In a commentary published in the Science Journal Nature on Wednesday, experts pressed that carbon dioxide emissions must be reduced significantly, so that global temperature can be kept well under 2 degrees Celsius, which is the main goal of the Paris Climate Accord, by 2020. Otherwise we’d have to face the devastating impacts of global warming, such as deadly heatwaves and rising seas sooner than we think.

The already recorded 1 degree Celsius (1.8 degrees Fahrenheit) rise in global temperature has so far caused the melting of ice sheets that could cause the oceans to rise by a dozen meters and coral reefs to die from heat stress, jeopardizing marine wildlife and people’s lives connected to it. After rising for decades, global emissions of carbon dioxide driven by the burning of fossil fuels have leveled off during the last two years at about 41 billion tonnes per year.

According to the commentary signed by former US climate chief Christina Figures, There is a long way to go to decarbonise the world economy,” and “When it comes to climate, timing is everything.”

The authors of the commentary have requested the world leaders to take proper action on this issue by discussing it at he G20 summit in Hamburg, Germany, on July 7-8 this year. But ever since Trump walked out of the Paris Climate Accord, he has been refusing to conversations about climate, starting with not joining a climate consensus at a G7 summit in late May.

The commentary also said that, renewable energy, mainly wind and solar must make up at least 30% of the world’s electricity supply. And no additional coal-fired power plants should be approved after 2020. Also the electric vehicles, that currently make up 1% of new car sales should account 15% of the market by then. It also asked the governments to work on the improvement of fuel efficiency by at least 20% for heavy-duty vehicles and the aviation sector to drop carbon dioxide pollution by 20% for every kilometer traveled. Greenhouse gases from deforestation and agriculture, currently about 12 percent of the global total, must be cut to zero within a decade. They also called for concrete measures to curb carbon emitted by heavy industry, as well as by buildings and infrastructure.

And lastly, they suggested that the governments and banks must to cut finances on CO2 emitting projects.