RE: Studies prove link between human activity and extreme weather events
zackers, #19
You think the claim that "man caused global warming" is an assumption but there is plenty of evidence to back it up.
If there were no greenhouse gases (natural or human produced) in the atmosphere the average temperature on the surface of the Earth would about 0 degrees Fahrenheit instead of about 58 F. This is well established science. The most important GHG's are water vapor, CO2 and methane. Clouds are also a major factor.
The level of CO2 in the atmosphere has risen from about 280 ppmv in 1830 to about 390 ppmv in 2010, a nearly 40% increase, after being about 280 ppmv for the last 10,000 years. The year to year rise of atmospheric CO2 is 40-50% of the total amount of CO2 released by human activities. That is powerful evidence that the rise in CO2 is due to humans. There is other evidence such as the ratio of C12/C13 that point to human burning of fossil fuels for the CO2 increase.
In the absence of changes in other known factors that affect climate those two things are powerful evidence that most of the global warming is due to human activities or feedbacks from those activities. The evidence is strong enough now and has been studied for long enough that you need to present some actual science that refutes it. Just saying we don't know enough to say is not good enough.
The papers weren't addressing whether the warming came from humans or not but how temperature changes have affected precipitation patterns.
If you want to read the paper your nearest university library should be able to get a copy of the Journal it was published in for you. Sometimes it takes a little effort to find a paper published in a Journal but it's doable if you want it.
