What is the evidence that climate change is occurring?

Answer 1

The evidence is now so overwhelming that climate scientists are no longer in doubt that global warming and climate change are occurring, and that this is the result of human activity. But even opponents of climate science are beginning to accept the facts of global warming.

A team of physicists and statisticians set out to challenge the scientific consensus on global warming but is finding that its data-crunching effort is producing results nearly identical to those underlying the prevailing view. The Berkeley Earth Surface Temperature project at the University of California, Berkeley, was launched by a Physics Professor, Richard Muller, a longtime critic of government-led climate studies, to address what he called "the legitimate concerns" of sceptics who believe global warming is exaggerated.

But Professor Muller unexpectedly told a congressional hearing that the work of the three principal groups that have analysed the temperature trends underlying climate science is "excellent ... We see a global warming trend that is very similar to that previously reported by the other groups." Although not a climatologist, Professor Muller had the professional training to identify problems in climate data, and was supported by a professional team of of physicists and statisticians, yet he was unable to find any serious flwas in the work of those whom he had formerly criticised. The evidence is in, and has passed the most serious scrutiny.