6/04/2007

Climate Change "Consensus"

Lawrence Solomon, Executive Director of the Urban Renaissance Institute, has written a series of newspaper articles for a Canadian paper, the National Post. The series was called "The Deniers," and offered profiles of various scientists who disagreed with the climate change models foisted on us by the media.

Something funny happened on the way to the forum:

Somewhere along the way, I stopped believing that a scientific consensus exists on climate change. Certainly there is no consensus at the very top echelons of scientists -- the ranks from which I have been drawing my subjects -- and certainly there is no consensus among astrophysicists and other solar scientists, several of whom I have profiled. If anything, the majority view among these subsets of the scientific community may run in the opposite direction. Not only do most of my interviewees either discount or disparage the conventional wisdom as represented by the IPCC, many say their peers generally consider it to have little or no credibility. In one case, a top scientist told me that, to his knowledge, no respected scientist in his field accepts the IPCC position.

What of the one claim that we hear over and over again, that 2,000 or 2,500 of the world's top scientists endorse the IPCC position? I asked the IPCC for their names, to gauge their views. "The 2,500 or so scientists you are referring to are reviewers from countries all over the world," the IPCC Secretariat responded. "The list with their names and contacts will be attached to future IPCC publications, which will hopefully be on-line in the second half of 2007."

An IPCC reviewer does not assess the IPCC's comprehensive findings. He might only review one small part of one study that later becomes one small input to the published IPCC report. Far from endorsing the IPCC reports, some reviewers, offended at what they considered a sham review process, have demanded that the IPCC remove their names from the list of reviewers. One even threatened legal action when the IPCC refused.

1 comment:

JC said...

There are a couple of ways you can approach the global warming debate. You could have a scientist roll call to see which side looks the most impressive. On the one hand, you have a scattering of scientists as presented in the National Post series. On the other side, you have the IPCC saying man causes global warming. Or if the IPCC is not your cup of tea, there's always the Academies of Science from 19 countries endorsing the IPCC's position both here and here. Or NASA's Goddard Institute of Space Studies, the National Oceanic and Atmospheric Administration, Environmental Protection Agency, American Geophysical Union, American Institute of Physics, National Center for Atmospheric Research and American Meteorological Society.

However, roll calls don't really interest me. It's more relevant to examine peer reviewed journals - scientists can have their theories but they need to back it up with empirical evidence and research that survives the peer review process. A survey of all peer reviewed abstracts on the subject "global climate change" published between 1993 and 2003 show that not a single paper rejected the consensus position that global warming is man caused. 75% of the papers agreed with the consensus position while 25% made no comment either way (eg - focused on methods or paleoclimate analysis).

Personally, I like to examine each argument on a case by case basis. Here's the arguments used in the National Post series that try to explain global warming without CO2:

Part 1: "The hockey stick was debunked due to statistical errors." Since the initial hockey stick study by Mann and its subsequent "debunking", there's been around a dozen proxy studies, analysing a variety of different sources including corals, stalagmites, tree rings, boreholes, ice cores, etc. The results all confirm the same general conclusion: the 20th century is the warmest of the entire record, and that warming was most dramatic after 1920. This is even confirmed by Stephen McIntyre, one of the original hockey stick debunkers.

Part 6: "Less cosmic rays => less clouds => global warming." The big flaw in the cosmic ray theory is cosmic radiation has shown no trend over the last 50 years. So even if cosmic rays are linked to cloud formation, all they'll find is the cloud formation 50 years ago is the same as it is now and has little to no impact on global warming today.

Part 9: Mars is warming. The whole theory that a brightening sun is causing global warming falls apart when you consider solar output hasn't risen over the last few decades of global warming according to direct satellite measurements that found solar output has shown no rising trend since 1978, sunspot numbers which have leveled out since 1950, the Max Planck Institute reconstruction that shows irradience has been steady since 1940 and solar radio flux or flare activity which shows no rising trend over the past 30 years. So what's causing warming on Mars? The planet has had massive darkening storms over the last 30 years that reduce the planet's albedo (reflectivity) which warms the planet.

Part 10 rehashes Part 6 and 9, blaming the sun and cosmic rays. Again, solar activity and cosmic radiation have shown no long term trend over the same period global warming has been greatest. If there is a "smoking gun" in global warming, solar variations sure ain't it.