On 12th November, the US and China announced a historic bilateral agreement to reduce greenhouse gas (GHG) emissions amounting to a 26-28% reduction by 2025 (from a 2005 base) for the US and a peak in emissions in 2030 at the latest for China. Whilst the implications for the Paris Summit in 2015 seem positive, there are still question marks over how the US and China will actually achieve these new targets, or indeed, if they can be seen as achievements in the first place.

For the US, these new targets have unfortunately coincided with the Republican Party being elected to take control of both houses of Congress in 2015.

Given the Party’s traditional resistance to climate change legislation, President Obama may find himself in a protracted struggle to make good on his promises – a luxury which the two remaining years of his Presidency do not afford him.

Ultimately too, whilst the agreement with China is classified in the US as a pollution measure and hence determined by Executive Action, Congress is still able to scrutinise all budgets and could easily stall any emissions cutbacks until President Obama’s term has ended.

To some extent, the Obama Administration has already taken steps to reduce future emissions with the US Environmental Protection Agency (EPA) this summer calling for power plants to cut CO2 emissions by 30% by 2030 from a 2005 base.

On the other hand, given how high US emissions (table above) have been in the last two decades, and long before (see World Resource Institute for more information here), one of the biggest questions that still hangs over the US and Western economies in general is whether historical emissions should be accounted for when setting reduction targets.

For developing countries, it has long been a bone of contention that industrialised nations who have historically been the biggest cause of climate change should attempt to establish a deal that does not include this at the expense of their own economies’ industrialisation through ‘traditional’ means.

For a long time, one of the key arguments made alongside the historical emissions debate was that the US and China, the world’s two largest polluters (table top right), had made no progress so there was no reason for other nations to take the initiative as any action would have been marginal by comparison.

Given that China, was, and still is, part of the push for historical emissions, its commitments are arguably all the more important as an marker to others that, despite differences, a deal in Paris still has potential.

Moreover of course, China is the world’s largest consumer of coal and, according to the Global Carbon Project, was responsible for 28% of global GHG emissions in 2013 (with the US at 14%), a rise from 2012-2013 of 4.2% in the country’s emissions.

As such, whilst the ambiguity of “by at least 2030” is frustrating, the burden for action seems to weigh much more heavily on China. Given its prodigious fossil fuel growth, even with 24% of the world’s renewable energy capacity according to this year’s Global Status Report, the importance of this target cannot be overstated.