Pathways to a low carbon world

I keep reading alot about different emissions targets and people who say its too much / not enough ... so I decided to have a look myself.

I think the best parameter to look at is CO2 emissions per person & try and figure out what will have to happen in order to achieve temperature stabilization at a safe level (which most people accept is around 2degC).

Using UN population forecasts to 2050 (at which time we are expected to have a planet of 9 billion people) and data from the IPCC reports on emissions reduction requirements for stabilization I came up with the following graph (the pathway for 3degC is from the Stern report, the other 2 pathways are my interpolation ... the shape may be slightly off, but the endpoints are correct!).



We need to move from a world where the average person emits 6.8 tCO2/year to one in 2050 in which they emit around 2 tCO2/year, in order to get to anywhere near a 2degC stabilization point.

Here is another graph showing current emissions levels. The 2 black bars indicate 2020 and 2050 required targets for stabilization at 2.2 degC



The average UK person currently 10tCO2/year. So the "60% reduction by 2050" UK Goverment target only brings that to 4tCO2/year (assuming a constant UK population ... which is reasonable) ... they need to be talking about 80% reduction unless they want other countries to emit less to compensate (which I don't think can be argued to be fair).

However, some environmentalists, such as George Monbiot, Johnathon Poritt and Mayer Hillman are talking about a 90% cut in UK emissions by 2030. They propose moving onto a "war footing" in order to get this done. 1tCO2/year by 2030, looks to be extreme. A 2.2degC stabilization path (the extreme given in the IPCC report), means we could still emit 4tCO2/year in 2030. I think people like Monbiot forget that we don't have the technology now that we will have in the future - its unreasonable for us to be expected to move to that long term target of 1tCO2/year too soon. We need to allow technology time to develop, and its not going to happen overnight - although it needs to happen quickly. That said, I think we need people like Monbiot to balance people like GM CEO Bob Lutz.

Seems to me that a hybrid of the 2 schemes ... 60% reduction in emissions by the year 2030 would be best for the UK. This would be a path to long term stabilization at 2.2 degC. What is important to remember though, is that it is not what the UK does, but what the world does.

The main tool for getting this done ... a global, realistic (at least $50/tCO2) )price on Carbon emissions and quickly.