How Much Consensus Is There On Global Warming?

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http://www.energyandthelaw.com/files/2013/04/Global-Warming.jpgThis post is not from a global warming denier. But I do appreciate even-handed assessments of the situation. Here are two reports that fit the bill. 

In the London Telegraph, Geoffrey Lean says that recent research suggests climate change might not be as catastrophic as the gloomiest forecasts. But he warns that it will be decades, if not centuries, before the full consequences of today’s emissions of CO2 become clear.

Rapid temperature increases in the 1980’s and ‘90s have dramatically slowed for the past decade even as CO2 emissions have continued to increase. But he does not agree with skeptics who say that global warming has stopped. As an example, he cites that eight of the nine hottest years on record have all occurred since 2000. His point is that CO2 may be less potent than has been thought in heating the planet, and soot or “black carbon” may be more to blame.

Recent papers from different, well established scientists, suggest that the rise of temperatures may be closer to the 1.5º C than the 4.5º C range of increase in global temperatures estimated by the IPCC.

The Economist reports that there is “a mismatch between rising greenhouse gas emissions and not-rising temperatures, which is a big puzzle to scientists.”

They also warn that this does not mean that global warming is delusion. Flat as they are, temperatures in the first decade in the 21st century are 1º C above their level in the first decade of the 20th century. They offer several scenarios: Perhaps the 1990s when temperatures were rising was the anomalous period, and not 2000 through 2010. Or the climate may respond differently to higher concentrations of CO2 in ways that are not properly understood.

An unpublished report by the Research Council of Norway (not yet peer reviewed), a government-funded body using a method different from the IPCC’s, believes that the most likely effect of doubling CO2 omissions would be a rise of 1.9º C. This is consistent with projections from other research projects. The IPCC estimates the answer to be about 3º C.

There is a discussion of several different models using several approaches to predict the effect of climate change, which is too much science for a lawyer.

They also agree that soot, or black carbon (from diesel and Third-World cooking fires), may be more to blame than CO2.

Finally, several lines of evidence show that observed trends are pushing temperature predictions down, whereas compter models are pushing temperature predictions up.

And a bonus from the Financial Times and Lawrence Soloman:  A report on the change of heart by some journalists on the subject, based in part on the Economist’s stance. 

Is it Really 4,000?

Here is an introduction to the rest of this post. 

Have you heard that 4,000 scientists from 130 countries support the IPCC’s conclusions about climate change? According to Energy Probe the “consensus” is not as it seems. The work of “2,500+ scientific expert reviewers, 800+ contributing authors, 450+ lead authors from 100+ countries” is not really that. The numbers total 3,750, which is rounded up to 4,000. By elimination of duplications, exaggerations, and input not relevant to the result, Energy Probe whittles down the list of true backers of the IPCC report to approximately 60.

Read the articles and decide for yourself.