Wobbling Earth and Climate Change Link

Global warming episodes that were interspersed between prehistoric ice ages were caused by regular wobbles in the earth's tilt, according to new evidence from the University of Newcastle in Australia.

Image courtesy of Wikipedia.

The research team, led by Russel Drysdale, suggest that the Earth emerges from ice ages due in large part to changes in the tilt of the planet in relation to the sun, otherwise known as its obliquity. This affects the total amount of sunlight each hemisphere receives in its respective summer, rather than the peak intensity of the solar radiation during the northern summer, according to the Discovery News.

The team studied sediment on the sea floor and compared the changes in the sea floor to similar material on the surface that can be accurately dated through samples taken from cave stalagmites.

The result is that the new date for the end of the second last ice age is thousands of years too early to be related to any increase in the intensity of the northern hemisphere summer as predicted by the Milankovitch Theory.

Instead, the researchers found that, in the past million years global warming events have occurred every second or third cycle of the Earth's changing obliquity, which occurs every 41,000 years.

‘90% of the last million years, the normal state of the Earth’s climate has been an ice age’

From the American Thinker

The Coming Ice Age

By David Deming

Those who ignore the geologic perspective do so at great risk. In fall of 1985, geologists warned that a Columbian volcano, Nevado del Ruiz, was getting ready to erupt. But the volcano had been dormant for 150 years. So government officials and inhabitants of nearby towns did not take the warnings seriously. On the evening of November 13, Nevado del Ruiz erupted, triggering catastrophic mudslides. In the town of Armero, 23,000 people were buried alive in a matter of seconds.

For ninety percent of the last million years, the normal state of the Earth’s climate has been an ice age. Ice ages last about 100,000 years, and are punctuated by short periods of warm climate, or interglacials. The last ice age started about 114,000 years ago. It began instantaneously. For a hundred-thousand years, temperatures fell and sheets of ice a mile thick grew to envelop much of North America, Europe and Asia. The ice age ended nearly as abruptly as it began. Between about 12,000 and 10,000 years ago, the temperature in Greenland rose more than 50 °F.

We don’t know what causes ice ages to begin or end. In 1875, a janitor turned geologist, James Croll, proposed that small variations in Earth’s orbit around the Sun were responsible for climate change. This idea enjoyed its greatest heyday during the 1970s, when ocean sediment cores appeared to confirm the theory. But in 1992, Ike Winograd and his colleagues at the US Geological Survey falsified the theory by demonstrating that its predictions were inconsistent with new, high-quality data.

The climate of the ice ages is documented in the ice layers of Greenland and Antarctica. We have cored these layers, extracted them, and studied them in the laboratory. Not only were ice ages colder than today, but the climates were considerably more variable. Compared to the norm of the last million years, our climate is remarkably warm, stable and benign. During the last ice age in Greenland abrupt climatic swings of 30 °F were common. Since the ice age ended, variations of 3 °F are uncommon.

For thousands of years, people have learned from experience that cold temperatures are detrimental for human welfare and warm temperatures are beneficial. From about 1300 to 1800 AD, the climate cooled slightly during a period known as the Little Ice Age. In Greenland, the temperature fell by about 4 °F. Although trivial, compared to an ice age cooling of 50 °F, this was nevertheless sufficient to wipe out the Viking colony there.

In northern Europe, the Little Ice Age kicked off with the Great Famine of 1315. Crops failed due to cold temperatures and incessant rain. Desperate and starving, parents ate their children, and people dug up corpses from graves for food. In jails, inmates instantly set upon new prisoners and ate them alive.

The Great Famine was followed by the Black Death, the greatest disaster ever to hit the human race. One-third of the human race died; terror and anarchy prevailed. Human civilization as we know it is only possible in a warm interglacial climate. Short of a catastrophic asteroid impact, the greatest threat to the human race is the onset of another ice age.

The oscillation between ice ages and interglacial periods is the dominant feature of Earth’s climate for the last million years. But the computer models that predict significant global warming from carbon dioxide cannot reproduce these temperature changes. This failure to reproduce the most significant aspect of terrestrial climate reveals an incomplete understanding of the climate system, if not a nearly complete ignorance.

Global warming predictions by meteorologists are based on speculative, untested, and poorly constrained computer models. But our knowledge of ice ages is based on a wide variety of reliable data, including cores from the Greenland and Antarctic ice sheets. In this case, it would be perspicacious to listen to the geologists, not the meteorologists. By reducing our production of carbon dioxide, we risk hastening the advent of the next ice age. Even more foolhardy and dangerous is the Obama administration’s announcement that they may try to cool the planet through geoengineering. Such a move in the middle of a cooling trend could provoke the irreversible onset of an ice age. It is not hyperbole to state that such a climatic change would mean the end of human civilization as we know it.

Earth’s climate is controlled by the Sun. In comparison, every other factor is trivial. The coldest part of the Little Ice Age during the latter half of the seventeenth century was marked by the nearly complete absence of sunspots. And the Sun now appears to be entering a new period of quiescence. August of 2008 was the first month since the year 1913 that no sunspots were observed. As I write, the sun remains quiet. We are in a cooling trend. The areal extent of global sea ice is above the twenty-year mean.

We have heard much of the dangers of global warming due to carbon dioxide. But the potential danger of any potential anthropogenic warming is trivial compared to the risk of entering a new ice age. Public policy decisions should be based on a realistic appraisal that takes both climate scenarios into consideration.

Is Methane The Cause Of Past Ice Age Global Warming?

By studying gas bubbles frozen in ancient Greenland ice, University of Victoria researchers have dispelled a popular theory that marine gas hydrates caused a significant release of methane gas into the Earth’s atmosphere, triggering a period of global warming at the end of the last ice age.

“Understanding the behaviour of global atmospheric methane is important because it’s the third strongest greenhouse gas after carbon dioxide and water vapour,” says biogeochemist Dr. Michael Whiticar, part of the Canada-U.S. team that conducted the study. “Atmospheric methane concentrations have increased about 250 per cent in the last 250 years, and they continue to rise about one per cent a year.”

Methane in the Earth’s atmosphere is an important greenhouse gas with a global warming potential of 25 over a 100-year period. This means that a methane emission will have 25 times the impact on temperature of a carbon dioxide emission of the same mass over the following 100 years. Methane has a large effect for a brief period (about 10 years), whereas carbon dioxide has a small effect for a long period (over 100 years). Because of this difference in effect and time period, the global warming potential of methane over a 20 year time period is 72.

The Earth’s methane concentration has increased by about 150% since 1750, and it accounts for 20% of the total radiative forcing from all of the long-lived and globally mixed greenhouse gases.

The team, which included PhD student Hinrich Schaefer, studied the concentration and carbon isotope fingerprints of the methane in the ice off Pakitsoq, Greenland. The technique enabled researchers to investigate the changes in sources and sinks of atmospheric methane - perhaps analogous to today’s rapid rise in the Pleistocene and Holocene ages.

“Methane is a gas that makes a significant contribution to global warming but has gone largely unnoticed by the public and some policy-makers,” says Schaefer, now pursuing postgraduate studies at Oregon State University. “Its concentration has more than doubled since the industrial revolution, from things like natural gas exploration, landfills and agriculture. We need to know whether rapid increases of methane in the past have triggered global warming or have just been a reaction to it.”

According to Whiticar, the study shows that massive destabilization of methane hydrates along the oceanic shelves and the corresponding release of methane to the atmosphere can’t be responsible for detonating the rise in greenhouse gases 12,000 years ago.

“Our work supports the belief that wetlands and permafrost layers are responsible for the enhanced sources of methane to the atmosphere. This is critical knowledge because again, today, we see rapid retreating of our northern permafrost boundaries due to Arctic warming.”

The findings of the team’s research were featured in an article in the Aug. 25 edition of the international journal Science. Funding for the Canadian aspects of the work was provided by the Canadian Foundation for Climate and Atmospheric Sciences, the Natural Sciences and Engineering Research Council and the Canada Foundation for Innovation, with collaborations with Oregon State University, the University of Colorado, and the Scripps Institution of Oceanography at the University of California at San Diego.

Could Global Warming Cause A New Ice Age?

In the movie The Day After Tomorrow, there are many special effects including an ice event caused by global warming. Much of the science of the movie has been called into question. However, there may be some truth to the idea that global warming could cause an ice age.

The theory starts with an understanding of why Europe and Scandinavia are not colder already. After all, other places at the same latitude are covered with ice and permafrost. Alaska and Greenland are both as close to the North Pole as Europe. Yet, it is not global warming that keeps Europe warm.

The ocean currents called the Gulf Stream bring warm waters up to the UK and Europe from the Caribbean. These waters warm the countries around their path. This is what causes the UK, Europe, and Scandinavia to have such a nicer climate than, say, Alaska. Global warming has nothing to do with that.

An important factor about the Gulf Stream is that to keep the Great Conveyor Belt going, cool water must feed back into the loop and be brought back to the point in the Caribbean where the process began. This keeps the water moving.

Global warming is significant in that it could slow the Gulf Stream, or even stop it. If this were to happen, the cold waters would stay in the area of Europe, the UK, Scandinavia, and the Northeastern US. It could mean an ice age for those regions.

In every major cooling event, such as the last great Ice Age, the Gulf Stream has been significantly weakened. This can happen for different reasons. In current times, it can happen due to global warming brought on by human activities such as the burning of fossil fuels.

If the new Ice Age happens, it will likely be due to the melting of the polar ice. This will dump large quantities of cold, fresh water into the ocean. It would disrupt the Gulf Stream and cause the cooling of many areas that now have milder climates. Global warming will be the cause.

An ice age will probably not happen gradually, either. This is a phenomenon that takes place rather quickly. Perhaps it does not happen as fast as the ice event in The Day After Tomorrow. However, it could happen within a few short years with global warming being to blame.

The return flow of cold water from Greenland, which goes back to the Caribbean, has already showed a weakening in the last 50 years. There has been a 20% decline in the amount of current flowing in this direction. It only makes sense that the warm waters coming from the Caribbean have lessened too.

These currents are a part of the world-wide network of currents called the Global Thermohaline Circulation. This global warming could then cause a slowing or stoppage of the Gulf Stream affecting the entire earth.

The statistics are used to answer the question of whether an ice age could be caused by global warming. Observations have been made of current data and historical information gleaned by studying the ocean and the lands around it. With all the information at hand, it appears that it is indeed possible that global warming could lead to an Ice Age.

CO2, Temperatures, and Ice Ages

Guest post by Frank Lansner, civil engineer, biotechnology.

(Note from Anthony - English is not Frank’s primary language, I have made some small adjustments for readability, however they may be a few passages that need clarification. Frank will be happy to clarify in comments)

It is generally accepted that CO2 is lagging temperature in Antarctic graphs. To dig further into this subject therefore might seem a waste of time. But the reality is, that these graphs are still widely used as an argument for the global warming hypothesis. But can the CO2-hypothesis be supported in any way using the data of Antarctic ice cores?

At first glance, the CO2 lagging temperature would mean that it’s the temperature that controls CO2 and not vice versa.

Click for larger image Fig 1. Source:
http://www.brighton73.freeserve.co.uk/gw/paleo/400000yrfig.htm

But this is the climate debate, so massive rescue missions have been launched to save the CO2-hypothesis. So explanation for the unfortunate CO2 data is as follows:

First a solar or orbital change induces some minor warming/cooling and then CO2 raises/drops. After this, it’s the CO2 that drives the temperature up/down. Hansen has argued that: The big differences in temperature between ice ages and warm periods is not possible to explain without a CO2 driver.

Very unlike solar theory and all other theories, when it comes to CO2-theory one has to PROVE that it is wrong. So let’s do some digging. The 4-5 major temperature peaks seen on Fig 1. have common properties: First a big rapid temperature increase, and then an almost just as big, but a less rapid temperature fall. To avoid too much noise in data, I summed up all these major temperature peaks into one graph:

Fig 2. This graph of actual data from all major temperature peaks of the Antarctic vostokdata confirms the pattern we saw in fig 1, and now we have a very clear signal as random noise is reduced.
http://wattsupwiththat.com/2009/01/30/co2-temperatures-and-ice-ages/