If global warming and Carbon Dioxide, and thirty years?

Question

If global warming and carbon dioxide are directly related to each other, then why, in the thirty year period between 1940 to 1970, did the global temperature go down?

Answer 1

The temperature didn't actually go down, the warming leveled off.

The analyses here are not simple and there were multiple reasons.  Man was putting a lot of particulate matter (dust) into the air.  That slowed down a lot after 1970 under the new Clean Air Act.  Solar activity was down a bit.  And the really big greenhouse gas emissions had not started.

This graph shows what happened, why it happened, and why things are warming fast now.  It's based on extensive peer reviewed data.

http://www.globalwarmingart.com/wiki/Ima...

Climatologists look carefully at all this stuff.  Honest.  And the vast majority are convinced that the present warming is serious and mostly caused by us.

http://www.sciencemag.org/cgi/content/fu...

Answer 2

Statistical noise. The answers above look very well on paper but they're not proveable.

As a matter of fact we're told that the average global temps are up a couple degrees in a century. That's really quite a meaningless statistic because the margin of error of that estimate is greater than a couple of degrees.

Answer 3

It was primarily in the 1940's that temperatures fell, thereafter the trend started rising again.

The reason was sulphur dioxide in the air.  Prior to the 1950's there were no Clean Air Acts and the atmosphere was the most polluted it's ever been, particularly with vast quanities of SO2 emitted from power stations, industry, coal burning and coal gas.

SO2 reflects sunlight back into space which is why in the aftermath of major volcanic eruptions the global temperatures fall - as happened following the 1991 eruption of Mount Pinatubo.

The pollution crisis reached a climax following the deaths of many thousands of Londoners from a blanket of pollution that enveloped the city in 1952.  Thereafter laws were passed requiring dramatic reductions in pollution emitted into the atmosphere (particularly SO2).  As SO2 levels fell the temperatures began to rise again.  It's ironic that by cleaning up the atmopshere we've contributed to global warming.