carbon dioxide vs global temperature graph

 
Local and global weather has always fluctuated and always will, so global warming cannot be expected to be a smooth process. But what can be seen above is that half of all man-made CO₂ has been put into the air since 1975, and that matches the one-degree F global temperature increase since 1975 rather well.

This is not proof of that the CO₂ caused the warming. But, if CO₂ did not cause it, we have a somewhat unusual coincidence. As seen on the temperature page this thirty-year temperature increase is unusual. There was only one temperature swing of this size in the oldest thermometer record which dates back 350 years, and it was a down swing. Upswings of this magnitude would seem to happen only about once in 700 years, and this one happened right in step with human CO₂ production. 

The slight downward trend in temperature from about 1945 until about 1975 is due to the increase in Sulfate Aerosols (SO₄), largely produced by burning coal that contains sulfur. These cool the earth, and their increase during these years largely canceled the increase in CO₂ during the same period.