Three years ago, world leaders from nearly every country around the world laid out specific plans to fight climate change that included strategies to slash their greenhouse gas emissions. Those commitments generated optimism that the world might finally address global warming and helped seal the deal on the Paris Agreement.

Now, the majority of G20 countries aren’t following through on their promises, according to a new report from the United Nation Environment Programme. And, even if countries followed through, the world would fall short of limiting temperature rise to safe levels.

“Countries are not doing enough,” says UNEP official Phillip Drost, who coordinated the report. “We need to mitigate more emissions.”

The report is the latest stark warning that the clock is ticking for countries to address climate change. Global carbon dioxide emissions grew in 2017 after three years of stabilizing and show no signs of peaking, according to the report. Some leading scientists say emissions need to peak and decline by 2020 for the world to keep global temperatures from rising to unsafe levels.

The report looks specifically at G20 countries and shows that the vast majority, including the United States, the world’s second largest emitter, are not on track to reduce their emissions in line with their 2015 commitments. And some of the countries that are — such as Russia and Turkey — have been criticized for setting unambitious targets. China is one notable exception to the trend: the country’s greenhouse gas emissions will likely begin to decline before 2030 as it promised even as it continues its breakneck economic growth.

But progress in China, the top global emitter, is not enough to make up for the rest of the world. Looked at collectively, countries would need to increase their commitments fivefold to keep temperature rise below 1.5°C, according to the report. They would need to increase their commitments three-fold to keep them below 2°C. Scientists say crossing either thresholds could unleash a slew of irreversible consequences.

The backsliding is largely the result of increased economic growth in 2017, as GDP growth typically correlates with increased CO2 emissions. That trend was temporarily broken between 2014 and 2016 when emissions stabilized, and in the U.S. emissions actually declined last year even as the economy roared. (The decrease was not enough to keep the country in line to meet the goal of reducing them by at least 26% by 2025, however.)

But beyond economic growth the global fight against climate change has also encountered a slew of political challenges since 2015 ranging from the election of President Donald Trump, who denies the science of climate change and has promised to pull the U.S. out of the Paris Agreement, to the closing of nuclear power plants in developed countries like Germany. “Germany is going to fail its climate goal,” Rita Schwarzelühr-Sutter, a state secretary at Germany’s Ministry for Environment, Nature Conservation and Nuclear Safety, told TIME earlier this year. “Now every sector needs to contribute.”

Stemming temperature rise and all the associated effects doesn’t require the advent of a moonshot solution, and the UNEP report points to several paths to address warming using existing policy solutions. A price on carbon of $70 per ton of carbon dioxide, implemented through a measure like a carbon tax, could cut emissions by 40% ton in some countries. Cutting subsidies for the fossil fuel industry could cut global emissions by 10%. And the effort by cities, states and other sub-national governments could expand to incorporate more communities. “The gap can be bridged,” says Drost.

The report is the latest in the string of important reports on climate change released in recent months. A report from the UN’s climate science body released in October showed that the consequences of temperatures rising more than 1.5°C would be catastrophic for many parts of the world, and last week a publication from 13 U.S. federal agencies showed how climate change is already damaging American communities and could cause hundreds of billions of dollars of damage to the country’s economy.

Climate scientists and advocates hope that the reports will build momentum ahead of the upcoming UN climate change conference scheduled to begin in Poland next week. Diplomats from nearly 200 countries need to reach agreement on a slew of technical issues to implement the Paris Agreement and keep it from fading in relevance.

“We do have a possibility to have a positive outcome,” Patricia Espinosa, head of the UN’s climate change body, told TIME about the upcoming negotiations. “But I think that we are still facing a lot of challenges and one of them is the lack of time.”

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Write to Justin Worland at justin.worland@time.com.