Editing IPCC:AR6/WGIII/Chapter-4 (section)

==== 4.2.2.4 Estimated Impact of COVID-19 and Governmental Responses on Emissions Projections ====

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The impacts of COVID-19 and national governments’ economic recovery measures on current ( [[IPCC:Wg3:Chapter:Chapter-2#2.2.2|Section 2.2.2]] ) and projected emissions of individual countries and globally under current policies scenarios until 2030 may be significant, although estimates are highly uncertain and vary across the few available studies. The analyses published to date (October 2021) are based on limited information about how COVID-19 has affected the economy and hence GHG emissions across countries so far in 2020, and also based on assumptions about COVID-19’s longer term impact. Moreover, the comparison of pre- and post-COVID-19 projections captures the impact of COVID-19 as well as other factors such as the consideration of recently adopted policies not related to COVID-19, and methodological changes.

Across different studies ( [[#Kikstra--2021|Kikstra et al. 2021]] ; [[#IEA--2020|IEA 2020]] ; [[#Dafnomilis--2021|Dafnomilis et al. 2021]] ; [[#Pollitt--2021|Pollitt et al. 2021]] ; [[#UNEP--2020a|UNEP 2020a]] ; [[#Climate%20Action%20Tracker--2020|Climate Action Tracker 2020]] ; [[#Keramidas--2021|Keramidas et al. 2021]] ; [[#Dafnomilis--2020|Dafnomilis et al. 2020]] ), the impact of the general slowdown of the economy due to the COVID-19 pandemic and its associated policy responses would lead to a reduced estimate of global GHG emissions in 2030 of about 1 to 5 GtCO 2 -eq, equivalent to 1.5–8.5%, compared to the pre-COVID-19 estimates (Table 4.SM.2). [[#Nascimento--2021|Nascimento et al. (2021)]] analyse the impacts of COVID-19 on current policy emission projections for 26 countries and regions and find a large range of emission reduction – between –1% and –21% – across these.

As indicated by a growing number of studies at the national and global level, how large near- to mid-term emissions implications of the COVID-19 pandemic are to a large degree depends on how stimulus or recovery packages are designed ( [[#Forster--2020|Forster et al. 2020]] ; [[#Gillingham--2020|Gillingham et al. 2020]] ; [[#IEA--2020|IEA 2020]] ; [[#Le%20Quéré--2020|Le Quéré et al. 2020]] ; [[#Malliet--2020|Malliet et al. 2020]] ; [[#Wang--2020|Wang et al. 2020]] ; [[#Obergassel--2021|Obergassel et al. 2021]] ; [[#Pollitt--2021|Pollitt et al. 2021]] ; [[#UNEP--2020a|UNEP 2020a]] ).

Four studies ( [[#Climate%20Action%20Tracker--2021|Climate Action Tracker 2021]] ; [[#den%20Elzen--2021|den Elzen et al. 2021]] ; [[#JRC--2021|JRC 2021]] ; [[#Riahi--2021|Riahi et al. 2021]] ) provide an update of the current policies assessment presented in Section 4.2.2.3 by taking into account the effects of COVID-19 as well as potential updates of policies. The resulting GHG emissions in 2030 are estimated to be 57 GtCO 2 -eq with a full range of 52 to 60 GtCO 2 -eq ( [[#_idTextAnchor043|Table 4.2]] ). This is a reduction of about 3 GtCO 2 -eq or 5% compared to the pre-COVID estimates from Section [[#_idTextAnchor016|4.2.2.3]] .

'''Table 4.2 | Projected global GHG emissions of current po''' '''licies by 2030.'''

{| class="wikitable"
|-
! Study

! Cut-off date

! Kyoto GHGs a [GtCO 2 -eq] median (min–max) b

! References

|-
| Climate Action Tracker

| 8/2020

| 54 (52–56)

| [[#Climate%20Action%20Tracker--2021|Climate Action Tracker (2021)]]

|-
| PBL

| 11/2020

| 58

| [[#den%20Elzen--2021|den Elzen et al. (2021)]] ; [[#Nascimento--2021|Nascimento et al. (2021)]]

|-
| JRC – GECO

| 12/2019

| 57

| [[#JRC--2021|JRC (2021)]]

|-
| ENGAGE c

| 7/2019

| 57 (52–60)

| [[#Riahi--2021|Riahi et al. (2021)]]

|-
| Total d

|
| 57 (52–60)

|
|}

Notes: a GHG emissions expressed in CO 2 -eq emission using AR6 100-year GWPs. GHG emissions from studies that provide aggregate GHG emissions using other GWPs are rescaled using 2019 GHG emissions from [[IPCC:Wg3:Chapter:Chapter-2|Chapter 2]] ( [[#Minx--2021|Minx et al. 2021]] ; [[#Crippa--2021|Crippa et al. 2021]] ). b If a range is available from a study, a median is provided in addition to the range. c Range includes estimates from four models: GEM-E3, MESSAGEix-GLOBIOM, POLES, REMIND-MAgPIE, based on sensitivity analysis. d To avoid a bias due to multiple estimates provided by the same model, only one estimate per model, typically the most recent update, is included in the median estimate for the total.

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