Climate Change – The Impacts
As promised in my first article, this month I will cover the impacts of climate change. What are they? When might they happen? Should we be seriously worried?
The answer to the last question is a resounding yes. Already in this country we are getting more frequent extremes of weather and know how damaging they can be: the floods this year and drought last year are just two examples. Other countries are suffered much worse: this year for example there have been forest fires in California, Greece, Australia; devastating floods in other countries. The average global temperature is currently 0.76 deg above the pre-industrial level, and is very likely to rise to 2 deg above (I’ll explain why in a later article). So these extremes will get far worse.
The melting of Arctic floating ice has been well reported. This year the permanent sea ice shrank to 1.6 m (million) sq miles. The previous lowest was 2.05 m in 2005. Ice is melting far faster than forecast. This is scary because it means that other predictions are probably optimistic too, sea level in particular. Rising temperatures are also melting the Greenland ice cap. If the entire Greenland ice cap melts, this will increase sea level by 7 m and flood all the world’s coastal cities. Up to this year, it was thought that this will take place over a few hundred years. However scientists now say there is a risk that we could see a rise of 3 to 4 m this century.
Glaciers and the snow caps of mountain are retreating worldwide. In many regions the regular winter build-up of snow followed by summer melt governs the fresh water supply, so loss of snow and ice will cause drought in summer, floods in winter. The food and water supply in SE Asia and South America will be worst hit, leading to worldwide food shortages.
Other impacts include the spread of deserts, die-back of forests, spread of tropical pests and diseases, the threat to marine life from a combination of rising temperatures and rising acidity, species loss, large numbers of environmental refugees. The risk of conflict over scarce resources will increase.
A major international conference in 2005 concluded that a global temperature rise of between 1 and 2 deg will put 1.5 bn at risk of water shortage (present world population is 6 bn): this might occur between 2030 and 2050. A rise of between 2 and 3 deg will put 5.5 bn at risk of hunger): this might occur between 2050 and 2070. These alarming numbers led to EU countries agreeing to try to limit the global temperature rise to 2 deg.
So the risks are enormous here: the future of our children is at stake. That is why we must limit the global temperature rise and we have to start now. The emissions reductions needed will be in next month’s article.