Emissions of carbon dioxide – the greenhouse gas most responsible for global warming – reached an all-time high in 2018, scientists announced Wednesday.
Global carbon dioxide levels in our atmosphere “are now higher than they’ve been for millions of years,” said Rob Jackson of the Global Carbon Project at Stanford University, who was one of the study co-authors.
The emissions have now risen for a second year, after three years of little-to-no growth from 2014 to 2016. This uptick in global carbon emissions puts the goals from the landmark Paris Agreement in jeopardy.
“We thought, perhaps hoped, emissions had peaked a few years ago,” said Jackson. “After two years of renewed growth, that was wishful thinking.”
The burning of fossil fuels such as coal, oil and gas releases greenhouse gases like carbon dioxide and methane into Earth’s atmosphere and oceans. The extra CO2 has caused temperatures to rise to levels that cannot be explained by natural factors, scientists report.
According to the study, global carbon dioxide emissions from fossil fuel sources – which are about 90 percent of all emissions from human activities – will reach a record high of just over 37 billion tons in 2018, an increase of 2.7 percent over emissions output in 2017.
“Emissions need to peak and rapidly decrease to address climate change,” said Corinne Le Quéré of the University of East Anglia. “With this year’s growth in emissions, it looks like the peak is not yet in sight.
“To limit global warming to the Paris Agreement goal of 1.5 degrees Celsius, CO2 emissions would need to decline by 50 percent by 2030 and reach net zero by around 2050,” she added. “We are a long way from this and much more needs to be done because if countries stick to the commitments they have already made, we are on track to see 3 degrees Celsius of global warming.”
The record high of carbon emissions in 2018 has been driven by a solid growth in coal use for the second year in a row, along with sustained growth in oil and gas use. The planet’s five biggest emitters in 2018 are China, the United States, India, Russia, and Japan.
The study was published simultaneously Wednesday in the journals Nature, Earth System Science Data and Environmental Research Letters.