Scientific American:

"Despite Climategate, IPPC Mostly Underestimates Climate Change
Speaking at the annual meeting of the American Association for the Advancement of Science, James McCarthy of the Harvard Medical School Center for Health and the Global Environment noted that the IPCC usually errs on the conservative side. Steve Mirsky reports



Lost in the coverage of the so-called climategate email controversy is a key point about the IPCC's track record of climate change estimates. James McCarthy is on the faculty of the Harvard Medical School Center for Health and the Global Environment. He spoke February 21st at the annual meeting of the American Association for the Advancement of Science in San Diego:

"If you were to go back and map the IPCC projection for sea level rise and temperature in 1990, look at it in 1995, look at it in 2000. In retrospect you would find that they were conservative. So we talk about errors. If you were to do two ledgers—here are IPCC overestimates, here are IPCC underestimates—over the 20 or so years that these assessments have been running, the underestimate ledger would be much larger than the overestimate. Even with glitches—clearly erroneous editing or sloppy editing that led to these erroneous statements that got us in trouble recently.""