Climate change could cost economy trillions

American economists have warned that the repair bill if we fail to address climate change could run into trillions of dollars whilst the social and environmental costs will be incalculable.

This is the verdict of a report from the Global Development and Environment Institute

at Tufts University which surveyed hundreds of environmental and economic academic papers which looked at the effects of allowing the global temperature to rise to two degrees above pre-industrial levels.

The findings are in stark contrast to those of a report released by energy giant Shell last week (related story) which claimed climate change could boost the British economy by £30 billion over the next decade as industry makes the most of new technologies and the opportunities presented by new regulations.

The American report, however, paints a less positive picture, looking at the likely climatic effects of allowing the mercury to creep up the global thermometer and the cost of having to deal with increasingly frequent and sever extreme weather events.

It estimates that annual economic damages could reach US$20 trillion by 2100, equivalent to 6% to 8% of global economic output at that time and points out that this calculation does not it does not include the cost of biodiversity loss, unpredictable extreme weather or the collapse of Gulf Stream.

So far global temperatures have increased by 0.6 degrees on pre-industrial levels and a business as usual model suggest that by 2100 that figure could reach four degrees.

At two degrees above pre-industrial levels, says the report, we can look forward to decreased crop yields in the developing world, widespread drought and water shortages, a near total loss of coral reefs, extinction of arctic species and the spread northwards of tropical diseases such as malaria.

Another degree beyond that and it predicts that crop yields will also plummet in the developed world, increased desertification, the complete collapse of the Amazon ecosystem, those of many other forests and alpine regions, wider spread of an increasing number of diseases and species extinctions will become commonplace.

The doomsday scenario for a four degree increase would see the western Antarctic ice sheet melt, increasing see levels by five to six metres turning millions of people around the world into environmental refugees as they flee coastal and low lying areas. In some areas agriculture would become completely inviable due to water shortages and soil erosion.

Allowing the temperatures to creep above the four degree increase would be catastrophic, says the report, and there would be a roughly 50% chance that the ocean’s circulation system would

shut down, removing the crucial currents that warm and stabilize the climate of Northern Europe.

Dr Frank Ackerman, director of the research and policy programme at the Global Development and the Environment Institute and one of the authors of the report, said: “The climate system has enormous momentum, as does the economic system that emits so much carbon dioxide. Like a

supertanker, which has to turn off its engines 25 km before it comes to a stop, we have to start turning off greenhouse gas emissions now in order to avoid catastrophe in decades to come.”

Elizabeth Bast from Friends of the Earth US said:”This report demonstrates that climate change will not only be an environmental and social disaster: it will also be an economic catastrophe, especially if global temperatures are allowed to increase by more than 2 degrees centigrade.”

According to Dr Ackerman, comparatively small amounts of money are required to this economic and ecologically catastrophic supertanker, with carbon-cutting measures in the USA alone likely to save US$12 trillion a year at a cost of US$3 trillion a year.

Sam Bond

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