The Details
While often expressed in dry language, the science is actually very frightening, and the predictions are getting worse
fast. The Copenhagen Synthesis Report, prepared this March in preparation for the Copenhagen meeting in December, is very readable, and RealClimate.org has a page of links which is a good start point if you wish to explore the science.
The problem is not trivial. Over 80% of our energy sources emit large amounts of CO2. Agriculture and other human activity emit methane and other minor greenhouse gases. These have warmed the planet by about 0.7 degree C above preindustrial levels with another 0.6 degree rise inevitable due to thermal inertia. Both emissions and temperature have been increasing rapidly since the 1970′s as a result of increased consumption and population growth, as well as the reduction in smog which had a cooling effect. Warming causes a number of secondary feedbacks, most of which will cause additional rapid warming. Both computer models and historical records show that these will become significant once warming has reached 2 degrees in total, and that the danger of a runaway climate increases rapidly after that.
The problem is urgent. The consensus is that CO2 should not be allowed to rise past 400 parts per million (ppm). 450ppm brings a 50% chance of over 2 degrees warming and many are now calling for stabilization at 350ppm. This is a problem as we are already at 390ppm and growing at an accelerating 2.3ppm per year. We need to stop most if not all coal, oil and gas or somehow remove the CO2 they cause from the atmosphere. This needs start now, our emissions must peak within 5 years, and we need to be mostly finished in 30 years. A recent study
looking at emissions from a different point of view confirms this. It calculates that we have historically emitted about 500 billion tonnes of carbon (not CO2) and that total future emissions of 500 billion tonnes gives a 50-50 chance of avoiding more than 2 degree warming. On current trends we will do this within 40 years. Halving the future emissions to 250 billion tonnes leaves a 25% chance of exceeding 2 degrees. Current annual emissions are just over 8 billion tonnes of carbon (30 Gt CO2) and still growing fast.
2004 Statistics show that Coal provides about 25% of our total energy use, with Oil at 35% and Gas at 20%. Nuclear is 6.5% and renewables 13%. Unfortunately the 13% is very misleading as 10.5% is from burning wood etc in developing countries, 2% is from hydroelectric and only 0.5% is what we tend to think of as renewables. So to put it mildly we need a major change. There has not been a lot of detailed work done on what is needed, as most governments have assumed that putting a price on carbon will encourage industry to do the rest. Slow action and the massive giveaways to existing industry are likely to distort this process, and indeed this has already happened in Europe, the only region which has made a concerted attempt at reducing emissions. Nature has published a study by Joseph Romm which builds on work at Princeton University describing “stabilization wedges” each of which starts today at zero and builds up to a reduction of 1 billion tonnes of carbon emissions over the next 30-50 years. He goes into more detail here showing that we need 12- 14 wedges to stabilise atmospheric carbon dioxide levels.
While this requires an enormous change to the way we generate energy, it is certainly possible, and promises some major advantages. We waste about half of the energy we extract, which will not only make the job easier, but save some cash along the way. McKinsey showed in 2008 that improving efficiency saves serious money, and Romm believes that efficiency can provide 3 of the wedges. There is widespread agreement that we have all the technologies that are necessary – we just need to get off our collective backsides and do something other than talk about it. One of the likely major energy sources is Solar Thermal (3 wedges) which has been in use in California for 20 years, can store heat to supply electricity at night or on cloudy days, and is ideally suited to Australian conditions.
There is even a neglected IFR nuclear reactor design which was used for 20 years, and seems to solve many of the waste and risk problems of the current reactors. However the longer we do nothing the more likely it is that we will be forced to make panic cuts which damage our living standards, probably just when most of us are becoming most vulnerable (and venerable).
Any major change creates opportunities for businesses and countries that get in on the ground floor, especially as the new energy industry would be roughly an order of magnitude the size of the computer industry. Bill Gates times ten, anyone? In the previous major industrial revolutions, it has been the new and not the existing companies that become the leaders, making it foolish of our government to throw money at current industry.
This report from the CSIRO is an overview of likely effects on Australia. Appendix B details the likely changes for a selection of cities by 2030 and 2070. Under the IPCC’s A1Fl scenario (Their most extreme projection which is similar to current trends) we have a 50% change of summer temperatures 3.1 degrees hotter and a 10% chance of 4.7 degrees by 2070, and the number of days over 35 degrees will at least double, with a 10% chance of trebling. Note that this report was based on the IPCC AR4 and the science has got a lot worse since then.
