Emissions Trends and Drivers

Abstract

Global net anthropogenic greenhouse gas (GHG) emissions during the last decade (2010-2019) were higher than at any previous time in human history (high confidence).Since 2010, GHG emissions have continued to grow, reaching 59 ± 6.6 GtCO 2 -eq in 2019, 1 but the average annual growth in the last decade (1.3%, 2010-2019) was lower than in the previous decade (2.1%, 2000-2009) (high confidence).Average annual GHG emissions were 56 ± 6.0 GtCO 2 -eq yr -1 for the decade 2010-2019 growing by about 9.1 GtCO 2 -eq yr -1 from the previous decade (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009) -the highest decadal average on record (high confidence).{2.2.2, Table 2.1, Figure 2.2, Figure 2.5}Emissions growth has varied, but persisted across all groups of GHGs (high confidence).The average annual emission levels of the last decade (2010-2019) were higher than in any previous decade for each group of GHGs (high confidence).In 2019, CO 2 emissions were 45 ± 5.5 GtCO 2 , 2 CH 4 11 ± 3.2 GtCO 2 -eq, N 2 O 2.7 ± 1.6 GtCO 2 -eq and fluorinated gases (F-gases: HFCs, PFCs, SF 6 , NF 3 ) 1.4 ± 0.41 GtCO 2 -eq.Compared to 1990, the magnitude and speed of these increases differed across gases: CO 2 from fossil fuel and industry (FFI) grew by 15 GtCO 2 -eq yr -1 (67%), CH 4 by 2.4 GtCO 2 -eq yr -1 (29%), F-gases by 0.97 GtCO 2 -eq yr -1 (254%), and N 2 O by 0.65 GtCO 2 -eq yr -1 (33%).CO 2 emissions from net land use, land-use change and forestry (LULUCF) have shown little long-term change, with large uncertainties preventing the detection of statistically significant trends.F-gases excluded from GHG emissions inventories such as chlorofluorocarbons and hydrochlorofluorocarbons are about the same size as those included (high confidence).{2.2.1, 2.2.2, Table 2.1, Chapter 2 Emissions Trends and Drivers 2 Developed Countries tend to be net CO 2 emission importers, whereas developing countries tend to be net emission exporters (robust evidence, high agreement).Net CO 2 emission transfers from developing to Developed Countries via global supply chains have decreased between 2006 and 2016.Between 2004 and 2011, CO 2 emission embodied in trade between developing countries have more than doubled (from 0.47 to 1.1 Gt) with the centre of trade activities shifting from Europe to Asia.{2.3.4,Figure 2.15} Emissions from developing countries have continued to grow, starting from a low base of per capita emissions and with a lower contribution to cumulative emissions than Developed Countries (robust evidence, high agreement).Average 2019 per capita CO 2 -FFI emissions in three developing regions -Africa (1.2 tCO 2 per capita), Asia and Pacific (4.4 tCO 2 per capita), and Latin America and Caribbean (2.7 tCO 2 per capita) -remained less than half that of Developed Countries (9.5 tCO 2 per capita) in 2019.CO 2 -FFI emissions in the three developing regions together grew by 26% between 2010 and 2019, compared to 260% between 1990 and 2010, while in Developed Countries emissions contracted by 9.9% between 2010 and 2019, and by 9.6% between 1990 and 2010.Historically, the three developing regions together contributed 28% to cumulative CO 2 -FFI emissions between 1850 and 2019, whereas Developed Countries contributed 57% and Least-Developed Countries contributed 0.4%.{2.2.3, Figures 2.9 and 2.10} Globally, GHG emissions continued to rise across all sectors and subsectors; most rapidly in transport and industry (high confidence).In 2019, 34% (20 GtCO 2 -eq) of global GHG emissions came from the energy sector, 24% (14 GtCO 2 -eq) from industry, 22% (13 GtCO 2 -eq) from agriculture, forestry and other land use (AFOLU), 15% (8.7 GtCO 2 -eq) from transport and 5.6% (3.3 GtCO 2 -eq) from buildings.Once indirect emissions from energy use are considered, the relative shares of industry and buildings emissions rise to 34% and 16%, respectively.Average annual GHG emissions growth during 2010 to 2019 slowed compared to the previous decade in energy supply (from 2.3% to 1.0%) and industry (from 3.4% to 1.4%, direct emissions only), but remained roughly constant at about 2% per year in the transport sector (high confidence).Emission growth in AFOLU is more uncertain due to the high share of CO 2 -LULUCF emissions (medium confidence).{2.4.2, Figure 2.13, Figures 2.16 to 2.21} Average annual growth in GHG emissions from energy supply decreased from 2.3% for 2000-2009 to 1.0% for 2010-2019 (high confidence).This slowing of growth is attributable to further improvements in energy efficiency (annually, 1.9% less energy per unit of GDP was used globally between 2010 and 2019).Reductions in global carbon intensity by -0.2% yr -1 contributed further -reversing the trend during 2000 to 2009 (+0.2% yr -1 ) (medium confidence).These carbon intensity improvements were driven by fuel switching from coal to gas, reduced expansion of coal capacity, particularly in Eastern Asia, and the increased use of renewables.{2.2.4,2.4.2.1, Figure 2.17} 3 Decent Living Standard