HKDSE Geography/M7/Climate Change

Several climatic changes will result.

Poleward Shift of Climatic Regions

All climatic regions have been shifting polewards. Vegetation belts in the Northern Hemisphere have shifted to the North, while those in the Southern Hemisphere have shifted to the South. Tropical regions extend to warm temperate; warm temperate extents to cool temperate; cool temperate extends into polar regions.

Ice Thawing

Permafrost has been thawing at a fast rate. This releases methane to further accelerate global warming by intensifying the greenhouse effect.

Glaciers, ice caps, icebergs and other large masses of ice are expected to thaw more because of the rise in average global temperature. In the polar regions, the melting of polar ice will decrease the albedo of the region, which means more radiation is absorbed, further accelerating warming in the area.

Extreme Climate

The quantity and intensity of tropical cyclones will increase.

As climatic regions change, evaporation and precipitation patterns will also be altered. There will be severe droughts in some regions and floods in others. Sea level change will also cause flooding.

El Nino conditions will lead to a decrease in fish yields along the coast of Peru and cause violent rainstorms there, where Australia and Southeast Asia suffer from severe droughts and fires.