Having been a Maths student at the University of Exeter for three years now, I’ve come to the conclusion that my degree (should I choose it to be) is very much biased towards studying the mathematics behind climate change. This year I’m taking two modules with that theme, and I must say I’ve enjoyed studying them both (granted, I’ve only been doing Mathematics of Climate Change for a week, but it looks good so far!). We have a lot of lecturers and researchers at Exeter who are tackling these issues in their work, and having the Met Office on our doorstep means that we get a lot of overlap with their work too. This year, Exeter are running a MOOC (which I today learned that it means “Massive Open Online Course”) all about climate change, and I thought that since I had an interest in it (and one of my lecturers was in the taster video!) I’d give it a go.
Week 1 started this week, and since I have Wednesdays off from lectures I’d sit down and work through this week’s content today. I was unsure to begin with how the course would be laid out, and was originally daunted by the fact that it looked like a lot of work to do at once, but once I sat down and got on with it, the combination of short videos and articles from external websites (namely NASA and the IPCC) helped to keep it interesting. I felt the course was introduced in a good way this week; I may be biased since I’ve already studied the climate system a bit, but the level at which the course has set off on is a good way to get those who may not have that knowledge hooked in (it was also nice that it didn’t feel like the explanations were being “dumbed down” too much). I also thought it was good to start the course off with some science of how the climate system works without jumping in feet first with “humans are ruining the planet” talk. I know some people will be taking this course as skeptics, and by getting the cold, hard science down first they may be a bit more convinced by any later arguments made for the case of human-driven climate change!
The first video started off explaining how the greenhouse effect works, and how intact our Earth’s climate isn’t much like a greenhouse at all, but instead is more like a blanket trapping the heat in (I felt slightly sorry for Tim stood there wrapped in a blanket – I suspect when it was filmed it was at a similar time where I spent my days in Exeter sat in a paddling pool in the garden drinking cider because it was too hot to do anything else!). Short-wave radiation is emitted from the Sun, which when it reaches the Earth is either reflected back into space by things in our atmosphere (i.e. aerosols or clouds) or it passes through the atmosphere and reaches the Earth’s surface. From there albedo comes into play; if the surface is of a light colour (i.e. ice sheets, deserts etc.) then it has a high albedo (high reflectivity) and the Sun’s radiation will be reflected back towards the atmosphere. If the surface is darker, like the oceans and forests, then the radiation is absorbed by the Earth, warming it. As objects warm up then they have to re-emit the heat that they have, so the Earth then emits long-wave radiation back out to the atmosphere. However (this is where the blanket comes in), greenhouse gases in the atmosphere (the main culprit being water vapour, but also carbon dioxide, methane, nitrous oxide, CFCs etc.) absorb some of this radiation and re-emit it back towards the Earth, trapping the heat inside the atmosphere and warming it up, like a blanket does!
The climate is pretty good at self-regulating itself, but with the increase in greenhouse gases in the atmosphere a series of climate feedback cycles occur. For example, if the temperature rises, the evaporation of oceans and other bodies of water increases. This then creates more water vapour in the atmosphere which in turn re-emits radiation back to the Earth which raises the temperature some more. This cycle is a positive feedback, since it leads to a greater and greater increase in temperature. This combined with other feedback loops (such as the ice-albedo feedback and radiation feedback which we also covered) effects the Earth’s climate in different ways.
That’s enough for now, I’m just hoping as term progresses I have enough time to keep on top of doing the online course as well as my other work!