Global Warming Empirical Evidence

SEARCH BLOG: GLOBAL WARMING

From the New York Times:

Emissions Already Affecting Climate, Report Finds
By JAMES KANTER and ANDREW C. REVKIN
Published: April 6, 2007

BRUSSELS, April 6 — Earth’s climate and ecosystems are already being affected, for better and mostly for worse, by the atmospheric buildup of smokestack and tailpipe gases that trap heat, top climate experts said today.

And while curbs in emissions can limit risks, they said, vulnerable regions must adapt to shifting weather patterns and rising seas.

The conclusions came in the latest report from Intergovernmental Panel on Climate Change, which has tracked research on human-caused global warming since being created by the United Nations in 1988. In February, the panel released a report that for the first time concluded with 90-percent certainty that humans were the main cause of warming since 1950. But in this report, focusing on the impact of warming, for the first time the group described how species, water supplies, ice sheets, and regional climate conditions were already responding.

At a news conference capping four days of debate between scientists and representatives from more than 100 governments, Martin Parry, the co-chairman of the team that wrote the new report, said widespread effects were already measurable, with much more to come.

“We’re no longer arm waving with models,” said Dr. Parry, who identified areas most affected as the Arctic, Sub-Saharan Africa, small islands and Asia’s sprawling, crowded, flood-prone river deltas. “This is empirical information on the ground.”

The report said that climate patterns were shifting in ways that would bring benefits in some places — including more rainfall and longer growing seasons in high latitudes, opening Arctic seaways, and reduced deaths from cold — but significant human hardship and ecological losses in others.

The panel said the long-term outlook for all regions was for trouble should temperatures rise 3 to 5 degrees fahrenheit or so, with consequences ranging from the likely extinction of perhaps a fourth of the world’s species to eventual inundation of coasts and islands inhabited by hundreds of millions of people....

From Climate Science:

Dr. Ben Herman
Director of the Institute of Atmospheric Physics
Department of Atmospheric Sciences at the University of Arizona
Published: April 6, 2007

Now, the models also predict that the mid tropospheric warming should exceed that observed at the ground, but satellite data [empirical information] contradicts this. We have been looking into this problem here at the University of Arizona, and have concluded that the satellite temperatures from the UAH group are the most accurate, and these, after being corrected for stratospheric cooling, orbital drifts, hot target changes, etc. still show less tropospheric warming than do the ground temperatures. A paper addressing this will be submitted for publication shortly. If the models cannot accurately predict the temperature trends in the mid-troposphere, how accurate can they be at the ground?

I am also puzzled by the local area predictions that are becoming almost a daily happening. Here in Arizona, we are told we will experience severe drought, unbelievably hot temperatures, etc. If the climate warms enough, we would expect the global weather patterns to migrate poleward. While this would likely diminish our winter rains here in Arizona, it would also advance the Monsoon easterlies further north in the summer, likely producing more summer rains and a longer summer rainy season.It would also cause cooler summer temperatures as the sub-tropical high would be further north and we would not be exposed to the subsidence that results in our high temperatures now. The increased cloud cover due to the increase in monsoon rains would also help cool daytime temperatures Whether the net result would be a decrease, an increase, or no net change in rainfall I can’t say, but the models can’t predict this either. Yet the forecasts of what will happen are being made.

Another point I would also like to make is with respect to the rather rapid increase in temperatures that we have experienced over the past 10-15 years. Can the models explain this by the addition of greenhouse gases? I don’t believe the increase in CO2 has taken on a similar shape.

The above are but a few examples of uncertainties that exist. There are others. I point them out only to raise the question as to how statements about our past warming, and even our future weather can be made with 90% certainty while such important questions still exist.

I guess it all depends on where you look for your empirical evidence.

With regard to the concept that warmer climates will bring extinction of 1/4 of all species... that does not jibe with the paleontological record. I'd like to understand that assertion a little better. This is the kind of prediction that showed up the other day in material I quoted about the Amazon dying from global warming. If you read the link to the history of the Amazon basin, you would have learned that the only major reduction of the rainforest was caused by the ice ages, not the hotter climates of the past.

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