| Climate Change |
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Human induced climate change – which results from increased ‘greenhouse’ gases (GHGs) in the atmosphere – is the greatest social, economic and environmental threat of this century. It’s a problem mankind has caused mainly through our rapid exploitation of fossil fuels, and it’s a problem we need to solve with our collective intelligence, creativity, and humanity.
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 “The scientific evidence is now overwhelming: climate change presents very serious global risks, and it demands an urgent global response”
Stern Review Report on the economics of climate change, HM Treasury, UK Government 2006 |
The greenhouse effect - some basics
The earth’s atmosphere, like our own bodies, cools or warms until the energy ‘inputs’ (radiation from the sun) are in balance with energy lost through cooling. Certain gases in the atmosphere (called Greenhouse Gases or GHGs) ) act like feathers in a duvet – they trap and hold heat in the atmosphere and influence the temperature at which the global atmosphere is in balance. The more GHGs in the atmosphere, the higher the global temperature (the more feathers in a duvet, the warmer it is).
The root cause of climate change?
The principle GHG is carbon dioxide (CO2). Over billions of years, organic matter from dead plants and animals transformed into coal, oil, and natural gas in the outer layers of the earth’s crust. Since 1750, mankind has extracted these fossil fuels, and used them to power our rapid industrial development. Carbon dioxide from the combustion of fossil fuels accounts for about two thirds of the human induced warming effect. Methane, nitrous oxide and other gases emitted from industrial and agricultural activities account for the remaining third.
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CO2 concentrations in the atmosphere have risen one third since the industrial revolution and are set to double in the next 100 years. Temperatures which have varied less than 1 degree Celsius since the dawn of civilisation, are projected to rise between 2 and 4 degrees Celsius over the next century. This is a very rapid transformation in comparison to the longer-term warming and cooling cycles naturally experienced over past millennia. Scientists predict that such rapid changes will cause major and severe harm to the social, economic and environmental systems upon which mankind depends for its sustained survival.
“Global atmospheric concentrations of carbon dioxide, methane and nitrous oxide have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values….”
Intergovernmental Panel on Climate Change; Climate Change 2007: The Physical Science Basis: Summary for Policymakers), February 2007; www.ipcc.ch. |
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The impact of climate change?
SwissRe (www.swissre.com) , the global reinsurance company, provides an economic impact indicator: losses from natural disasters are doubling approximately every 10 years and could reach about $150 billion in 10 years. In a study of the summer of 1995 in England and Wales, which was about 1.5C warmer than average, it was estimated that net economic losses were about £1.5billion.
The consensus from the 2005 Conference of Scientific Experts (Exeter, UK; http://www.stabilisation2005.com/) was that a temperature increase of 2 degrees Celsius above pre-industrial levels may trigger melting of the Greenland ice cap. To have a high probability of not exceeding this 2 degree Celsius limit, atmospheric CO2 concentrations should stay below 400ppm. This threshold could be breached in 10-15 years at the current rate of increase in global emissions.
Those least able to cope with climate change – developing countries – are likely to be among the most affected. It will further reduce access to drinking water, negatively affect the health of those living in poverty, and will pose a real threat to food security in many countries. If the Greenland ice sheets melts, the sea level rise would be so dramatic that the map of the world would change substantially.
“The impacts of climate change are not evenly distributed – the poorest countries and people will suffer earliest and most. And if and when the damages appear it will be too late to reverse the process. Thus we are forced to look a long way ahead.”
Stern Review Report on the economics of climate change, HM Treasury, UK Government, 2006, www.hm-treasury.gov.uk
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Browse our site for further inforrmation on CO2 emissions and carbon offsetting
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