Friday, April 29, 2005

Smoking Gun?

This story made me seriously question what I believe about global warming:

'Smoking gun' on humans and global warming claimed.

[...]Using ocean data collected by diving floats, U.S. climate scientists released a study Thursday that they said provides the "smoking gun" that ties manmade greenhouse gas emissions to global warming.

[...]Average atmospheric temperatures rose about 1 degree Fahrenheit in the 20th century, and the Intergovernmental Panel on Climate Change, a U.N.-organized network of scientists, says computer modeling shows they will rise between 2.5 degrees and 10.4 degrees Fahrenheit by the year 2100, depending on how well emissions are controlled.
Is it true? It human-induced, runaway global warming a confirmed fact?


If you read a longer account of the article you come away with a very different story:

The study, which appears in this week's Science Express, a feature of Science magazine, reveals that Earth's current energy imbalance is large by standards of Earth's history. The current imbalance is 0.85 watts per meter squared (W/m2) and will cause an additional warming of 0.6 degrees Celsius (1 degree Fahrenheit) by the end of this century.
One degree? Not 2.5-10.4. Just one degree (the article goes on to specuate that there is already a degree stored in the ocean so we may be talking about two degrees total).

Two things here:

1) Although it is billed as a smoking gun, there is nothing in the study to show where the warming is coming from. It could be CO2 -induced, it could be solar, or it could be something else.

2) 1-2 degrees is moderate cooling. Crichton was nominated for a Flat Earth Award for saying that warming in the 21st century would be in that range instead of in the much higher range forcast by global warming computer models. Here is the passage from the Flatties: "Crichton “guesses” that the planet will warm 1.46 degrees Fahrenheit over the next hundred years." Now that NASA has confirmed this figure, maybe they will get the next Flat Earth Award.

For a different take on the findings, see William Kininmonth, a former head of Australia's National Climate Centre and a member of Australia's delegations at various rounds of United Nations climate treaty negotiations.
"The paper implies that it is possible to estimate quite accurately the global radiation imbalance," he told BBC News; other researchers, he says, have "explained why it is not possible to measure the imbalance with an accuracy better than several watts per metre squared"

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