THE DOUBLING of carbon emissions from the burning of fossil fuels has caused global warming ranging from 0.5°C to 1.5°C.

Oceans have warmed more slowly than the land. Polar icecaps have not melted, as forecast in the 20th century, but sea levels have risen by up to 20cm as the warmer oceans expanded, flooding the swathes of the Florida Everglades and much of the Ganges delta in Bangladesh.

Deserts have encroached on arable areas. In Siberia and Canada uninhabited areas have become fertile but, because the permafrost melts, they are often too wet to grow crops.

Another 10% of the world's forests may be lost within 20 years. Nearly all African and Chinese forests will disappear at the hands of logging companies. With water becoming more scarce, domestic and industrial users are required to recycle. Sources of clean energy, such as fusion reactors and hydrogen-fuelled motor systems, are ever more essential. SC