Global warming The steady rise in global average temperature in recent decades, which experts believe is largely caused by man - made greenhouse gas emissions. (bbc.com)
According to the published report, there is no longer a discrepancy in the rate of global average temperature increase for the surface compared with higher levels in the atmosphere. (realclimate.org)
It is not news to climate scientists that natural variability impacts the short - term movement of global average temperatures in both directions. (skepticalscience.com)