Heat’s on

Human factor

• Human greenhouse gas increase may be behind rise in temperatures in last 50 years

• Warming of the climate system is unequivocal, evident in rising average air and ocean temperatures, melting of snow and ice, rising sea levels

• Greenhouse gases would have caused more warming in recent times, partly offset by volcano dust and pollution

Projections

• Temperatures are likely to rise by 2-4.5 degree Celsius above pre-industrial levels. The “best estimate” for the rise is about 3C

• It is “very likely” that extremes such as heat waves and heavy rains will become more frequent.

• Antarctica is likely to stay too cold for widesurface melting and is expected to gain in mass due to more snow

What happens if temperature rises by...

1 degree C

• Shrinking glaciers threaten water for 50 million people

• Modest increases in cereal yields in temperate regions

• At least 300,000 people each year die from malaria, malnutrition and other climate-related diseases

• Reduction in winter mortality in higher latitudes

• 80 per cent bleaching of coral reefs, e.g. Great Barrier Reef

2 degrees C

• 5 - 10% decline in crop yield in tropical Africa

• 40 - 60 million more people exposed to malaria in Africa

• Up to 10 million more people affected by coastal flooding

... contd.