In his regular column, the BBC's environment analyst, Roger Harrabin, draws on his experience of a quarter of a century reporting the environment to assess the impact of last week's G20 meeting on the ongoing UN climate negotiations.
CLEAN ENERGY - SHOULD RICH NATIONS SUBSIDISE THE POOR?
North African countries have much to gain from solar power
The trouble with being an environment minister is that many of the levers of environment policy rest in the hands of politicians in other departments.
And what was top priority for climate negotiators seeking political support from world leaders meeting at the G20 last week was not necessarily top priority for the leaders themselves.
So it is that decisions left un-taken in Pittsburgh have resounded to rattle the UN climate talks starting this week in Bangkok.
The issue in question is how much cash will be given to help developing countries obtain clean energy supplies.
Previous major climate negotiations have focused on emissions cuts by rich nations. But the need to tie developing countries into a climate deal means that the issue of financing is much more important than before.
The International Energy Agency says more than 90% of the new energy infrastructure over the next few decades will be in the developing world.
Gordon Brown says $100 billion dollars a year is needed to tackle poverty through clean energy by 2020 and the EU more or less agrees. Some developing countries think the figure should be half as much again.
But at the G20 meeting President Obama skirted the issue. His climate policies face potentially insuperable opposition in the US Senate. So now energy funding will be referred back to the G20 finance ministers meeting in November.
This is getting very late - and compounds the difficulties of the climate negotiators who are desperate to start trimming some of the hundreds of brackets from the text of the Copenhagen deal.
It's another example of politics lagging behind the science. A new projection from the UK's Met Office suggests that unless emissions are cut urgently, global temperatures could rise 4C by the middle of the century, maybe 15C in the Arctic.
Whether you have faith in climate models or not, it's clear that politics as we know it can't yet respond to the urgency of the defined risk.
If Gordon Brown can get President Obama to share a glass of mulled wine in Copenhagen this December, things might look a look more optimistic. But Todd Stern, the chief US climate negotiator who helped negotiate the Kyoto Protocol under President Clinton, told me that the US would not repeat the mistake of signing a climate deal that wouldn't get through Congress.
The President has been widely condemned by developing countries for his failure to commit funds. But the timing is dreadfully difficult. The Waxman-Markey Bill which passed through the House of Representatives allowed for trading of emissions permits. That would supply cash for developing countries - billions a year, Stern told me - but how many billions we can't say until the final deal is agreed. Even then the numbers will depend on the carbon price.
President Obama did adopt one initiative in Pittsburgh that will help the environment. He called for an end to subsidies to fossil fuels. As the Oxford academic Norman Myers pointed out in his 2001 book, the world is spending trillions a year subsidising the very pollution it is theoretically trying to expunge.
In many countries the subsidies to the fossil fuel industry - though tax breaks, incentives and failure to pay for "externalities" like polluting the atmosphere - add up to way more than subsidies for the clean energy systems which political leaders prefer to talk about.
The trouble is that it's easy to give a subsidy to a big polluting industry - but very hard to take it away without facing a barrage of lobbying. In the US this is compounded by donations by big firms to underpin the election campaigns of Senators and Representatives.
That's why the president said the subsidies should be phased out in the "medium term". China will be looking closely at this initiative. Coal is still subsidised there.
It might help if more people knew about the "block tariff" policy invented by Bangladesh. Low users of electricity can buy power very cheaply in order to encourage parents to install light bulbs to educate their children. But the price per kWh increases in blocks, so the rich in mansions on the edge of Dhaka end up paying high prices for their air conditioning and fridge freezers. This is the sort of social innovation politicians need more of if they want to tackle the problems of climate change and development.