Physical feedbacks, climate

Climate is often viewed as the aggregate of all of the elements of weather, with quantitative definitions being purely physical. However, because of couplings of carbon dioxide and many other atmospheric species to both physical climate and to the biosphere, the stability of the climate system depends in principle on the nature of feedbacks involving the biosphere. For example, the notion that sulfate particles originating from the oxidation of dimethylsulfide emitted by marine phytoplankton can affect the albedo (reflectivity) of clouds (Charlson et ai, 1987). At this point these feedbacks are mostly unidentified, and poorly quantified. 

The nature of such processes can be depicted as a feedback loop, as shown in Fig. 17-4. Using the nomenclature in this figure and continuing with enhanced evaporation of water vapor as our physical example of a feedback that is completely internal to the climate system, we... 

We have already posed the hypothesis based on Fig. 1-2 that climate is stabilized by negative feedbacks. The known and proposed feedbacks are listed below, starting with the purely physical examples, which are the simplest and best... 

The radiative forcing depends on the concentration change and the absorption characteristics of the atmospheric constituents both are reasonably known. Therefore, uncertainties associated with model calculated radiative forcing are much smaller than the climate feedbacks, which involve complex interactions between dynamics, physics and chemistry of the climate system. Because changes in 03 affect the Earth s climate, and changes in climate and circulation affect the 03 layer (cf. Wang et al., 1996), the development of a coupled climate-chemistry model system is needed to quantify the effect of changes in atmospheric 03. 

To improve understanding of the physical processes and feedbacks through which the cryosphere interacts within the climate system. 

Schlesinger, M. E. (1988). Quantitative analysis of feedbacks in climate model simulations of CO,-induced warming. In Physically-ba.sed modelling and simulation of climate and climate change, part 2. (M. E. Schlesinger, Ed.), pp. 653-735. NATO ASI Series. 

The question is now how to physically force Psw to follow the degassing. The answer lies in the fact that the chemical weathering of continental silicates appears to be dependent on air temperature, the dissolution being enhanced during warmer climates. This dependence provides a negative feedback that... 

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