Climate commitment: Difference between revisions

Revision as of 05:09, 24 April 2005

Revision as of 05:15, 24 April 2005

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== Basic idea ==

If a [[perturbation]] - such as an increase in [[greenhouse gas]]es or [[solar activity]] - is applied to the [[climate system]] the response will not be immediate, principally because of the large [[heat capacity]] of the [[ocean]]s.

:''As an analogue, consider the heating of a thick metal block by the sun, or by a flame: the block will warm, more or less slowly, until the entire block has reached [[equilibrium]] with the imposed heating. If a thin plate is heated instead, the plate will warm far more quickly because of its lower heat capacity. ''

Land only stores [[heat]] in the top few meters.

The oceans, by contrast, are vertically mobile ([[convection]]) and store heat within their depth ([[convection]]).

This is why the land surface is observed to warm more than the oceans. <!-- is this really needed: "and it is predicted that this should continue in the future."--> It also explains the very large difference in response between

* "equilibrium" climate prediction [[Execution (computers)|runs]] in which only a shallow ocean is used and it is assumed that the climate has come to equilibrium. and

* "[[transient]]" climate prediction runs (in which a full ocean is used) and the climate is out of balance,.

and

"[[transient]]" climate prediction runs (in which a full ocean is used) and the climate is out of balance,

== Models ==