Old Rocks
Diamond Member
The warming started ...
The warming? This is one of the fundamental things I don't understand about the discussion. Why can't there be more than one reason that there is warming? Obviously there are natural mechanisms and cycles. On the other hand, I haven't seen anyone say that (if it exists) man made climate change some how turns them off. As we start solar cycle #24, will the sun have an effect on the atmosphere? Sure. Does that somehow prove that human-produced CO2 is having no effect? Surely not.
Gremlin, there are many factors that can influence the climate, and the amount of warming or cooling of the whole globe.
However, most of them have been ruled out.
Solar influence. The sun has had a slight decrease in Total Solar Irradiance over the last fifty years. That should have resulted in a very slight cooling. 2008 represented a long solar low, with hardly any sunspots at all. At the same time, we had a strong and persistant La Nina. We should have had a very cold year, one that should have at least been in the lower one quarter of the warm years. Instead, 2008 was either the eighth or tenth warmest on record.
By the Milankovic Cycles, we should be slowly descending into another ice age. In fact, the last 2000 years saw a gradual cooling trend until the last 150 years. Then, as we burned fossil fuels, and increased the GHGs in the atmosphere, it has began to warm.
If you wish to really research the subject, here is a site from the American Institute of Physics that traces the history of the investigations of GHGs;
The Carbon Dioxide Greenhouse Effect