On Monday the UK's Met Office Hadley Centre published the results of a major new scientific assessment of climate change. The assessment stated that, if emissions are left unchecked, temperatures would rise generally between 3 and 5 degrees Celsius this century above pre-industrial levels.

Most parties to the United Nations Framework Convention on Climate Change now meeting in Durban generally support containing the rise in global temperature to 2 degrees Celsius. And a paper published last weekend shows that industrial emissions of CO2 increased from 2009 to 2010 by 5.9%, far in excess of the average growth rates in the 1980s, 1990s and from 2000 to 2009.

These papers highlight the climate change challenge facing both developed and developing states in this final week of the Durban conference. But the chances of this challenge being successfully met in Durban are slim or none.

And it's unrealistic to expect that it would be.

Reports yesterday that the US and the BASIC group (China, India and others) are blocking a push backed by Australia, the EU and others for a second Kyoto commitment period post-2012 or any new legally-binding climate agreement should come as no surprise. To the extent any consensus exists amongst certain of those countries without Kyoto commitments – the BASIC group, for example – it's that any new emission reduction commitments are unlikely before 2020.

As the IISD has reported, China has set out numerous conditions for participating in a legally-binding, post-2020 agreement, with some support from Brazil, without of course establishing whether China itself would be bound by the agreement.

The US calls for all states, developed and developing, to shoulder emissions reduction commitments. Todd Stern, the US climate change special envoy, states that the need for all major emitters to shoulder climate commitments is clear – "just do the math", he says, even if the timelines for implementation might be different for different countries (unlike Kyoto).

Stern states that "[d]eveloping countries account for around 52% of emissions, now, and are projected to account for approximately 66% by 2030. They will produce some 97% in the growth of emissions between now and 2030."

As the latest IEA statistics on global CO2 emissions reveal, in 2009 China and the US (both without Kyoto targets) counted together for 41% of the world's emissions. Two-thirds of global emissions came from just 10 countries – with, of course, China and the US surpassing those of all the others.

Reducing emissions at the rate required – 3% per year for the remainder of the century, according to the CSIRO's Michael Raupach – so as to limit temperature rise to 2 degrees Celsius – requires action on the part of both developed and developing states.

And perhaps it is a mistake to equate action on the part of developed and developing states with an agreement to be internationally bound by emission reduction targets (like Kyoto). China, for example, in the past 20 years, has reduced its carbon intensity faster than any other major economy.

China has also approved seven pilot carbon market schemes which, it intends, will be expanded into a nationwide emissions trading scheme from 2015.

Perhaps it is also a mistake to focus on action at the national level without considering action at the sub-national level. In the US – the only signatory not to have ratified Kyoto – California (the world's eighth largest economy) will have an emissions trading scheme from 2013, and coalitions of states are identifying, evaluating and implementing ways to reduce emissions.

The Durban conference is now well into its second and final week. A 131-page amalgam of proposals (which deal with a raft of matters in addition to emission reduction targets) is to be considered by developed and developing states, against a background of worsening global economic conditions.

Developed states won't sign up at Durban to future legally-binding emissions reduction commitments. Developing states certainly won't.

Just do the math.

Clayton Utz communications are intended to provide commentary and general information. They should not be relied upon as legal advice. Formal legal advice should be sought in particular transactions or on matters of interest arising from this bulletin. Persons listed may not be admitted in all states and territories.