Impulse-Response Climate Models

As an example of an impulse-response climate model, we consider in the following the response of the climate system to CO2 emissions e t) (cf. Fig, 3), which represent about 60% of the total greenhouse warming today and are expected to contribute a still larger fraction in the future. For small perturbations, the relation between the CO2 forcing and the climate-change response i/r(x, f) can be expressed as a linear response integral... 

FIGURE 9 Evolution of the atmospheric CO concentration and the global mean temperature, computed with the impulse-response climate model of Hot)SS cf al. (2000), for a BAU scenario and a frozen-emissions scenario F over the next 100 years (upper panels) and the next 1000 years (lower panels). The long-term climate change in the lower right panel is seen to greatly exceed the predicted climate change in the next 100 years (indicated also by boxes in the lower panels). 

The linear impulse-response model has recently been generalized by Hooss et al. (2001) to include some of the dominant non-linearities of the climate system. The net response curves shown in Fig. 5 were computed using this generalized model, showing the impact of nonlinearities in the lower two-panel rows. The princi-... 

Hooss, G., Voss, R., Hasselmann, K., Maier-Reimer, E., and Joos, F. (2001). A nonlinear impulse response model of the coupled carbon cycle-ocean-atmosphere climate system. Clim. Dyn. (in press). 

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