The year 2020 could be a tipping point for emissions - so Trump needs to see sense very soon

Christiana Figueres, the feisty Costa Rican diplomat who shepherded the historic 2015 Paris climate change agreement, this week launched the Mission 2020 campaign that aims to put greenhouse gas emissions on a downward curve by the end of the decade.

Climatologists involved in the campaign have identified 2020 as a tipping point beyond which global warming could become unstoppable.

"If emissions do not begin their rapid decline by 2020, the world's most vulnerable people will suffer even more from the devastating impacts of climate change," said Figueres, who headed the United Nations climate secretariat.

The intervention is timely. The election of Donald Trump as president in the United States - the second-largest global polluter - has given comfort to climate skeptics and heralded a revival of fossil fuels.

In late March, Trump issued an executive order rolling back former president Barack Obama's Clean Power Plan, which had required the adoption of more renewable and low-emission energy.

And this week, the failure of ministers of the G7 group of industrialized countries meeting in Italy to issue a climate change statement was blamed on the fact that the US was still "reviewing" its policy.

With the threat of the US pulling out of the 197-nation Paris climate pact, it has fallen to China and Europe to assume leadership on an issue that scientists say is the greatest challenge facing humanity. The White House is due to announce by the end of May whether it will withdraw from the multilateral agreement.

Miguel Arias Canete, the European Union's climate action commissioner, criticized Trump's rollback of US emissions rules, saying last month that "the continued leadership of the EU, China and many other major economies is now more important than ever".

While China remains the world's largest greenhouse gas emitter - a consequence of its rapid economic development - the authorities have already taken steps to cut the country's reliance on coal, announcing just this week that China will gradually reduce the planned power output of existing coal-fired generating plants.

The country's leaders have also pledged adherence to the Paris agreement, described by President Xi Jinping in a speech at the Davos World Economic Forum in January as "a hard-won achievement".

"All signatories should stick to it instead of walking away from it, as this is a responsibility we must assume for future generations," Xi said.

Last month, Chinese Foreign Ministry spokesman Lu Kang reacted to Trump's assault on Obama's Clean Power Plan by saying all countries should "move with the times".

"No matter how other countries' policies on climate change, as a responsible large developing country, China's resolve, aims and policy moves in dealing with climate change will not change," he said.

US climatologist Michael E. Mann wrote this week that China's policies were in part responsible for putting the world on the right course in combating climate change.

"Global carbon emissions have plateaued and are projected to remain flat over the coming years, thanks to China's widespread economic transformation and the global boom in renewable energy production," the Penn State University professor wrote in Time magazine. "The 2020 climate turning point is within reach."

The consensus appears to be that action on global warming will accelerate, regardless of the stance adopted by the White House. In fact, the US could lose out to competitors such as China and Europe if Trump fails to grasp the benefits of green energy.

China leads the world in renewable energy investment and is set to dominate the market in future decades. Some experts believe China's move away from coal will depress its global price, damaging those US coal-mining communities Trump says he is pledged to help.

As Christiana Figueres noted this week: "This is no longer about ideology, it's about sheer economics."

The author is a senior media consultant for China Daily UK. Contact the writer at editor@mail.chinadailyuk.com