In 2017, the warmest year on record of years without the occurrence of El Niño, and a year with normal global economic growth, the increase 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 (CH4), 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 included under the UN Climate Convention 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). The 1.3% growth rate of greenhouse gas emissions is similar to those between 2012 and 2014 and is, coincidentally, also the average annual growth rate in the decades before 2003.
These are the main conclusions from the 2018 report ‘Trends in global CO2 and total greenhouse gas emissions’ by PBL Netherlands Environmental Assessment Agency. This is the most comprehensive report on global greenhouse gas emissions up to 2017, as it presents detailed data on emissions of all greenhouse gases, not only CO2.
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% (Figure S.1).
These countries also have the highest CO2 emission levels. In 2017, most of the five largest emitting countries and the European Union showed a real increase in greenhouse gas 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%).
The ranking of countries is quite different when using per-capita emissions. Except for India (2.7 tCO2 eq/cap), all other large emitting countries and the EU have per-capita emission levels that are significantly higher than those for the rest of the world and the world average (6.7 tCO2 eq/cap). With 9.6 tCO2 eq/cap China ranks 4th, which is higher than the European Union with 9.0 tCO2 eq/cap. Although greenhouse gas emissions in the United States have been steadily decreasing since 2000, from 25.0 tCO2 eq/cap to about 20.5 tCO2 eq/cap by 2017, it is the highest amount among the top 5 emitting countries and the EU, but it is surpassed by three other G20 countries: Canada, Australia and Saudi Arabia. The Russian Federation (16.3 tCO2 eq/cap), and Japan (11.7 tCO2 eq/cap) make up the top 3, of the five largest G20 countries.
Global CO2 emissions increasing after a standstill of two years
The flat global CO2 emissions in 2015 and 2016 (0.0% and +0.4%) were mainly due to declining global coal consumption, caused by three years of decreasing coal consumption in China and declines in the United States and the European Union, mainly from increased renewable power generation, in particular, wind and solar power, and fuel switching to natural gas in power plants.
In 2017, the 1.2% increase in global CO2 emissions to 37.1 Gt CO2 was mainly due to a new 0.7% rise in global coal consumption, mainly caused by a strong 4.5% increase in India (twice the rate of 2016) and increases in Turkey (+16%), South Korea (+5.4%), Indonesia (+7.1%) and China (+0.2%). In contrast, coal consumption continued to decrease in the United States and the European Union by more than 2%.
In 2017, total energy demand increased by 2.3%, half of the increased demand was met by fossil fuels and the other half by renewables plus nuclear power.
Global methane emissions increasing after two years of very slow growth
The largest sources of methane emissions are fossil fuel production (35%), ruminant livestock, such as cattle (23%), rice production (10%) and landfill and waste water (16%). In 2017, global CH4 emissions increased by 1.2% to a total of 370 megatonnes CH4 (9.3 Gt CO2 eq), which is 21% higher than in 1990. The increase in 2017 is markedly higher than in 2015 and 2016, which saw respective growth rates of only 0.5% and 0.4%, but again similar to growth rates in the three years before that.
The sources that contributed most to the increase in 2017 were coal production (+4.2%), livestock and particularly non-dairy cattle (+1.0%), waste water (1.8%) and natural gas transmission (+3.3%).
With a 2.1% increase in its CH4 emissions, China accounted for one third of the total net increase, followed by Iran (+7.1%), India (+1.2%), the United States (+1.0%) and the Russian Federation (+1.1%).
This is the second time that total global greenhouse emissions, including non-CO2 emissions, are reported, using data from the EC-JRC/PBL Emissions Database for Global Atmospheric Research (EDGAR) for 1970–2012, and preliminary estimates for 2013–2017, mostly based on very recent statistics and, where required, extrapolation of past trends. The data were also used in the UNEP Emissions Gap Report 2018, which was released last week.
- For more information on the CO2 emissions up to 2017 at country level, see the EC-JRC report ‘Fossil CO2 emissions of all world countries; 2018 report’ (forthcoming).
- For more information on the analysis of the long-term trend in total primary energy supply using a so-called Kaya decomposition, see the PBL report of 2017.