Chris de Freitas: Emotion clouding underlying science of global warming
nzherald.co.nz 5 January 2010
Unlike most other hot button environmental issues, global warming is widely misunderstood. As a climate scientist thinking about this, it struck me that it was not surprising since accounts of the scientific basics of global warming almost never appear anywhere in the press.
There is not space here to include all the charts and numbers that might accompany such an account. In its place is a necessarily brief summary.
Most people are not shocked to learn that global warming discussions evoke polarised views, but many are surprised to discover that the scientific basics are not contentious. An awareness of these is helpful in building an understanding of the extent to which there is a problem and how it might be addressed.
On average, heat gained by the Earth from energy received from the Sun is equal to heat lost to space. Greenhouse gases in the atmosphere, mostly water vapour, carbon dioxide and methane, regulate this heat loss.
Global warming theory says that mankind's burning of fossil fuels such as oil and coal, adds to the carbon dioxide concentration in the atmosphere, which controls how fast the Earth looses energy to space.
More carbon dioxide causes warming in the lower atmosphere until Earth-to-space energy balance is once again restored.
The degree of warming directly caused by the extra carbon dioxide is, by itself, relatively small. This is not controversial. What is controversial is whether this initial change will trigger further climate changes that would be large or damaging.
Read the full article at:
http://www.nzherald.co.nz/opinion/news/article.cfm?c_id=466&objectid=10697845
