Failure to act now could mean the Amazon rainforest is devastated; large sections of the global community go short of food and water; many heavily populated low-lying coastal areas are flooded and insect-borne diseases such as malaria spread across the world.
The report from the UK Meteorological Office’s Hadley Centre, predicts that, by the 2080s, if action is not taken to tackle climate change:
- global temperatures will rise by about 3 degrees C
- large parts of northern South America and central southern Africa could lose their tropical forests
- around 3 billion people could suffer increased water stress; Northern Africa, the Middle East and the Indian subcontinent will be worst affected
- around 80 million extra people could be flooded each year due to rising sea levels: Southern Asia, South East Asia and island states in the Caribbean, the Indian Ocean and the Pacific Ocean will be most at risk
- about 290 million extra people could be at risk of malaria – China and central Asia will be most affected
- the risk of hunger in Africa will increase due to reduced cereal yields
However, compared with the predictions above, the report concludes that if carbon dioxide in the atmosphere was stabilised at 550ppm the worst impacts of climate change can be avoided or delayed by up to 100 years. This would provide valuable time for society and the environment to adapt and:
- delay a 2 degrees C global temperature rise by over 100 years
- avoid significant losses to the Amazon rainforest and delay loss of the carbon sink by 100 years
- cut by 2 billion the number of people experiencing increased water stress by the 2080s
- delay a 50cm sea-level rise by 55 years and reduce by 75 million the number of people experiencing annual flooding from rising sea-levels by the 2080s
Climate scenarios for the study were evaluated by the second Hadley Centre Coupled Ocean Atmosphere Climate Model, HadCM2. For each of the three emissions scenarios, predictions of surface temperature, precipitation, sea level rise and ocean circulation were made. These predictions were then used to make assessments of the global impacts in the following areas: natural vegetation; water resources; world food supply; sea level rise and human health.