Editing IPCC:AR6/WGIII/Chapter-2 (section)

==== 2.4.2.1 Energy Systems ====

<div id="h3-5-siblings" class="h3-siblings"></div>

Global energy system emissions growth has slowed down in recent years, but global oil and gas use was still growing ( [[#Jackson--2019|Jackson et al. 2019]] ) and the sector remained the single largest contributor to global GHG emissions in 2019 with 20 GtCO 2 -eq (34%) ( ''high confidence'' ) (Figure 2.17). Most of the 14 GtCO 2 -eq from electricity and heat generation (23% of global GHG emissions in 2019) were due to energy use in industry and in buildings, making these two sectors also prominent targets for mitigation ( [[#Davis--2018|Davis et al. 2018]] ; Crippa et al. 2019) (see subsections 2.4.2.2 and 2.4.2.3 below).

<div id="_idContainer045" class="Basic-Text-Frame"></div>

[[File:a9fbb7e28d049e20bdcbeab8226f3368 IPCC_AR6_WGIII_Figure_2_17.png]]

'''Figure 2.17''' '''|''' '''Trends and drivers of global energy sector emissions (see Figure 2.16 caption for details) with energy measured as primary energy supply.'''

Growth in CO 2 emissions from energy systems has closely tracked rising GDP per capita globally ( [[#Lamb--2021b|Lamb et al. 2021b]] ), affirming the substantial literature describing the mutual relationship between economic growth and demand for energy and electricity ( ''robust evidence'' , ''high agreement'' ) ( [[#Khanna--2009|Khanna and Rao 2009]] ; [[#Stern--2011|Stern, 2011]] ). This relationship has played out strongly in developing regions, particularly in Asia, where a massive scale up of energy supply has accompanied economic growth – with average annual increases of energy demand between 3.8–4.3% in 2010–2019 (Figure 2.17). The key driver for slowing the growth of energy systems CO 2 emissions has been declining energy intensities in almost all regions. Annually, 1.9% less energy per unit of GDP was used globally between 2010 and 2019.

The carbon intensity of power generation varies widely between (and also within) regions (Chapter 6). In North America, a switch from coal to gas for power generation (Peters et al. 2017, 2020; [[#Feng--2019|Feng 2019]] ; [[#Mohlin--2019|Mohlin et al. 2019]] ) as well as an overall decline in the share of fossil fuels in electricity production (from 66% in 2010 to 59% in 2018) ( [[#Mohlin--2019|Mohlin et al. 2019]] ) has decreased carbon intensity and CO 2 emissions. Since 2007, Europe’s carbon intensity improvements have been driven by the steady expansion of renewables in the share of electricity generation ( ''medium evidence'' , ''high agreement'' ) (Peters et al. 2017, 2020; [[#Le%20Quéré--2019|Le Quéré et al. 2019]] ; [[#Rodrigues--2020|Rodrigues et al. 2020]] ). Some studies attribute these effects to climate policies, such as the carbon floor price in the UK, the EU emissions trading scheme, and generous renewable energy subsidies across the continent ( [[#Dyrstad--2019|Dyrstad et al. 2019]] ; H. [[#Wang--2020|Wang et al. 2020]] ). South-East Asian developed countries and Australia, Japan and New Zealand stand out in contrast to other developed regions, with an increase of regional carbon intensity of 1.8 and 1.9% yr –1 , respectively (Figure 2.17). Generally, the use of natural gas for electricity production is growing strongly in most countries and gas has contributed to the largest increase in global fossil CO 2 emissions in recent years ( [[#Jackson--2019|Jackson et al. 2019]] ; [[#Peters--2020|Peters et al. 2020]] ). Furthermore, gas brings the risk of increased methane (CH 4 ) emissions from fugitive sources, as well as large cumulative emissions over the lifetime of new gas power plants that may erase early carbon intensity reductions ( [[#Shearer--2020|Shearer et al. 2020]] ).

The growth of emissions from coal power slowed after 2010, and even declined between 2011 and 2019, primarily due to a slowdown of economic growth and fewer coal capacity additions in China ( [[#Friedlingstein--2019|Friedlingstein et al. 2019]] ; [[#Peters--2020|Peters et al. 2020]] ). Discussions of a global ‘peak coal’, however, may be premature, as further growth was observed in 2019 ( [[#Friedlingstein--2019|Friedlingstein et al. 2019]] ; [[#Peters--2020|Peters et al. 2020]] ). Large ongoing and planned capacity increases in India, Turkey, Indonesia, Vietnam, South Africa, and other countries has become a driver of thermal coal use after 2014 ( [[#UNEP--2017|UNEP 2017]] ; [[#Edenhofer--2018|Edenhofer et al. 2018]] ; Steckel et al. 2019).

<div id="2.4.2.2" class="h3-container"></div>

<span id="industry-sector"></span>