Wednesday, July 11, 2012

A thought about global warming

No one year's events, much less a single event such as the direcho of described in the video can be clearly related to global warming. However, there is clearly an increase in the average global temperature:

Source: SEED
It is also the case that average temperatures have changed naturally over geological time:

Source: SEED
It is well known that greenhouse gases in the atmosphere contribute to warming of the earth's surface. In fact without those gasses that have been emitted naturally, the world would be hardly livable. We know that in addition to carbon dioxide there are other greenhouse gases, and we know that due to human activity there are lots of greenhouse gases being emitted and that the concentration of greenhouse gasses is increasing in the atmosphere.

Source: SĂ©mhur via Wikipedia
There remain some uncertainties. Models of climate change differ in their predictions. Natural climate change and climate change due to the actions of man by be confounded. Still, there is very widespread agreement among experts that:
  • humans are contributing substantially to global warming;
  • that there will be a significant increase in average global temperatures over at least the rest of the century;
  • that the increases will not be uniform over the globe, but that some areas will be more affected than others;
  • that there will be more and more severe adverse weather events as a result of global warming;
  • that there will be other effects such as sea level rises, changes in climate zones, and changes in ecology.
The oil company executive in the video is correct that people are going to have to adapt to changes. It is too late already to reverse changes that are in progress.

Many, including me, agree to a precautionary principle -- that we should do what we can to reduce the rate mankind is spewing greenhouse gases into the atmosphere so as not to do more damage than is necessary. It is also agreed that we should prepare to deal with adverse events and trends resulting from global warming. 

Many of us believe that poor people in poor countries are likely to suffer most from the effects of global warming, and that it is rich people in rich countries that are responsible for a very disproportionate level of greenhouse gas emissions. It would seem that those who contribute more to the problem should help those who suffer most from the problem.

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