Week 4 University of Exeter's Climate Change MOOC began with an overview of climate modelling. There has been a lot controversy within the press with respect to accuracy of climate modelling including accusations of fiddling data, for example climate change sceptic Christopher Brooker's article Fiddling with Temperature Data is the Biggest Science Scandal Ever published in the Telegraph. However there have been counter arguments like this article in the Washington Post article No Climate Models Aren't exaggerating Global Warming . It is very challenging for the person in the street to know what believe is right. Scientist are the first to admit that predicting climate change is a complex business. If I have learnt one thing from this MOOC, is that data from a vast amount of sources e.g from proxy data to mathematical modelling is used to help with the predictions. If journalists had a greater understanding of the processes (for example taking a MOOC like this) rather than cherry picking their information they may form a less sceptic opinion.
Peter Cox says in first video for week 4 climate projection is a huge computational model. The accuracy of these models is tested by seeing if they can reproduce aspects of the past, by including factors that affected the climate including natural things, e.g. sun output volcanoes and by adding human factors such as the increase in carbon dioxide as a result of burning fossil fuels and deforestation. As a result scientists have found they can construct models that can reproduce aspects of the climate until about 1970, after that model simulations diverge, predicting a cooling climate rather than warming. However, if human factors such as the increase in carbon dioxide are put in warming is reproduced. This would seem to imply modelling helps with predictions, also how much natural phenomena has an impact of warming and how much human activity. Peter Cox says predicting what will happen in the next 100 years is the challenge, this is where there is uncertainty e.g. how much carbon dioxide will be produced by human activity? how will population change impact on this and will the way we generate energy change. Also we do not know what percentage of carbon dioxide emissions will be absorbed by oceans, trees and soil. The IPCC have used scenarios to help with these predictions e.g. differing amounts of carbon dioxide emissions and the impact on global warming.
The Intergovernmental Panel on Climate Change has stated that since the 1950s the ocean and atmosphere have warmed and there has been a reduction in snow and ice and over the last 3 decades the earth's surface has warmed. One of the drivers they have identified for climate change, is the total positive radioactive forcing leading to an uptake of energy in the climate system, caused by an increase in CO2 since 1750. It is extremely like that human activity has caused this. The IPCC says that there needs to be a reduction in the Green House Gases to counteract this. On top of this it is predicted that the complex area of climate feedbacks could more than double the amount of warming, due to the melting of snow and ice, water vapour, clouds and the carbon cycle.
So what can be done to combat the increase in global warming other than reducing the amount of anthropogenic CO2. This part requires a shift in the imagination. Mathew Watson in his article Why We'd Be Mad to Rule out climate engineering
We are better off knowing everything we can about all our options, however unpalatable, while being mindful of undermining efforts on greening our energy sector and, more than that, our own lives. Deployment of technologies at global-scale with trans-boundary effects must be a last resort.
So what is the last resort? Geoengineering - the deliberate and large-scale intervention in the Earth’s climatic system with the aim of reducing global warming There are 2 categories of geoengineering. Carbon dioxide removal e.g. creation of biochar; bioenergy with carbon capture and storage; carbon air capture to remove carbon dioxide; planting trees to offset and ocean fertilisation. The second is surface radiation management, reducing sunlight absorbed, This would be by deflecting sunlight away from the Earth, or by increasing the reflectivity (albedo) of the atmosphere or the Earth's surface, which would reduce GHGs and would address ocean acidification created by CO2.Geoengineering requires considerable consistent investment. Also radiation management can change the mean temperature but according to Jim Haywood we would not be able to control regional and trasnational temperatures and precipitation patterns, so there would sill be warming in the polar region and a cooling around the equator. And with geoengineering some parts of the planets will be winners whilst others will be losers, this is my concern will the societies of have nots lose out to the geoengineering societies of the the haves. There is also the issue that geoengineering solutions could give a false sense of security and could lead to greater anthropogenic carbon emissions as individuals think that these solutions are equivalent offsets. In addition to this there is the moral dilemma should we be messing around with the earth's climate but can we afford not too. The IPCC says we need to act now despite the opposition, even if we do not look at SRM we need to look at carbon capture.
