The COP26 conference hosted by the UK later this year is the world’s "last, best opportunity to get real" on the climate, according to US envoy John Kerry.
Speaking at a World Bank event to promote climate solutions and support developing countries transition to a low carbon future, he said almost no nation in the world is meeting its targets to tackle climate change.
In the run-up to November’s COP26 summit hosted by the UK in Glasgow, Mr Kerry called on countries to step up their ambition on reducing emissions.
The climate envoy said: "Science is coming back at us stronger, harder, bigger, faster. It’s essential we raise ambition.
"We make Glasgow the next step in divining not what we’re willing to do but what we really need to do in order to be able to get the job done."
The Duke of Cambridge also spoke at the event about the importance of COP26.
In a video message, Prince William called the conference a "vital step" on the path to putting nature "centre stage" in tackling the climate crisis.
He said: "The decisions that leaders take in Glasgow will echo down the generations for years to come. So let’s make it count.
"Protecting and restoring nature is critical to the success of COP26 in Glasgow later this year and for the brighter, greener more prosperous future that we all want to see.
"We cannot recover sustainably from coronavirus, eradicate global poverty, achieve net zero emissions or adapt to climate change without investing in nature."
The world needs a 45% reduction in emissions over the next 10 years to limit global warming to 1.5 degrees above pre-industrial levels but is not currently on track to meet the goals set out in the Paris Agreement in 2015.
Donald Trump pulled America out of the agreement when he was president.
Having now re-joined it, Joe Biden is soon expected to announce America’s plans on emissions cuts – what’s known as its NDC – or Nationally Determined Contribution.
The COP26 president Alok Sharma told the discussions that the world is a long way off meeting the Paris goals.
And he urged the World Bank to step up support to countries transitioning away from fossil fuels.
He said: "Action is essential. A key goal of the UK’s COP26 presidency is building up international collaboration particularly around clean power, clean transport and nature and getting finance flowing particularly to developing countries.
"All governments need to develop ambitious adaptation plans and emissions reduction targets and place them at the heart of national investment strategies. We must act now and seize the opportunities presented by green recovery."
Sky News has this week launched the first daily prime time news show dedicated to climate change.
Hosted by Anna Jones, The Daily Climate Show is following Sky News correspondents as they investigate how global warming is changing our landscape and how we all live our lives.
The show will also highlight solutions to the crisis and show how small changes can make a big difference.