Emissions of planet-warming gases will hit an all-time high this year, according to a new report.
The figures are the latest indication of how far the world is from meeting the goal set out in Paris in 2015 to avoid the worst impacts of global warming.
The report comes as U.N. negotiators meet in Poland for the latest round of talks on confronting climate change.
Emissions are projected to rise 2.7 percent this year, according to three studies released Wednesday from the Global Carbon Project, an international scientific collaboration of academics, governments and industry that tracks greenhouse gas emissions. That follows a 1.6 percent rise last year. However, emissions were stable for the three years before that.
"Possibly, this year is unusual," said lead author Corinne Le Quere at the University of East Anglia. But probably not, she added. "We think that emissions are probably still going to go up for some years unless things change drastically."
"I'm not that surprised," said Alex Trembath of the Breakthrough Institute research center, who was not involved in the research. "The world economy is growing, and the cheapest, most scalable easiest way to meet much of that growth still comes from incumbent fossil fuel technologies."
Projected emissions from China, the world's largest source of greenhouse gases, rose by 4.7 percent this year. Le Quere said a government effort to boost construction and stimulate the economy increased demand for emissions-intensive steel, aluminum and cement.
In the United States, coal continued to give way to cleaner natural gas. But a cold winter and a hot summer both raised energy demands, contributing to an estimated 2.5 percent increase in emissions.
Rising oil use for transportation also was a factor, as American consumers are once again buying bigger cars.
Emissions declined by 0.7 percent in the 28-nation European Union, though emissions from oil increased.
The transportation sector is the "biggest problem, I would say, worldwide," Le Quere added. "We are really not making a dent in emissions from transport, in spite of the fact that the technology for electric cars is there."
The good news is that renewable energy is growing by leaps and bounds. That should help take the edge off the emissions curve, even as growth picks up in another Asian giant — India.
"We're not going to see what we saw in China in the early 2000s" when that country overtook, and then doubled, emissions of the previous leader, the United States, she said.
Trembath cautions, however, that Africa remains a question mark. "We see China- and India-like growth numbers, 5 to 10 percent annual GDP growth, coming from a lot of sub-Saharan African countries," he said. "That could mean a lot more oil consumption, a lot more natural gas consumption."
That's not a bad thing on many levels, he added. "These are desperately poor countries that are just trying to achieve the same standard of living we enjoy in the United States."