–Since you have testified to Congress at the request of Republicans in the past, and since Jim is in a powerful position, do you feel some sense of obligation towards correcting Jiim’s views?–
There is no evidence that humans have caused global climate change, nor is there evidence that human are likely to have caused much of increase in global temperature in last century.
What one could call a global climate change is the Sahara Desert going from a wetter conditions to drier condition that it is today. There have been various ideas that do blame human activity for this climate change, but the evidence seems to indicate that this change in climate was natural variability in climate rather than something caused by human activity.
One could also point to the dust bowl in the US in 1930’s as example of an minor global climate change. One can make a case that human activity worsen the effect of this natural climate change, but you can’t argue [successfully] that the drought conditions were caused by human activity.
One also point to many decadic changes in regional climates, and these are also a result of natural variability.
Humans using irritation have transform regions- turning deserts into farmable regions- one can assume this climate change, but this is incorrect as one has not actually changed global climate. Likewise urban area can cause rainfall shadow- likewise this only has small regional effect and is not global climate change.
And changes in global climate which result century periods of warming and cooling are not caused by human activity.
So idea of human causing global climates changes is only a idea of what might happen in the future and is not something which has happened in the past- though have changed local conditions. Cut down trees, irritated dry [or desert] regions, built dams, built cities, and etc is not global climate change.
