ENVS 2270 Lecture Notes - Lecture 4: Radiative Forcing, Ocean Acidification, Northern Hemisphere
6 Dec 2017
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Unit 4: climate projections: first step in predicting future climate is to predict future greenhouse gas emissions. Scenario construction: economic growth, technological development, population size, social and political will. Involve both qualitative storylines and quantitative interpretations: 4 scenarios made by ipcc: A1 made up of 4 other scenarios: a1c, a1g, a1b, a1t. 4. 2 the climate models: earth is divided into grid cells, grid cells try and predict what kind of an impact different factors will have on the cell. Climate models: 18 modelling centres in the world, 2(cid:1009) gcm"s are used i(cid:374) the ar(cid:1008) Large number of processes/mechanisms involved (climate is very complex!: modellers make trade-offs: Spatial and temporal resolution: we are looki(cid:374)g for (cid:862)ro(cid:271)ust(cid:374)ess(cid:863) of proje(cid:272)tio(cid:374)s (cid:894)i. e. how (cid:862)si(cid:373)ilar(cid:863) are they? (cid:895, climate models give us different climate projections. Model validation: we run the models backwards to test them, they can predict past temperatures. Here are some of the main findings from the most current (5th) ipcc report (ipcc,
