" There is conflicting evidence on this. It is not a firmly established fact that global tempetures have increased in the past century"
What do you consider to be "firmly established"? What is proven is that isotherms have, and are, shifting northwards in many areas in North America, Europe and the oceans. This affects the ecological mix in a given area, the flora in particular changes. This is well documented in Great Britain, they have very good records going back a couple of centuries. You have to remember that usable thermometers with some degree of repeatability only date back to the 18th century and they weren't really accurate until the late 19th/early 20th.
Now in this century, average night time temperatures have increased, day time temperatures are, as you say, mixed. This is significant, it is precisely what you would expect due to greenhouse gasses. I will try to did out those issues of "Nature" where this is tracked. It is interesting.
"So because of dimly understood and conflicting evidence you want to take actions that will cost trillions of dollars?"
By the time it is indisputably proven that global warming is occuring due to human input, it'll be too damn late. As I have stated before, there are very large sinks of potential greenhouse gasses that will dump to the atmosphere if warmed too much. Check out this link on methane hydrates
marine.usgs.gov
The trillions of dollars is something to be disputed. There are some offsetting things that can be done, i.e. encouraging planting of trees, alternates to slash and burn in tropical regions and possible iron enrichment in polar oceans. Certain tax breaks for alternate energy sources like fuel cells and solar panels would help. Like with our current budget surplus, you have to first decrease the rate of increase.
A journey of a thousand miles starts with a single step. We are still in the house, arguing over whether or not "outside" has been firmly established as existing... |
