This year’s United Nations climate summit in Glasgow, Scotland must kick-start a decade of action to address the environmental crisis, U.S. climate change envoy John Kerry said on Tuesday during a visit to European Union headquarters in Brussels.

After four fractious years under former President Donald Trump, Kerry’s trip marks a new start in transatlantic relations - which Kerry and EU climate chief Frans Timmermans hope can reshape global efforts to tackle climate change.

“This is the moment. Glasgow is the last, best opportunity that we have and the best hope that the world will come together and build on Paris,” Kerry said, referring to the 2015 Paris Agreement on climate change.

“Scientists tell us this decade, 2020 to 2030, must be the decade of action,” the former U.S. Secretary of State added.

Nearly 200 countries committed under the Paris Agreement to halt the increase in global temperatures to levels that would avoid the worst impacts of climate change.

However, most large emitters are not living up to that goal.

On Tuesday, Kerry and Timmermans discussed how the United States and the EU - the world’s second and third-largest emitters of greenhouse gases - can convince other big polluters to make tougher emissions-cutting pledges in time for the U.N. summit in November.

China last week announced a five-year plan that analysts said would see its emissions rise. India, Japan, Russia and Brazil are all under pressure to commit to faster emissions cuts.

In a joint statement later on Tuesday, the United States and EU pledged to renew their alliance on fighting climate change and cooperate with global partners “to strengthen their climate ambition.”

The EU has already upgraded its pledge. The EU’s 27 member countries agreed in December to cut their net greenhouse gas emissions at least 55% by 2030, from 1990 levels.

The United States is due to announce its own pledge next month. EU officials and environmental groups are seeking a commitment from Washington to reduce emissions at least 50% this decade below 2005 levels.

“If it doesn’t start with a 5, we don’t consider that good,” an EU diplomat said of the U.S. pledge, referring to an emissions cut by 2030 against 2005 levels.

Reporting by Kate Abnett, additional reporting by Valerie Volcovici, editing by Marine Strauss, Angus MacSwan and Mark Heinrich / REUTERS