As evidence has mounted and expert warnings have grown ever more urgent, denial of climate change (or humans’ role in it) has become a badge of honour – even a litmus test – for significant parts of the political right. And so, as the world’s climate diplomats gathered in Bangkok last week for the latest round of United Nations talks, United States delegate Jonathan Pershing felt it necessary to explain to his counterparts that Congress is a coequal branch of government, independent of the Obama administration.

Well may he have warned them. The previous week, congressional Republicans had reportedly called ‘an economist, a lawyer and a professor of marketing’ to debunk the climate threat and the need for government action in testimony. These political divisions are an obvious constraint on the US’s position in the talks and therefore on the scope of the entire negotiation.

At the UN talks, the key fault line is not between right and left but between developed and developing countries. It is a difficult divide to bridge, and negotiations at Bangkok were brought to a standstill because of it.

On Tuesday night, the G77 and China bloc of developing countries rejected the draft agenda for talks to agree a global climate framework as too narrow. A competing G77 draft agenda was rejected by the US and other wealthy nations as unfocused and for ‘re-litigating’ the Cancun Agreements of last December.

Chief European Union negotiator Artur Runge-Metzger blamed the ‘agenda fight’ on a combination of countries who mistakenly thought the rich world was trying to impose a bottom-up, ‘pledge-and-review system’ of national commitments as an ‘end of the road’ outcome, countries ‘who think that the Cancun Agreements were a step too far, and maybe we need to try to rewind the clock’, and ‘some who do not have any kind of interest in international climate negotiations who are just putting little spanners into the wheels’.

Informal consultations resulted in a compromise agenda being adopted after 8pm on Friday night. Of course, the meeting soon adjourned and the new agenda will next be formally considered in June.

Progress also proved elusive in talks to determine the future of the Kyoto Protocol, the first period of which expires at the end of 2012. With the UN warning that a gap is becoming inevitable, parties were at odds over whether political commitment to a second period should precede discussion of rules and technical issues. Tuvalu’s negotiator went so far as to ask nations who were not interested in a second Kyoto period to ‘leave the room so that we can have a focused discussion’, drawing applause.

Bill Hare, the Potsdam Institute scientist and former Intergovernmental Panel on Climate Change lead author, criticised the ongoing argument over whether rules or political commitment to a second Kyoto period should come first as ‘fairly arid’. It’s ‘a bit like an alcoholic who’s stopped drinking and then has another one, [promising] “I will stop tomorrow”‘, Hare said, adding that in reality both ‘outcomes are mutually negotiated’.

Among the major economies, the EU occupies an increasingly lonely position on the Kyoto Protocol. The EU is ‘open’ to commitments under a second Kyoto period subject to certain conditions, which include major emerging economies making a ‘comparable effort’ within a ‘legal framework’ outside Kyoto. Japan, Russia and the US all reiterated their intention not to make Kyoto commitments post-2012.

While the major economies made no new emission reduction commitments in Bangkok, some clarifications made at a pre-sessional workshop had the effect of making the EU’s existing target more ambitious, according to this Climate Action Tracker paper. But a week dominated by an agenda fight will give no one confidence that an effective global climate deal is in prospect.