Warmer than the IPCC

© 2002 Eugene S. Takle

Knutti et al (2002) use a somewhat simplified climate model together with a Monte Carlo procedure to produce probabalistic climate projections. Their anthropogenic radiative forcing is 1.4-2.4 W m-2 for the 5% - 95% confidence range, with 0 to 1.2 W m-2 (cooling) being attributable to effects of sulfates. In their approach, the observed warming of the ocean and atmosphere of the last few decades provides a strong constraint on the magnitudes of future warming in the near term. They find that there is a 40% chance that warming over the next century will exceed the IPCC estimates and only a 5% chance that warming will fall below the IPCC range.

Reference

Knutti, R., T. F. Stocker, F. Joos, and G.-K. Plattner, 2002: Constraints on radiative forcing and future climate change from observations and climate model ensembles. Nature, 416, 719-723.