Trends in global CO2 and total greenhouse gas emissions: 2018 report

In 2017, the growth in global greenhouse gas emissions resumed at a rate of 1.3% per year, reaching 50.9 gigatonnes in CO2 equivalent. This was mainly due to emissions of CO2 and methane, which increased by 1.2%.

Growth in global greenhouse gas emissions resumed in 2017

Mainly due to CO2 and methane, after two years of almost no growth

The increase in global greenhouse gas emissions  was mainly due to increasing emissions of CO2 and methane, which increased by 1.2% after two years of almost no growth. With a share of about 73% for CO2 and 18% for methane, these emissions form the lion’s share of global greenhouse gas emissions (excluding those from land-use change). The other greenhouse gases are nitrous oxide (N2O) (6% share) and fluorinated gases (so-called F-gases with a share of 3%), the emissions of which continued to grow at rates similar to those in 2015 and 2016. Present greenhouse gas emissions are about 55% higher than in 1990 and 40% higher than in 2000 (see Figure).

Increase in greenhouse gas emissions in 2017 in five largest emitting countries and European Union

Five countries and the European Union emit the largest amounts of greenhouse gas emissions, together accounting for 63%, globally. China accounts for 27%, the United States for 13%, the European Union for 9%, India for 7%, the Russian Federation for 5% and Japan for 3%.  In 2017, most of them showed increasing emissions, with India (+2.9%), China (+1.1%), European Union (+1.1%), Russian Federation (+1.0%) and Japan (+0.3%) (except for the United States, where emissions remained constant, at 0.1%).

Uncertainty in non-CO2 greenhouse gas emissions much larger than for CO2 emissions

The estimated uncertainty range is much larger for non-CO2 emissions than for CO2 emission estimates. However, for total global greenhouse gas emissions, the uncertainty is estimated at 10%, mainly because global CO2 emissions account for three-quarters of total greenhouse gas emissions and its uncertainty is about 10%.


PBL Authors
Jos Olivier Jeroen Peters


Publication title
Trends in Global CO2 and Total Greenhouse Gas Emissions
Publication subtitle
2018 report
Publication date
5 December 2018
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