The world is warming at a rate faster that has ever been observed in the past. Overwhelmingly scientists are of the opinion that this is largely due to the effect of gases released into the atmosphere by human activities. How can we be sure that this is the case? Does it matter? What can we say about the future?

This talk will look at the scientific evidence for climate change in the context of natural variations and it will discuss how increasing concentrations of “greenhouse gases” (GHGs), especially carbon dioxide, create an imbalance in the Earth’s energy budget with impacts on temperature, sea level and weather patterns.

We will see how basic physics can be used to construct the computer models which are employed to investigate climate processes and look at potential future impacts across the world of increasing GHGs. We will go on to consider what needs to be done to reduce GHG emissions in order for the world to avoid dangerous levels of warming, and where we are heading following the United Nations climate change agreements.