America’s special climate change envoy John Kerry has met Prime Boris Johnson and senior UK ministers in London.
Their talks come ahead of two critical summits – one in the US in April and the other in Glasgow in November.
Leaders are wrestling with gloomy news from China, whose recent five-year plan takes tiny steps to decarbonisation.
But they will be heartened by President Biden’s $1.9 trillion stimulus package agreed by the Senate, which will support “green” economic growth.
There is positive news too, from Brazil, which – under US pressure – says its previous stance blocking climate talks was misunderstood.
Mr Kerry, a former US Secretary of State appointed to the role by Mr Biden in November, spent several hours in Downing Street with Alok Sharma, the cabinet minister who is chairing November’s COP26 summit.
He tweeted afterwards that they had also been joined by Mr Johnson.
Mr Kerry was also due to meet other senior UK figures, including Chancellor Rishi Sunak, Foreign Secretary Dominic Raab, and Business Secretary Kwasi Kwarteng.
On Tuesday, climate diplomacy sees him in Paris and Brussels for talks with European leaders, who have been praised for their recent target to cut emissions 55% on 1990 levels.
Monday’s meetings may go some way to helping the UK focus its objectives for the November gathering.
Ministers were accused recently by MPs on the Business and Energy Select Committee of failing to set clear goals.
The committee said the key areas identified by the UK for action – adaptation and resilience; nature based solutions; energy transitions; clean transport and switching the finance system to low-carbon investments – were too broad and “without clear measures for success”.
It said more focus needed to be given to the “overriding necessity” of agreeing deliverable policies that keep global temperature rises to as close to 1.5C as possible.
Nick Mabey, from the think tank e3g, told the BBC there was the potential to achieve multiple goals – including banning new coal power plants, ending banks’ fossil fuel investment and supporting poorer nations to adapt – and that these should be debated publicly.
“This debate is up for grabs” he said. “It should be a public debate because we’re talking out how to change whole economies. A lot of the outcomes from Glasgow will be decided in the court of public opinion.”
John Kerry’s meetings with the UK politicians who will be running the COP26 summit may help bring some much-needed clarity to efforts on this side of the Atlantic.
But he will also be assessing just how much political capital Team Biden should invest in Team Boris.
So far, the messaging from the UK on what COP26 can realistically achieve has been muddled. If every country is going to put a new climate plan on the table before Glasgow, what’s the actual point of the meeting?
Mr Kerry will also be assessing how much diplomatic heavy lifting he should undertake on behalf of the Brits.
To give Glasgow a chance, both India and China will have to come up with significant advances on their current actions on carbon.
Others, including the Saudis and the Brazilians, will have to show flexibility. Kerry’s involvement may be critical in delivering these outcomes.
But his impression of the British effort will also influence events back home. President Biden is organising a climate summit of world leaders for 22 April.
That meeting may become the bigger focus for the US if Kerry takes a dim view of UK’s efforts on the COP.
Critics say the UK government must also focus on its own performance before attempting to lead the world in the November summit.
Another group of MPs on the Public Accounts Committee recently complained that two years after declaring a target of near zero emissions by 2050, the government still had no plan to achieve that.
A government spokeswoman said: “It is nonsense to say the government does not have a plan when we have been leading the world in tackling climate change, cutting emissions by almost 44% since 1990 and doing so faster than any other developed nation in recent years.”
The government’s critics point out that the UK was able to cut emissions swiftly from 1990 because coal-fired power stations were at the end of their lives at that time.
Since coal has been almost completely closed down, UK emissions cuts in many areas have almost stalled.
Follow Roger on Twitter @rharrabin