Boris Johnson will tell a summit of world leaders that 2021 must be the year countries “get serious” about stopping climate change.
The virtual summit is considered another waypoint ahead of the UN Cop26 talks in Glasgow in November.
Today’s summit has been convened by US President Joe Biden who is expected to pledge to at least halve US greenhouse gas emissions by 2030 on 2005 levels.
UK targets 78% cut in emissions
Ahead of the event, Mr Johnson announced a “world-leading” target for the UK to cut emissions by 78% on 1990 levels by 2035.
The UK’s new target builds on its plan to cut emissions by 68% on 1990 levels by 2030, the most ambitious among leading economies.
But campaigners have warned that policies and action are urgently needed to deliver on the pledges and cut pollution from homes, transport, industry and power supplies.
The PM is expected to tell the meeting: “The UK has shown that it’s possible to slash emissions while growing the economy, which makes the question of reaching net zero not so much technical as political.
“If we actually want to stop climate change, then this must be the year in which we get serious about doing so.
“Because the 2020s will be remembered either as the decade in which world leaders united to turn the tide, or as a failure.”
He will urge leaders to come to Glasgow in November – and Kunming in China in October for a summit on tackling declines in nature – armed with ambitious targets and the plans required to reach them.
He will add: “Let the history books show that it was this generation of leaders that possessed the will to preserve our planet for generations to come.”
His call comes after the International Energy Agency warned that global carbon emissions were set for their second biggest increase on record after a sharp drop in 2020 due to the pandemic, with demand for fossil fuels, including coal, pushing climate pollution up to close to 2019 levels.
40 world leaders invited to virtual summit
The two-day US-led summit will also hear from leaders of major economies including China, Japan, Russia, Canada, India and Australia, who will be watched closely to see what ambition they will bring to the table.
Japan and Canada are among the countries expected to unveil new climate targets at the meeting, while the European Union has agreed a new climate law which includes a goal to cut its emissions by 55% by 2030 on 1990 levels.
As part of diplomatic efforts in the lead up to the summit, the US and China issued a statement pledging to work together and with other countries on the issue.
For the US, Mr Biden is expected to set out a pledge to cut emissions by at least 50% on 2005 levels by 2030, nearly double the nation’s previous commitment, as he seeks to encourage other countries to boost their efforts.
The proposal – estimated to be around a 41% cut on 1990 levels – is part of the US’s national climate plan, which it is submitting as part of its return to the Paris climate accord, the world’s first comprehensive climate treaty which Donald Trump quit when he was president.
Countries have been expected to come forward with more ambitious plans up to 2030, known as nationally determined contributions (NDC) in the Paris deal, ahead of Cop26 in November.
That is because existing plans are not enough to meet countries’ commitments under the Paris deal to curb global temperature rises to “well below” 2C above pre-industrial levels – or 1.5C if possible – and avoid the most dangerous impacts of climate change.
The summit, which will have sessions on increasing climate action, finance for developing countries, the role of natural solutions such as restoring forests and peatlands, and security impacts of climate change, will also hear from United Nations Secretary General Antonio Guterres and Pope Francis.
Jennifer Morgan, executive director of Greenpeace International, said history had to be made at the summit.
“True climate leadership requires laws and regulations to phase out fossil fuels, end deforestation, and restore nature. Our survival depends on real climate action.
“To get closer to the 1.5 pathway, significant political will and action are required,” she urged.