Relative to the 1979 baseline, the tropics have expanded poleward 56km to 111km per decade in each hemisphere. If this rate continues then we may witness an expansion of 850km by 2100. This is roughly equivalent to the distance from Rome to London.
Expansion of the tropics has massive implications for societies, economies and the natural world as Earth’s climatic zones shift poleward. Both human and natural systems will be forced to adapt to new climatic conditions. In particular, there will be unprecedented heat for hundreds of millions of people in the tropics as global warming accelerates.
Africa has the largest tropical footprint among the continents and is, therefore, severely threatened by expanding tropics. Over 80% of the continent lies within the band 30 degrees either side of the equator. African nations will be particularly vulnerable due to their lower socioeconomic development.