Global energy-related CO2 emissions remained little changed in 2019 at 33.2 gigatonnes (Gt), following two years of increases. This stabilisation resulted mainly from a sharp decline in CO2 emissions from the power sector in advanced economies. Power sector emissions fell thanks to the expanding role of renewable sources (mainly wind and solar PV), fuel switching from coal to natural gas, and higher nuclear power output.

Energy-related CO2 emissions, 1990-2019


Global CO2 emissions from coal use declined by more than 220 million tonnes (Mt), or 1.5%, offsetting increases in emissions from oil and natural gas. In advanced economies, emissions fell by almost 380 Mt, or 3.2%, with the power sector responsible for nearly 90% of the drop.

Milder weather in many large economies played a key part, reducing emissions by over 200 Mt and reversing some of the increases caused by higher demand for space heating and cooling in 2018. Weaker global economic growth in 2019 also played an important role, moderating the increase in emissions in major emerging economies, especially in India.

The spread of renewables played the biggest role in containing global energy-related CO2 emissions in 2019. Increasing deployment of renewables in almost all regions reduced potential growth in emissions by over 330 Mt. China alone accounted for over one-third of the savings from renewables, while the European Union contributed to around 70 Mt of savings and the United States 35 Mt.

Improvements in energy efficiency also had a major impact on curtailing emissions growth in 2019. Without the improvements in the average energy efficiency of the world’s cars, appliances, industrial processes, power plants and other energy-using equipment, global CO2 emissions would have been nearly 200 Mt higher in 2019, almost equivalent to the energy-related CO2 emissions of Spain today. While this is welcome, it is important to note that the rate of energy efficiency improvement sloed again in 2019. Few new energy efficiency policies were implemented and lower economic growth slowed the replacement of old stock with higher-efficiency new equipment.

Change in global energy-related CO2 emissions and avoided emissions, 2018 compared to 2019


Fuel switching from coal to gas accelerated in 2019, reducing carbon emissions by 120 Mt, more than 30 Mt higher than the savings from coal to gas switching in 2018. Emissions reductions from coal to gas fuel switching were concentrated in the European Union and the United States. In these economies, gas became an increasingly attractive alternative to coal for electricity generation because of the evolution of gas and CO2 prices. Gas consumption also grew substantially in China, where air quality policies continue to encourage the uptake of gas for heating and industrial uses.

Nuclear power also played a significant role in countering further increases in emissions from fossil fuels in 2019. Increases in nuclear output reduced potential emissions growth by close to 100 Mt of CO2. The majority of the increase in nuclear output was in China, where many reactors commissioned in late 2018 completed their first full year of operation in 2019.

In Japan, reactors restarted in recent years increased their output in 2019. Nuclear output also increased in Korea. Electricity generation from the world’s nuclear fleet reached a record level of 2 800 TWh, meeting 10% of global electricity demand with output higher than pre-Fukushima levels.

As economies expanded in 2019, increasing demand for energy services put upward pressure on emissions. But the combined impact of growing deployment of renewables, energy efficiency improvements, coal to gas fuel switching, and greater output from nuclear generators was sufficient to offset this pressure. The importance and scale of many of these effects suggests clean energy transitions are under way, led by the power sector.

Global power sector emissions declined by more than 170 Mt, or 1.3%, in 2019. The biggest falls took place in advanced economies, where CO2 emissions have sunk to the levels of the late 1980s, when electricity demand was one-third lower.

The trajectories of CO2 emissions differed from region to region in 2019. In advanced economies, emissions declined by 380 Mt, led by declines in the power sector. In the rest of the world there was an overall increase, of 360 Mt. In many major economies, however, such as India, Indonesia, and to a lesser extent China, emissions growth did slow.

Change in energy-related CO2 emissions in selected regions, 2018 compared to 2019


Although economic growth in advanced economies averaged 1.7% in 2019, total energy‑related CO2 emissions fell by 3.2%. The power sector led the decline. It now accounts for 34% of energy-related emissions across advanced economies, down from a high of 38% in 2012. The average CO2 emissions intensity of electricity generation declined by nearly 6.4% in 2019, almost three times faster than the average rate over the past decade. In absolute terms, the average emissions intensity of electricity generation in 2019 was 340 grams of CO2 per kilowatt hour, lower than all but the most efficient gas-fired power plants.

Generation from coal-fired plants in advanced economies declined by nearly 15%. The drop was due to continued growth of renewables, coal-to-gas fuel switching, a rise in nuclear power and lower electricity demand.

The growth of renewables in electricity generation in advanced economies delivered 140 Mt of CO2 emissions savings. Wind accounted for the biggest share of the increase, with output expanding 12% from 2018 levels. Among renewable sources, solar PV grew the fastest, helping to push renewables’ share of total electricity generation close to 28%. 

Coal-to-gas fuel switching for power generation, which avoided 100 Mt of CO2 in advanced economies, was particularly strong in the United States due to record low natural gas prices. Higher nuclear power generation in advanced economies, particularly in Japan and Korea, avoided over 50 Mt of CO2.

The United States was the country that experienced the largest decline in energy-related CO2 emissions in 2019 – a fall of 131 Mt, or 2.7%, to 4.8 Gt. US emissions are now down almost 1 Gt from their peak in 2000, the largest absolute decline by any country over that period. A 15% reduction in the use of coal for power generation underpinned the decline in overall US emissions in 2019.

US coal-fired power plants faced even stronger competition from natural gas-fired generation, with benchmark gas prices an average of 20% lower than 2018 levels. As a result, gas increased its share in electricity generation to a record high of 38%. Overall electricity demand declined because demand for air-conditioning and heating was lower as a result of milder summer and winter weather.

Energy-related CO2 emissions in the European Union (including the United Kingdom) dropped by 175 Mt, or 5.7%, to reach 2.9 Gt. The power sector drove the trend, with a decline of 120 Mt of CO2, or 12%, resulting from increasing renewables and switching from coal to gas. Output from coal-fired power plants dropped by more than 25% in 2019, while gas-fired generation increased by close to 13% to overtake coal for the first time.

Germany spearheaded the decline in emissions in the European Union. Its emissions fell by 8% to 620 Mt of CO2, a level not seen since the 1950s, when the German economy was around 10 times smaller. Output from the country’s coal-fired power fleet fell by more than 25% as electricity demand declined and generation from renewables increased, especially wind, which rose 12%. With a share of over 40% in 2019, renewables for the first time generated more electricity than Germany’s coal-fired power stations.

The United Kingdom continued its strong decarbonisation progress as output from coal-fired power plants fell to only 2% of electricity generation. Rapid expansion of output from offshore wind, as additional projects came on line in the North Sea, was a driving factor behind this decline. Renewables provided about 40% of electricity supply in the United Kingdom, with gas supplying a similar amount. The share of renewables rose even higher in the latter part of the year, with wind, solar PV and other sources generating more electricity than all fossil fuels combined during the third quarter.

Electricity generation and power sector CO2 emissions in advanced economies, 1971-2019


In Japan, energy-related CO2 emissions fell 4.9% to 1 025 Mt in 2019, the fastest pace of decline since 2009. The power sector experienced the largest drop in emissions as reactors that had recently returned to operation contributed to a 32% increase in nuclear power output. This allowed Japan to reduce electricity generation from plants fired by coal, gas and oil.

In the rest of the world, CO2 emissions rose by 361 Mt in 2019, or 1.7%. These economies now account for two-thirds of global CO2 emissions, an increase of over 7 percentage points since 2010. The rate of emissions growth in 2019 was markedly slower than the increase of 2.6% in 2018, however, and the average annual rise of 2.2% since 2010. The main reason for the slowdown was a stalling of emissions growth in India (adding 95 MtCO2 less to global emissions than in 2018) and a slowdown in China, where low carbon sources underwent their largest ever increase. In other developing economies in Asia, the Middle East and North Africa, emissions growth was also slower in 2019 than in 2018. 

The biggest change of pace took place in the power sector. In China, emissions from the sector grew aroundhalf the rate of 2018, and well below the average during the last decade. In India, emissions from the power sector declined in 2019, in stark contrast to the average 4.2% growth rate since 2010. While lower economic growth was the main factor behind this slowdown, renewables also had a major impact, reducing the potential increase in emissions by over 200 Mt.

Asia accounted more than 90% of the increase in emissions outside of advanced economies. Asian coal demand continued to expand, accounting for over 50% of energy use in 2019, and producing around 10 Gt of emissions. Nonetheless, low-carbon sources of energy met 30% of energy demand growth in 2019, up from 25% in 2018.

In China, emissions rose 2.3% but were tempered by slower economic growth and higher output from low-carbon sources of electricity. Low-carbon sources met 36% of energy demand growth, up from 30% in 2018. Renewables continued to expand in China, and 2019 was also the first full year of operation for seven large-scale nuclear reactors in the country.

Emissions in India rose by 0.6% in 2019, a moderate increase that marked a major decline from average annual growth of around 4% since 2010. This decline was the result of a slowdown in economic growth from 6.8% in 2018 to 4.8% in 2019. Heavy industry and manufacturing activity declined, especially in the latter half of the year, reducing demand for electricity and other fuels. A late monsoon also curbed emissions, as it reduced electricity and diesel demand for irrigation and increased generation from hydroelectricity. As a result, coal use in the power sector fell and emissions from coal-fired power were down 2% on 2018 levels. Continued growth in fossil fuel demand in other sectors of the Indian economy, notably industry, offset the decline in the power sector.

Emissions increased by 85 Mt in Southeast Asia, where the growth rate of 5.8% was only slightly below 2018 growth. Coal demand drove the increase, with emissions from coal use across Southeast Asia up 80 Mt, not too distant from the 110 Mt increase in China.

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