“The Debate Is Over”: Human Driven Climate Change

Global warming ‘unquestionably’ due to humans: France

AFP, Thursday, October 28th, 2010

PARIS (AFP) – Global warming exists and is unquestionably due to human activity, the French Academy of Science said in a report published Thursday and written by 120 scientists from France and abroad.

“Several independent indicators show an increase in global warming from 1975 to 2003. This increase is mainly due to the increase in the concentration of carbon dioxide,” the academy said in conclusion to the report.

“The increase in carbon dioxide, and to a lesser degree other greenhouse gases, is unquestionably due to human activity,” said the report, adopted unanimously by academy members.

The report contradicts France’s former education minister Claude Allegre, a geochemist, who published a book called “The Climatic Deception” which claimed that carbon dioxide was not linked to climate change.

The report was commissioned in April by Minister for Research Valerie Pecresse in response to hundreds of environmental scientists who complained that Allegre in particular was disparaging their work.

Allegre is a member of the Academy of Sciences and also signed off on the report.

“He has the right to evolve,” the academy’s president Jean Salencon said. Pecresse said: “The debate is over.”

more here…

Almost two years I wrote that for years as the planet warms the arctic icecap has been melting and retreating.

Many of us have long known that arctic wildlife like polar bears, gray whales, killer whales, narwhals, seals, and arctic fish and bird populations, as well as arctic coastal human settlements, are in danger of eventual extinction as their natural habitat has been retreating, but what most of us haven’t known is the extent and speed of the retreat.

Because of recent ice loss, Arctic surface air temperatures are warmer than normal, and much warmer than scientists expected to find.

As the ice has been melting the growing spans of open water absorb more sunlight than the ice previously did, so as more open water becomes uncovered, the remaining ice will melt more quickly. This will itself accelerate the rate of warming and lead to more ice loss. In addition, global climate change is likely to drive warmer ocean currents into the Arctic region.

You get the picture. What has developed is a positive feedback loop with dramatic implications for the entire Arctic, and for the rest of the planet, and for all life on Earth. It’s been nice knowing you.

The shrinkage of the Arctic ice cap is viewed with much alarm by climate researchers and scientists, as it appears to perturb important ocean currents elsewhere, notably the Gulf Stream, which gives western Europe its balmy climate.

A report in early 2009 by scientists Muyin Wang of the Joint Institute for the Study of Atmosphere and Ocean and James E. Overland of the National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Laboratory, was published by the American Geophysical Union’s journal Geophysical Research Letters, forecasting nearly complete icecap loss by 2037:

September 2008 followed 2007 as the second sequential year with an extreme summer Arctic sea ice extent minimum. Although such a sea ice loss was not indicated until much later in the century in the Intergovernmental Panel on Climate Change 4th Assessment Report, many models show an accelerating decline in the summer minimum sea ice extent during the 21st century. Using the observed 2007/2008 September sea ice extents as a starting point, we predict an expected value for a nearly sea ice free Arctic in September by the year 2037. The first quartile of the distribution for the timing of September sea ice loss will be reached by 2028. Our analysis is based on projections from six IPCC models, selected subject to an observational constraints. Uncertainty in the timing of a sea ice free Arctic in September is determined based on both within-model contributions from natural variability and between-model differences.

Received 6 February 2009; accepted 5 March 2009; published 3 April 2009.

Citation: Wang, M., and J. E. Overland (2009), A sea ice free summer Arctic within 30 years?, Geophys. Res. Lett., 36, L07502, doi:10.1029/2009GL037820.

They expect the area covered by summer sea ice to decline from about 2.8 million square miles to 620,000 square miles within 30 years, with frightening implications for both arctic wildlife and the planet. And for humans.

We have maybe 28 years left.

Photos from US spy satellites declassified by the Obama White House [in July 2009] provide the first graphic images of how the polar ice sheets are retreating in the summer. The effects on the world’s weather, environments and wildlife could be devastating

Satellite images of polar ice sheets taken in July 2006 and July 2007

showing the retreating ice during the summer.

View larger image

Graphic images that reveal the devastating impact of global warming in the Arctic have been released by the US military. The photographs, taken by spy satellites over the past decade, confirm that in recent years vast areas in high latitudes have lost their ice cover in summer months.

The pictures, kept secret by Washington during the presidency of George W Bush, were declassified by the White House last week. President Barack Obama is currently trying to galvanise Congress and the American public to take action to halt catastrophic climate change caused by rising levels of carbon dioxide in the atmosphere.

One particularly striking set of images – selected from the 1,000 photographs released – includes views of the Alaskan port of Barrow. One, taken in July 2006, shows sea ice still nestling close to the shore. A second image shows that by the following July the coastal waters were entirely ice-free.

The photographs demonstrate starkly how global warming is changing the Arctic. More than a million square kilometres of sea ice – a record loss – were missing in the summer of 2007 compared with the previous year.

Nor has this loss shown any sign of recovery. Ice cover for 2008 was almost as bad as for 2007, and this year levels look equally sparse.

“These are one-metre resolution images, which give you a big picture of the summertime Arctic,” said Thorsten Markus of Nasa’s Goddard Space Flight Centre.

— UK Guardian – The Observer, Sunday 26 July 2009

In July 2006 Dr. James Hansen, Director of the NASA Goddard Institute, warned that:

If human beings follow a business-as-usual course, continuing to exploit fossil fuel resources without reducing carbon emissions or capturing and sequestering them before they warm the atmosphere, the eventual effects on climate and life may be comparable to those at the time of mass extinctions. Life will survive, but it will do so on a transformed planet. For all foreseeable human generations, it will be a far more desolate world than the one in which civilization developed and flourished during the past several thousand years.

The business-as-usual scenario yields an increase of about five degrees Fahrenheit of global warming during this century

How much will sea level rise with five degrees of global warming? Here too, our best information comes from the Earth’s history. The last time that the Earth was five degrees warmer was three million years ago, when sea level was about eighty feet higher.

Eighty feet! In that case, the United States would lose most East Coast cities: Boston, New York, Philadelphia, Washington, and Miami; indeed, practically the entire state of Florida would be under water. Fifty million people in the US live below that sea level. Other places would fare worse. China would have 250 million displaced persons. Bangladesh would produce 120 million refugees, practically the entire nation. India would lose the land of 150 million people.