Several thousand climate scientists throughout the world have been researching the global warming issue since the 1980s. They have produced detailed reports on the scientific evidence and reasons for concern about global warming. These findings have been accepted by an overwhelming majority of climate experts and other scientists throughout the world.

However, some scientists, business people and politicians are sceptical that global warming is a threat to humanity and question whether humans have contributed to it. Some scepticism is based on scientific reasoning, some is due to misunderstandings about climate science, and some is driven by self interest.