There’s been a lot of coverage in the last few days of a speech that Energy Secretary Ed Davey gave to the AVOID symposium at the Royal Society. See for instance The Huffington Post, with the full speech on the UK government site. It’s a powerful piece of rhetoric saying that we should listen to the scientists, stand up to the deniers, and work for a strong international agreement in 2015.
AVOID was a new group to me, and their web presence somewhat limited. I’ve not seen any further coverage of the symposium and what was said. They’re a research programme sponsored by DECC whose remit is to advise on how to avoid dangerous climate change, and are a joint project of the Met Office Hadley Centre, the Grantham Institute for Climate Change, the Tyndall Centre and the Walker Institute – all big hitters.
What’s on their website is worth looking at. It presents estimated trajectories for global temperature rises dependent on when emissions peak and how fast they drop with sliders so you can do your own experiments, and see how likely staying under the usual 2C rise is going to be. They say:
Current research suggests we are at a stage of damage limitation but can still avoid the worst effects of climate change projected to occur without mitigation. AVOID has shown that limiting global warming to just under 2 °C above historical levels is possible yet scientifically and technologically challenging.
What this means according to their figures is that if we peak emissions in 2016 we then need to cut them 4% year-on-year for the expected rise by 2100 to be less than 2C, or if we peak in 2020 then it has to be 5%. For reference, these are over a pre-industrial baseline, with 1990 being 0.56C over it, 2013 0.95C, and expected rises of 2C by 2044 and 4C by the 2090s in their average scenario.
Note also that “expected rise” is a middle figure, so this only gives us a 50/50 chance. For a 90% chance, we are looking at a 5% cut from 2016. In practice, they say, we may need some “negative emissions” (geoengineering or other means of getting carbon out of the atmosphere). It’s worrying to compare these dates with those of the international agreements that Davey is looking forward to: 2015, with things enforced from 2020, is the current timetable. All this is in line with reports such as Greenpeace’s Point of No Return (PDF) and the IEA, both of whom say that projects now being planned will take us over the line beyond which a 2C rise is inevitable.
Davey concluded his speech with:
In reality, those who deny climate change and demand a halt to emissions reduction and mitigation work, want us to take a huge gamble with the future of every human being on the planet, every future human being, our children and grand children, and every other living species.
That bet may already be on the table…