Pledges made by so far by countries around the globe to cut greenhouse gas emissions fall strikingly short of the profound changes necessary to avoid the most catastrophic impacts of climate change, the United Nations said Friday. The U.N. analysis comes as presidents and prime ministers face pressure to ramp up the promises they made as part of the Paris climate accord in 2015. Through the end of last year, roughly 75 countries representing about 30 percent of global emissions had updated their initial plans ahead of a key U.N. climate summit this fall in Scotland.

But so far, U.N. officials reported Friday, those more ambitious pledges are hardly ambitious enough. Even if countries follow through, their combined impacts would put the world on a path to achieve only a 1 percent reduction in global emissions by 2030, compared to 2010 levels. By contrast, scientists have said that emissions must fall by nearly 50 percent this decade for the world to realistically have a shot at avoiding devastating temperature rise.

Only two of the world’s 18 largest emitters — the European Union and the United Kingdom — submitted plans with substantially bolder emissions-cutting targets in 2020. So far, they are the exception among the globe’s biggest carbon polluters.

“One thing that gets lost in this report’s top-line findings is the deeply encouraging news that a number of countries put forward really bold climate targets last year, such as Colombia, Argentina, the United Kingdom and the European Union,” Helen Mountford, vice president for climate and economics at the World Resources Institute, said in a statement.

China, the world’s largest emitter, has a developing economy that relies heavily on coal-burning power plants. The Chinese have no plans to begin scaling back their pollution until emissions levels peak around 2030. They have said they expect to stop adding to the global warming problem by 2060.

The United States, the world’s second-biggest emitter, only just rejoined the Paris accord. President Biden has made clear that he wants to put the country on a path to decarbonize the electricity sector by 2035, and to eliminate the nation’s carbon footprint 15 years after that.

The U.N. analysis on Friday echoed the findings of another report from earlier this month, which found that the current national pledges to cut emissions are woefully weak. Even if countries were to meet their existing pledges, that study found, the world has only about a 5 percent chance to limit the Earth’s warming to “well below” 2 degrees Celsius (3.6 Fahrenheit) over preindustrial levels — a key aim of the international agreement.

Adrian Raftery, a University of Washington statistics professor and co-author of the study, and a colleague calculated that global emissions would need to fall steadily — about 1.8 percent each year on average — to put the world on a more sustainable trajectory. While no two countries are alike, that amounts to overall emissions reductions roughly 80 percent more ambitious than those pledged under the Paris agreement, he said.