Climate Change: Evidence and Causes

Climate change is one of the defining issues of our time. It is now more certain than ever, based on many lines of evidence, that humans are changing Earth’s climate. The atmosphere and oceans have warmed, accompanied by sea-level rise, a strong decline in Arctic sea ice, and other climate-related changes.

The evidence is clear. However, due to the nature of science, not every single detail is ever totally settled or completely certain. Nor has every pertinent question yet been answered. Scientific evidence continues to be gathered around the world, and assumptions and findings about climate change are continually analysed and tested. Some areas of active debate and ongoing research include the link between ocean heat content and the rate ofwarming, estimates of how much warming to expect in the future, and the connections between climate change and extreme weather events.

The Royal Society and the US National Academy of Sciences, with their similar missions to promote the use of science to benefit society and to inform critical policy debates, offer this new publication as a key reference document for decision makers, policy makers, educators, and other individuals seeking authoritative answers about the current state of climate-change science. Questions addressed include:

• If the world is warming, why are some winters and summers still very cold?
• What are scientists doing to address key uncertainties in our understanding of the climate system?

The Report can be downloaded from The Royal Society website page and is also available here.

Queries, and requests for printed copies, can be directed to: sally.tyldesley@royalsociety.org