Later in the session, when we are studying the Atmosphere section of the course, we will be looking at the issue of climate change - in particular global warming. We will look at some of the causes - physical and human - for the current rise in global temperatures. News footage on the 6 o'clock news this evening and an article on the BBC website reveal a vicious circle of cause and effect. It appears that the Siberian permafrost is melting (photo above shows permafrost exposed on a riverbank) and as the soil thaws out, it is releasing vast quantities of methane into the atmosphere. As methane is a greenhouse gas - and a very powerful one at that - this will further enhance the greenhouse effect and so cause global temperatures to rise even further.
The news report can be viewed by clicking on the video and audio news panel when you link to the BBC website page.
