Even before the international Paris Agreement was completed last December, we had some encouraging news about greenhouse gas emissions. Despite an increase in global GDP, emissions were basically unchanged from 2014 to 2015. Previously, only recessions interrupted the relentless year-over-year rise of emissions. Now, an early projection for 2016 looks just about as good.

Keeping the books on global emissions and the rising concentration of atmospheric CO 2 is an incredibly complex undertaking—it’s not as easy as checking your electric utility statement. The overall carbon budget for our atmosphere involves all the carbon exchanged with land ecosystems and the oceans, and there are lots of human emissions beyond energy. In the end, you can figure out how much human activities released and how much ended up in the atmosphere.

In a new paper, a huge team of researchers led by the University of East Anglia’s Corinne Le Quéré has published the latest update to the state of Earth’s carbon budget. This effort involves many sources of information, including tracking fossil fuel use for power, industry, and in homes, as well as items like the production of cement (which releases CO 2 directly) and global trade. On top of that, there are data and models used to monitor the world’s ecosystems.

Updating with the best information for 2015, they revise emissions very slightly upward from down 0.06 percent (compared to the year before) to up 0.6 percent. The difference is much smaller than the error bars on these estimates, so the upshot is still that there was essentially no change. That’s significant, given that annual emissions rose rapidly through the early 2000s.

Their estimate for 2016 evaluates Chinese emissions through September compared to the same chunk of 2015, takes advantage of the International Energy Agency’s statistics for the US, and estimates the rest of the world based on the relationship between GDP and emissions. Accounting for the fact that 2016 was a leap year with an extra day, they estimate that China’s emissions will drop by about 0.5 percent (largely due to coal use declining nearly two percent), and that US emissions will drop by a little more than 1.5 percent. Emissions from the rest of the world look to increase by about 1 percent, leaving a grand increase of only about 0.2 percent. So once again, global emissions basically look stable, which is good news.

That doesn’t mean atmospheric CO 2 isn’t increasing, though. Global emissions will have to drop to around zero before CO 2 stops accumulating in the atmosphere, and we’re still hanging around 9.9 billion tons of carbon emitted every year. There is also some natural variability from year to year due to things like El Niño, which affects the rest of the carbon budget. As in other El Niño years, CO 2 jumped up a little extra in 2016—increasing by about 3 parts per million to a little over 400 parts per million—because terrestrial ecosystems soaked up a little less carbon than average.

Totaling up all estimated emissions since 1870, then, we’re at about 565 billion tons of carbon. The 2013 IPCC report put the total amount of carbon we can emit before warming the globe by 2°C at 800 billion tons, so emissions will have to drop off rapidly if we’re going to slip under that bar.

Open Access at Earth System Science Data, 2016. DOI: 10.5194/essd-8-1-2016 (About DOIs).