Most remarkably, the total amount of CFCs, ozone-depleting molecules that are well-known greenhouse gases, has decreased around 2000,” Lu said. “Correspondingly, the global surface temperature has also dropped. In striking contrast, the CO2 level has kept rising since 1850 and now is at its largest growth rate.”
In his research, Lu discovers that while there was global warming from 1950 to 2000, there has been global cooling since 2002. The cooling trend will continue for the next 50 years, according to his new research observations.
As well, there is no solid evidence that the global warming from 1950 to 2000 was due to CO2. Instead, Lu notes, it was probably due to CFCs conspiring with cosmic rays. And from 1850 to 1950, the recorded CO2 level increased significantly because of the industrial revolution, while the global temperature kept nearly constant or only rose by about 0.1 C.
Lots of debate at that second link.