I turn my attention to the main GHG emitter of the world, who is single-handedly responsible for one third of all cumulative CO2 emissions since 1850, the United States. Although in terms of annual emissions China has now overtaken the US (both are coasting around the 6 billion metric tonnes of CO2 emitted per annum), China's cumulative emissions since 1850 are less than 8%.

It can also be argued that the US as main importer of Chinese goods is running a huge bill in terms of indirect emissions, in addition to its own direct emissions, and therefore is party to China's annual emissions. Taking into account indirect emissions from the consumption of manufactured goods would put the US very comfortably on the top position of net emitter per annum as well as in cumulative terms. The US imports about one third of China's manufacturing output (followed by the EU and Japan, as close second and third net importers -according to figures of the CRS Report for Congress "China's trade with the US and the world" 2007) and therefore its indirect emissions are in the region of 1/3 of China's annual emissions, that is about 2 billion tonnes of CO2 - that gives the US a grand total of annual emissions (direct plus indirect) in the region of 8 billion tons of CO2 p.a.

The new US administration is certainly diametrically opposed to the previous one, but on emission cuts it is still guaranteed to fall short of expectations.

The news is that Obama will pledge to cut CO2 emissions by 17%, which is already considered by the EU "lower than we would like", but even that level of cuts might be immensely tricky to the US president to turn into law, overcoming all the hurdles of the US legislative complexities.

The EU is pledging to cut emissions by 20-30% by 2020 (compared to 1990 levels). That means that annual emissions would drop from today's 4.3 billion tons to somewhere between 3 to 3.4 billion. The US's pledge by contrast would mean a drop from today's 6 billion to 5 billion.

As a ballpark figure, our atmosphere is receiving more than double the amount of CO2 than it can process through its natural carbon cycle. In order for us to stabilitise the CO2 concentration therefore all countries need to cut emissions as a matter of urgency by 50%, at least. Given that developing countries do not have ambitious targets, if at all, the US and EU need to have aspire to more drastic cuts.

If all countries cut their emissions by 50%, this would mean that the US annual emissions should drop from 6 billion tons to 3 billion, and the EU's from 4.2 to 2.1 billion. The EU pledge of cutting emissions to the 3-3.4 billion level leaves us with an excess of 0.9-1.3 billion with respect to what should be the target reduction, and the US pledge leaves us with an excess of 2 billion tons. This means that between the US and the EU an excess CO2 of over 3 billion tons of CO2 will be emitted per annum between now and 2020 (even if the pledges they advocate where carried out right now, rather than gradually between now and 2020).

Brunella