Climate change has been the subject of debate for the longest time. Two such experts who are debating are Kevin Trenberth from the National Center for Atmospheric Research, who believes that humans are to blame behind climate change, and Judith Curry from the Georgia Institute of Technology, who firmly holds that humans have no influence on the matter.

Writing in the WIREs Climate Change, Trenberth said that the evidence for man-made climate change is now so clear that the burden of proof should lie with research, which he said seeks to disprove human's role.

Trenberth expressed that there is no doubt whatsoever that humans are changing the climate. He stressed that the only question is the extent of human's contribution to the problem.

Looking at how scientists' efforts on the topic, Trenberth said that they should challenge misconceptions and to include human as a component in their studies.

Responding to what Trenberth had said, Curry argued that that there should rather be a debate over the significance of man-made warming relative to forced and unforced natural climate variability. Curry went on to say that putting the fault on humans would reverse the scientific focus and funding.

She added that she doubts that Trenberth's suggestion will have much support in the scientific community, saying that there is still a lot to prove when it comes to humanity's involvement in climate change such as did human's influence on climate increase the risk of the whole event? And did human action increase it by more than a factor of two?

Scientists and experts note that human's part on climate change is the emissions that are produced from cars, buildings, and facilities which contribute to the overall greenhouse effect, while on the other hand, others are still skeptical that humans have any impact on the matter.