that the magnitude and level of the present global temperature, and the speed in which it increased, is unusually extreme and cannot be accounted for by natural variations. They claim the observed temperature increase is being caused by human activities such as the burning of fossil fuels, deforestation, and manufacture of cement. The observed recent increase in CO2 (and also Methane) is thought to have increased the greenhouse effect of atmospheric gases to trap more radiated heat and thus raise the surface temperature. In order to examine the AGW claims, temperature data is shown in figure 3 from three widely separated sources. The data covers the last three thousand years for a representative Greenland ice core and Sargasso Sea sediment core, and the last two thousand years for an Antarctic ice core (all data taken from web sources, including NOAA).


The ice core data was taken from locations on glaciers that had minimal lateral substrate movement, and did not melt on the surface in the summer. The yearly snow variation was sufficient to accurately identify the year of the layers in the compacted solid ice core. Oxygen isotope ratios were used to determine the temperature, and the data shows the variation in temperature relative to the year 2000. The Sargasso Sea sediment core temperature data were obtained from the Oxygen isotope ratio of the surface-dwelling planktonic foraminifera, and shows the sea surface temperature for the last 3,000 years. Conclusions from these curves are:

  1. The temperature varied several times over the period by 1.5 OC to 2OC for all three curves
  2. Temperature variations occurred fairly rapidly, with typical time scales of 50 to 200 years
  3. The rise rate over the last 150 years is not unusual compared to other rise rates
  4. The present level of temperature is near the average for the curves shown for both Northern hemisphere cases, and below several previous peaks
  5. The “Little Ice Age” and “Medieval Climate Optimum” show up in both Northern hemisphere cases
  6. The present temperature is not unusually high for the Antarctic

Figure 3. Temperature variations from the Greenland glacier ice core, the Sargasso Sea sediment core, and the Antarctic ice core. All 3 curves have lined up dates, and have the same vertical scale size.


The trend of the temperature for the Greenland and Sargasso Sea curves is also generally decreasing from 3,000 years ago, and the “Little Ice Age” was a cold and long lasting period. There are several other locations with indicated local temperature variation in this time period that generally tend to agree with the extent of the temperature variation during the little ice age and medieval climate optimum, and all show large variations occurring over the entire time period. If the present temperature is not unusual based on the above comparisons, why the AGW claims? In fact, it is based on two observations:

  1. The temperature has been warming over the last century and has increased the most within that period in the last 30 or so years.
  2. The CO2 and Methane levels have increased a lot over the last 30 to 60 years, and ice core records show them to be higher than any other time in the last several hundred thousand years.

It is clear that we get excited at anything different that happens in a time period that spans a large fraction of a lifetime, and even dominates recent history, even if it is not unusual compared to time periods more distant in the past. Also, the claim that increasing CO2 (and Methane), likely with a significant contribution from human activity, can cause some global warming does have some theoretical and computational basis. The problem is that all of the physics governing the Earth’s climate, including ocean currents and cloud feed back, as well as particulate effects are not fully understood, and generally are put into models in artificially selected forms to try to force the models to agree with actual measurements. A discussion of one possible problem with the theories and models is made in: http://www.drroyspencer.com/research-articles/satellite-and-climate-model-evidence/


If we go back even further in time for the present interglacial period than shown in figure 3, even higher temperatures and larger temperature variations are encountered. While we clearly are presently in a period of warming (or at least were up to the last few years), there is no indication that this is an unusual period of warming! If the present were unusual, then all previous times of rapid change and high levels would also have to be unusual, and where is the anthropogenic causes for those times? However, it is not certain that anthropogenic causes are not significant factors in the recent warming, so a “what if” case has to be examined. For the following, the assumption is made that the CO2 increase is dominated by human activity and that this increase is assumed to be the cause of a significant part of the temperature rise. Five questions need to be addressed:

1) Is it likely that the anthropogenic greenhouse gas levels will continue to increase?

2) Has the increase in anthropogenic greenhouse gasses been the dominant contributor to the recent high global average temperature?

  1. Are there other problems (or advantages) from increasing CO2?
  2. Is it likely that the temperature will continue to increase significantly (and if it does, is this necessarily bad)?
  3. Has this temperature rise (whatever the cause) had a significant effect on rising sea level and changes in weather?

The answer to the first question is probably yes. However the rate of increase is less certain, since the present increasing trend may only be a transient lag in the ability of the Earth to come to a new equilibrium from human activity. The level will probably remain higher than previous levels, but when it will eventually level off, slow down, or just keep increasing, is not clear. A CO2 level of between 400 and 500 ppm, or even a bit higher may be possible (but not certain) by 2100 absent heroic efforts to reduce the rise. There is no reasonable basis for increases much beyond this, mainly due to the finite availability of easily obtained carbon based fuels. It should also be noted that the methane level, which had increased considerably from prior to 1850 to the mid 1990’s, has essentially leveled off for the last decade, so is not a factor in additional warming.


Question 2 can be restated as: how much of the temperature increase in the last 150 years is due to the CO2 (and methane) increase, and how much due to a general recovery from the Little Ice Age. I don’t think we can accurately answer that, but it appears almost certain that human activity did not cause much more than about 0.3OC of the increase, based on the net rise from the local peak from about 1940 to the latest trend at the end of 2008. This maximum plausible contribution is much less than the expected increase blamed on human activity for this time period. The larger portion of temperature rise occurred prior to most of the input of CO2, so that rise cannot reasonably be blamed on this cause. In fact, the temperature had already increased somewhat from 1600 to 1850, so the rise from 1940 to 2008 is only about 1/4th the actual total rise (~1.2OC) from the low around 1600. From this we can conclude that anthropogenic increase in the CO2 may have contributed to the recent warming, but at most only a very modest share, and the present temperature trend is down!


This modest increase also brings up the issue of the calculation of expected temperature increase from models. These models directly calculate the expected increase from greenhouse effects, and then add expected positive feedback effects due to increased water vapor caused by the higher temperatures. The models (including positive feedback) anticipated a total rise of ~1.5OC just due to anthropogenic causes from 1850 to the present. It appears they are at least a factor of 5 too high if only 0.3OC of the increase was due to the greenhouse gasses as stated above. In fact, the main part of the temperature increase was clearly a recovery from the little ice age, and occurred prior to the vast majority of CO2 increase! There are also models that anticipate a negative feedback from increased water vapor forming the types of clouds that reduce the heating. It is not yet certain why the temperature is at the present level, but it is clear that the models have not yet been demonstrated as valid!


The temperature drop between 1940 and 1970, along with the underperforming model estimates were recently blamed on “Global Dimming” caused by particulate pollution. In fact the particulate pollution took a large dive when oil and gas rather than coal became major home and business fuels many years earlier (as seen in glacier records). More recently, particulates from growing economies like China, along with aircraft contrails, have added more dimming in recent times. The prediction has been made that once we (and the Chinese?) clean up pollution, this dimming will decrease and warming will be even worse than previously predicted. This presumes that greenhouse gas output is a separate problem from particulate pollution, but it is more likely that they will go up or down together.


A more recent study has concluded that an ocean current (Pacific Decadal Oscillation) not previously included in the “Global Warming Models” will dominate the effect of greenhouse gas temperature increases for about a decade or more (until about 2015 to 2030), and that this is the cause of the unexpected reversal of temperature trends for the last several years. It is curious that this new factor was not found until the temperature trend reversal became clear. It appears new factors will be found as needed to explain any deviations from the present “understanding of the Global Warming Problem”. Since the entire time of temperature rise used to show that there is an unusual period of heating was only about 30 years long (1970 to 2000), it now appears that we are told by global warming modelers that 30 years of a selected time of heating, sandwiched between one 30 year period of cooling, and being followed by another period of cooling (of unknown length, but at least 10 or more years), is proof of their claims – because it is a period of a local maximum temperature over a period of several hundred years. This despite the clear records that show such rapid variations and even maximum levels are common over the last several thousand years, and that the present level is not even as high as several other previous levels in that relatively recent time period.


The answer to the third question may be that there is a generally positive effect if the only change to the atmosphere was a significant increase in CO2 concentration. Most plant growth increases at higher levels of CO2. It also appears that some concerns for negative effects on ocean life from increased ocean acidity from CO2 were exaggerated, or even totally wrong (as will be discussed more later) (also see http://www.seafriends.org.nz/issues/global/acid.htm). A significant change in ocean pH would cause some changes, and there would be some winners and some losers in ocean life, but it appears that for realistic level changes this would not be a major problem. In fact, combining the slightly higher temperature with higher CO2 levels should significantly increase world crop growth if these are the only factors, and this is clearly a generally positive effect.


The fourth question combines the question of whether the natural temperature variation combined with the anthropogenic causes of temperature increase will result in significant continued temperature increase. The warming alarmists models predict a rise of an additional 2OC to 5OC as being likely by 2100, but I do not see that as being justified based on present information. Based on a combination of historical trends over the last several thousand years with the recent trends reasonably attributable to anthropogenic causes of temperature increase, it appears that some small additional increase might be reasonably possible (but not certain) by 2100, but most likely within a range <>OC, which would put it in the range of several warm periods in historical times that were particularly productive times.


There are two issues that have to be considered for the fifth question. The first is the effect of rising oceans. The site: http://sedac.ciesin.columbia.edu/mva/WR1987/WR1987.html models the expected increase in ocean level due to thermal expansion for a 0.6 OC to 1OC global temperature rise over several decades. They conclude that a total rise of only about 4 to 8 cm. would be caused by the temperature rise. In addition, several studies have concluded that the rise in sea level from Greenland and Antarctic ice cap melt water would not exceed 0.5 mm/year (5 cm/100 years), and this would probably drop off soon or even go negative due to the high altitude of the remaining glaciers, and increasing snowfall adding more ice than is removed by melting. Water from other melting glaciers has contributed to an additional level increase of about 0.5 to 1 mm/year for about the last 150 years, over the general warming trend effect on the oceans. However, much of the added source from melting glaciers is now decreasing, and some glaciers are nearly gone (many of these glaciers were actually formed during the little ice age). The total of all of these contributions is probably less than 15 cm, or 6 inches in the next 100 years, and even much less additional rise in following times. The most interesting point of the sea level problem is that only about 2 to 3 inches of the possible rise to 2100 is even plausibly related to anthropogenic causes of temperature increase, and this is the maximum that would be able to be stopped even with a 100% drop in human contribution! A huge but possible effort costing TRILLIONS of dollars and negatively impacting growing economies most would likely only prevent less than 1 inch of the rise!


A second issue of the consequence of temperature rise is possible severe changes in weather. There have been many claims of super storms, tornados, heavy rain, and drought associated with the temperature changes. Keep in mind that the temperature difference between the low and high latitudes is the driver for these storms, and the main predicted effect of AGW is to DECREASE this difference!! It is very likely that there will be slightly fewer hurricanes, but they may tend to be slightly stronger due to the higher absolute humidity possible with higher temperature. The issue of more frequent and stronger tornados is difficult to evaluate, but records going back about 100 years do not show a significant trend of increasing overall activity of the stronger tornados. There are periods of large numbers and strong tornados going back in history that pre-dated the period of recent warming. The recent severe US tornado outbreak may even have been a record for recorded times (keeping in mind that fairly complete records only cover a very short period), but any one-year record may be unusually large or small, and only longer time trends are meaningful. The average rainfall will likely increase in some locations due to higher absolute humidity possible at higher temperatures, and the locations of high and low average rainfall (and drought) would shift somewhat.


There would be winners and losers in any change in climate and weather, but the overall effect of higher CO2 and slightly higher temperature would be a more productive Earth. The real fact to face is that there always is change in climate and weather over periods of several decades to centuries. We should not make heroic efforts to change the climate but concentrate on being able to adapt to the changes. This is especially important when we do not know for sure if our effort may actually worsen the situation,


The possible problems with CO2 data

The CO2 curve of figure 1 was actually made from three separate parts. The data from one location (Mauna Loa in Hawaii) was used from 1958 to the present. Additional locations started making measurements about 1980, and agreed reasonably well with the Mauna Loa results. A few selected land based measurements made in the previous several decades were also spliced to the Mauna Loa results. Glacial ice core data trends with a large offset time correction were then spliced to the previous two sources (with offset selected to make it fit!). This was then the source of the CO2 curve from 1850 to the present. The ice core data was then also used to show the CO2 variation over the last several hundred thousand years. It should be noted that the CO2 level was obtained directly from gas bubbles trapped in the ice cores.


There are numerous potential problems with some of the CO2 data in figure 1. The Mauna Loa and other recent direct measurements are probably basically reliable as a “background level”. However, far bigger uncertainties occur for the other two parts that made the CO2 curve in figure 1, and also in the longer time ice core records. A few selected sets of direct measured CO2 data made before the Mauna Loa measurements started were used to extend the curve to earlier times. A recent paper by Ernst Beck, who reviewed all of the older direct CO2 measurements, concluded that the papers selected to show the CO2 measurements before Mauna Loa were cherry-picked to agree with prior conceptions. All of the earlier measurements were limited in that they were made over land, and could have been biased by industrial activity, the proximity of cities, agriculture, etc. (and these limitations in reliability could also be applied to tree ring data). In fact Beck’s summary paper shows what may be unrealistic high CO2 data levels, especially in the early 1800’s and the period of the 1930’s, but the point is that this was direct measured data at numerous locations, and generally showed that CO2 levels may have been significantly higher in the near past than claimed. There are no clearly reliable direct measurements in this period that prove otherwise. The best approach probably would be to reject all of the direct measured CO2 data collected before the Mauna Loa and other recent stations were established due to the uncertainty of the applicability of these measurements to determine the global average background level.


The questionability of ice core CO2 determination

CO2 determined from glacier ice core gas bubbles has been used to indicate the atmospheric CO2 level at the time the bubbles formed. The frozen core sample is crushed to obtain the trapped gas from the bubbles and directly find the CO2 concentration. There is no direct supporting evidence that this is a valid technique. In order to examine the reasonableness of the process, the following discussion examines three possible issues.


The first issue arises from the porous nature of the compressing ice, which may take from about a hundred years to possibly as long as thousands of years before it seals off completely. This would result in diffusion averaging of composition, and very likely lose resolving even large variations in atmospheric CO2 occurring over shorter periods than the time to seal off. This is probably the cause of the near constant indicated CO2 composition over long periods.


The second issue arises from the comparison of levels and trends of CO2 made by other techniques. In particular, a set of measurements was made using the inverse relation between atmospheric carbon dioxide concentration and stomatal frequency in tree leaves to provide a method for detecting and quantifying century-scale carbon dioxide fluctuations (Wagner, F., Bohncke, S.J.P., Dilcher, D.L., Kurschner, W.M., van Geel, B. and Visscher, H. 1999. Century-scale shifts in early Holocene atmospheric CO2 concentration. Science 284: 1971-1973.). The results indicated CO2 levels varied considerably over the last several thousands years, and in some cases came much closer to present high levels than indicated in ice cores (to at least as high as ~348 ppm). In fact, a significant part of the difference between stomatal frequency based data and ice core data may be related to the first issue above.


The third issue relates to the CO2 content of trapped air being selectively reduced by dissolving in either a quasi-liquid or liquid layer. According to an article by John S. Wettlaufer and J. Greg Dashbears at: http://www.bushwalking.org.au/FAQ/FAQ_MeltBelowZero.htm


“Ice has a quasi-liquid film, a natural state of solid ice formed by a process called surface melting, at temperatures down to near –40OC”. This layer has some structural characteristics of the solid below it but has the mobility and solubility of a fluid. This layer can contain dissolved gases such as CO2. In addition, there is the possibility of some liquid water being present in the ice even at temperatures below normal freezing. The rise in summer temperature and prolonged sunlight could even form melt layers (possibly subsurface) during glacier formation. When the melt liquid forms, the high solubility in the liquid could preferentially (compared to O2 and N2) take in a significant quantity of CO2. At release of pressure, when cores are drilled and raised, there could be some preferential CO2 loss from the micro cracks in the cores, or the ice could retain excess CO2 separate from the air bubbles.


Conclusions from the above are:

  1. The process of the formation of glaciers may result in temporal smoothing of results on a time scale long enough to miss large level variations of CO2 lasting possibly hundreds of years.
  2. Some alternate techniques that determine CO2 concentration over time contradict the slow changing ice record, but this may in fact be due to 1). This could mean present levels are not quite so extremely high or unusually fast changing as thought.
  3. Quasi-liquid films and liquid water occurring during glacier formation could be a significant source of CO2 removal from trapped air bubbles, especially near the freezing point. Significant amounts of CO2 may preferentially dissolve even in a small amount of quasi-liquid or liquid. This could result in a preferential reduction of the CO2 concentration in the larger gas bubbles.

The final result is that there is some room for doubt for the reliability of ice core bubble composition to determine older CO2 concentrations in air, and a more reliable method to determine older CO2 atmospheric concentrations is badly needed.


Problems with seawater pH determination, and its effect on AGW predictions


Researchers aboard the Wecoma, an Oregon State University research vessel, discovered that significantly “acidified” seawater (pH = 7.6) from the deeper ocean is being “upwelled” within 20 miles from shore along the Pacific coast (www.physorg.com/news130693309.html). The researchers stated that this water was on the surface about 50 years ago. This despite the assumed fact that the atmospheric CO2 level was no higher than 310 ppm around the time the water would have been on the surface (according to current theories). The present level of 385 ppm of CO2 in the air has made surface pH levels go to 8.1. The CO2 level would have to be >1,000 ppm to come close to the pH value of 7.6 found from the upwelled seawater. The researchers indicated that phytoplankton blooms, caused by the slightly elevated CO2 levels, decayed to raise the CO2 level even higher. Since the blooms took Carbon out of the water to form, and since the blooms could not change the overall Carbon mass balance, the local CO2 concentration would have to be balanced by depletion of CO2 somewhere else. This indicates that measuring local seawater pH levels is not necessarily a valid indicator of average atmospheric CO2 level and its change over time, and thus its effect on sea life.


If you type:

[PDF] SEAWATER pH AND ANTHROPOGENIC CARBON DIOXIDE

in Google, and hit search, then hit the first site with that title shown, this will allow you to download a pdf of a paper by Marsh. That paper relates CO2 concentration to seawater pH more accurately than currently used linear approximations, and concludes the current projected pH levels that are widely used are unrealistic even if the CO2 level rose to over 2 times present levels! It also discusses ocean mixing, and it shows that mixing is likely much faster than simple models show. If surface water can be pushed to a large depth in a relatively short time, the increase in CO2 concentration due to human activity would be reduced by mixing with larger volumes of seawater than just the uppermost mixing layer. There is no logical reason the well-mixed seawater pH would go as low as feared, just based on the maximum amount of new Carbon that is available from anthropogenic causes and the dilution effect that is assured.


We do need to look at “what if” cases to be sure we are not risking catastrophe. Even if the atmospheric CO2 levels increase as much as the AGW predictions, and assuming this resulted in the projected drop in surface ocean pH (using the unrealistic linear extrapolation method), the results would still not be as unfavorable as stated. The following web sites discuss the effect on Earth’s calcifying corals and other marine organisms caused by lowering the calcium carbonate saturation state of seawater due to lowering the pH. The sites also have connections to other related topics including increasing temperature effects. The conclusions at these sites contradict AGW warnings on the problems that may occur in the oceans due to increasing CO2 in the atmosphere.

http://www.co2science.org/articles/V11/N21/EDIT.php

http://www.co2science.org/subject/c/summaries/calcification.php

http://www.co2science.org/subject/c/summaries/calcificationother.php

If AGW and ocean acidification are not problems even with some CO2 increases, why the big issue. In the end, the improved productivity of the biosphere due to higher CO2 would mainly be a blessing. There is no general downside and AGW concerns are misplaced for that time scale. However, the problems of pollution (not greenhouse gasses), and the increasing cost of fossil fuels, are driving efforts to find alternate sources of energy. This will cause the increase of CO2 to slow down and eventually reverse long before CO2 levels get high enough to be a real problem, even if most of the rise is anthropogenic.


The Methane issue and Siberia

It is interesting to note from figure 3 (and also from data from earlier in the present interglacial) that periods of rapid temperature increase and long periods of temperatures higher than present often occurred. It is certain that methane was released from Siberia and other sites (Artic seabed, Alaska, etc.) at those times as well as seems to be happening at the present. Where is the indication of recent (<3,000>


Some final points:

We know from many records that significant changes in temperature and climate have frequently occurred through historical as well as Geological time periods, and often result in significant consequences.


Previous interglacial periods tended to last 10,000 to 20,000 years, and in fact most did not have temperatures as slow changing as the present one. Since the present interglacial started about 18,000 years age, and reached the plateau about 11,000 years ago, we probably should be more concerned with a possible impending major ice age than a fraction of a degree or so of warming. In fact, the best possible outcome would be that the (relatively modest) contribution from AGW might help delay the onset of a new ice age.


The magnetic field of the Earth has changed a lot over geological times. There were periods of weakening and then reversal occurring about every 200,000 years until about 780,000 years ago. At the present time, the field is again weakening. If the field weakens too much, the Earth’s magnetosphere would not block cosmic rays and Solar ions as well, and this could greatly affect cloud structure and thus weather. The Solar radiation and magnetic storms could also profoundly affect power transmission and electronics.


Preparing for the possibility of an impending ice age along with the possible consequences of a reduction in Earth’s magnetic field are real concerns. Concern with relatively small effects of possible anthropogenic caused global warming is a misplaced distraction, and will probably lead to the public losing confidence in scientists, and could weaken the support needed when real problems occur.


Decreasing availability of oil and anthropogenic pollution (not greenhouse gasses) are real issues. Acid rain, smog, and dirty water sources do need to be fixed. The problems associated with high fuel prices, and dependence on sources of energy from possibly less than friendly foreign countries are critical. While we can’t solve the problems with a single magic bullet, more nuclear power plants, along with wind and Solar power, could fill much of the gap. There are solutions, but first we have to identify the correct problems.

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