Global emissions of carbon dioxide are rising after three years of little-to-no growth, according to a new study released Monday, casting doubt from climate scientists that the world can head off the most damaging effects of climate change.

Most climate scientists expected greenhouse gas emissions to soon reach their peak after three stable years, encouraged by reduced coal use, especially in China, gains in energy efficiency, and a boom in renewables such as wind and solar.

However, researchers at the University of East Anglia and the Global Carbon Project have determined that global emissions will grow 2 percent in 2017 compared to 2016, reaching 41 billion tons.

The researchers say China, the world’s largest emitter, is the biggest contributor to the increase in emissions this year, with a projected growth of 3.5 percent, primarily driven by more coal use.

The projections present a challenge for policymakers participating this week in the United Nations climate change talks in Bonn, Germany.

Almost 200 countries are gathered to build off the 2015 Paris Agreement, where nearly every nation vowed to help limit the rise in global temperatures to “well below” 2 degrees Celsius, or 3.6 degrees Fahrenheit, the temperature at which many scientists say the world would see irreversible effects of climate change.

“Every year where emissions are not decreasing, and increasing, we have to cut more emissions later on to deal with higher levels of climate change,” said Corinne Le Quere, the lead author of the study and director of the Tyndall Centre for Climate Change Research at the University of East Anglia.

“The risks increase with every bit of emissions we put in the atmosphere,” Le Quere told the Washington Examiner in an interview. “Time is running out on our ability to keep warming well below 2 degrees Celsius, let alone 1.5 degrees Celsius.”

A major climate change report released this month by Trump administration scientists found it is “extremely likely” that human activities are the “dominant cause” of global warming and that the past 115 years are “the warmest in the history of modern civilization."

There is good news in the new Global Carbon Project study, Le Quere said.

Emissions are declining in major countries this year, including in the U.S. and European Union. U.S. carbon dioxide emissions are expected to drop by 0.4 percent in 2017, with coal use projected to rise slightly. Emissions will decline 0.2 percent in the EU this year. But those are smaller declines than in recent years.

Overall, 22 countries representing 20 percent of global emissions saw a decrease in emissions this year, while their economies improved. Renewable energy has increased 14 percent per year over the last five years.

Le Quere said a key question will be whether China’s increased emissions in 2017 represent a one-year blip or a new trend. China had reduced emissions for two straight years. Yet China’s emissions are rising because of stronger growth in industrial coal production and less generation of hydrocarbon, a renewable energy source, due to less rainfall.

“China is the biggest emitter, so whatever happens in China has an immediate imprint on the globe,” Le Quere said. “The big question is whether this is a new trend in China or just this year. It looks a bit more like it may be a one-year blip, with activity slowing towards the end of the year, but it’s too early to know for sure.”

China has promised to take on a leadership role in combating climate change, with the U.S. backtracking from the issue under the Trump administration. President Trump has announced his intent to withdraw from the Paris climate change agreement, which it can’t technically do until 2020. China has vowed to remain in the deal.

The U.S. would be the only country in the world not committed to the Paris agreement.

Under the Paris pact, China promised that its emissions would peak around 2030, as part of voluntary pledges submitted by every country to reduce greenhouse gas emissions.

But China's energy data is notoriously unreliable, so it’s difficult to know how much progress it’s actually making.

“China's Paris pledge is utterly meaningless,” said Paul Bledsoe, a former Clinton White House climate adviser. “Their economy will see peak emissions much sooner than 2030.”

Trump, in deciding to leave the Paris agreement, said the deal favored emerging economies such as China and India because it allowed those countries to make less stringent emissions reduction targets. India’s emissions are projected to increase 2 percent this year, but that amount is less than the 6 percent per year growth in emissions the country saw over the last decade.

India, the third-largest emitter of greenhouse gases behind China and the U.S., has slowed the expansion of its coal-fired plants, and the country has said that in a decade, it may not need to build any more coal plants. By 2030, India has vowed to reduce its emissions by 35 percent of 2005 levels.

Bledsoe argues the U.S., by leaving the Paris Agreement, is losing leverage in encouraging countries, especially China, to uphold pledges to reduce emissions.

“Let's force them to do better,” Bledsoe said of China. “Pulling out of the Paris Agreement is the exact opposite way to compel them to take a more serious pledge. It really points to the strategic flaw in the Trump administration’s disengagement on climate change. It takes a strong U.S. to force China to bend its emissions curve. We don't have any credibility on the issue.”