Why I Don't Trust the IPCC

I was reading a new climate blog hosted by Nature Magazine. One of the early entries is about examination of the Hockey Stick. The International Panel on Climate Change (IPCC) is in the process of releasing their fourth assessment report. The Hockey Stick was the center piece of their third report.

I started studying history, especially 17th century history, in detail in the 1980s and I was rather surprised to find out how variable climate has been. The world was in a warm state a thousand years ago. Starting around 1400, a long-term cooling period began. Known as the Little Ice Age, it lasted into the middle of the 19th century.

This is one reason that I have always been very skeptical about global warming. It isn't proving much to say that the world is the warmest now that it has been in the last 600 years if most of that period was colder than normal. It is like becoming alarmed because July is so much hotter than the previous six months.

Then the IPCC released their 3rd assessment report with the Hockey Stick. According to the new figuring, the Little Ice Age was just a localized phenomena limited to the northern Atlantic. When considered on a global perspective, it faded into the background. According to the new figures, the world's climate was amazingly stable until industry ramped up in the mid-19th century. After that, the world's temperature rose like the blade on a hockey stick.

Global warming was proved by the Hockey Stick. The IPCC was so impressed with their new graph that they featured it on the cover of their report and even on their letter head.

But people started questioning the hockey stick. Where had it come from and how did it go from obscurity to icon in a few months? Who did the peer review on it? What about conflicting evidence?

For a time these questions had to be asked quietly because no one would publish them. Finally the dam broke and the detractors had their say.

It turned out that the hockey stick was basically someone's doctoral thesis (specifically Michael Mann). It was never given a vigorous peer review. It was simply adopted.

The IPCC has stopped using the hockey stick as a symbol. Their newest assessment now uses a blended temperature chart.

The IPCC gains some of their credibility from their association with the UN but most of it comes from its reputation as a gathering of scientists interested in truth. The sad truth is that they are just people. While scientific method is supposed to provide a buffer to keep personal opinion from coloring results, it has to be applied.

When Mann presented his temperature reconstruction to the IPCC, they were so enchanted by the results that they didn't stop to check it. They needed it to be true and it confirmed their prior beliefs so they gave it a cursory check and made it their centerpiece.

This leads to the big question - how often have they done the same thing with other studies? How often have they accepted work that verified their mission or rejected something at odds with their pre-defined results?

The thing about trust is that once you know it has been abused, you are less likely to trust again. That's my position on the IPCC.