Projections of Future Changes in Climate

The more complicated models limits the number of length of simulations that can be performed on them. This is especially important when addressing the uncertainty associated with with any climate model.

In order to standardize the assumptions made in prediction studies the IPCC publish a range of emissions known as SRES (Special Report on Emission Studies) that attempt tp describe different ways the world might develop in terms of population growth, economic growth, technological development etc.

The scenarios include the world as one where

• A Economic growth prevails
• B Climate concerns prevail
• 1 Globalization increases
• 2 Regional differences are preserved.

Global Mean Temperature Changes

Under a B1 scenario the temperature is likely to rise by 1.8C relative to 1980-99 period. Under an A2 scenario a 3.6C warming is predicted

Geographical Pattern of Temperature Changes

The pattern is for warming everywhere. 8C in the Artic to 1C in the Antartic and nothen Atlantic

Geographical Pattern of Precipitation Changes

Some regions are predicted to get drier while other wetter but some of the models disagree. Equatorial regions are likely to get wetter amd sub-tropical areas to get drier. Substantial drying is predicted in central Europe all the way up the the UK and dwon to north Africa.

Continental Temperature Change Projections (and attribution to natural and anthropogenic forcings)

The figure shows green bands indicating changes due to natural forcings separated from the orange bands that show anthropogenic forcings. The lack of warmings in the green bands shows that warming is almost entirely attributable to human activity

Projections of Global Sea Rises

Under the selected scenarios the sea will rise between 40cm and 50cm by the end of the century due to thermal expansion and ice-pack melt. If a greater number of uncertainties are included the rise is as much as 70cm. Finally when all uncertainties are included the range inclreases to 90cm

Conclusion

The collective models point to a much warmer world by the end of the century especially in the Artic and inclusing the sea. This gives rise to increased sea levels. However, precipitation is much harder to predict although it seems likely their will be wetter winters in northern latitudes.

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