Understanding Climate Change by Sarah Burch;Sara E. Harris;

Author:Sarah Burch;Sara E. Harris;
Language: eng
Format: epub
Publisher: University of Toronto Press

7.2.2. Earth system models of intermediate complexity

The energy balance models we described above focus on overall energy flows with large-scale averaging. Earth system models of intermediate complexity (EMICs) are a step toward representing Earth’s climate system in more detail. These models include some recognizable version of the distribution of continents and oceans on Earth, and typically include simplified representations of the large-scale circulation patterns in the atmosphere and oceans. In constructing EMICs, of which there is a huge variety,12 scientists deliberately use a lot of parameterizations to avoid the computational cost of explicitly modeling many processes.

The relatively few calculations required for EMICs allow modelers to complete many runs fairly quickly, each using slightly different, but plausible, conditions. The ensemble results of these many runs help test the importance of different components of the climate system, and help answer questions such as: what are plausible ranges for the strength of feedbacks involving vegetation? Are they amplifying or stabilizing? How much CO2 might the oceans absorb under different conditions?

Another advantage of simplicity in EMICs is that they can model the climate over long periods – say, paleoclimate conditions far into the past, or projections thousands of years into the future. Ensemble approaches that combine many different model runs allow modelers to estimate the probabilities of what might happen in the future with higher confidence – for example, what is the probable range of climate response to the melting of the Greenland ice sheet? If we stabilized the rate of human CO2 emissions today, how much additional warming might occur, and how fast?

Simplicity is also a disadvantage of EMICs. They do not yield detailed information about many processes in the climate system, nor do they achieve high spatial resolution. Despite their limitations, however, EMICs generally reproduce Earth’s basic climate patterns – such as spatial patterns of temperature and precipitation – that agree broadly with observations and with more detailed models. They can also be used to identify particular intervals of time for which more detailed modeling might be illuminating.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.