Editing IPCC:AR6/WGI/Chapter-6 (section)

=== Implications of COVID-19 Restrictions for Emissions, Air Quality and Climate ===

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'''Emissions reductions associated with COVID-19 containment led to a discernible temporary improvement of air quality in most regions, but changes to global and regional climate are undetectable above internal variability.''' Global anthropogenic NO <sub>x</sub> emissions decreased by a maximum of about 35% in April 2020 ( ''medium confidence'' ). There is ''high confidence'' that, with the exception of surface ozone, these emissions reductions have contributed to improved air quality in most regions of the world. Global fossil CO <sub>2</sub> emissions decreased by 7% (with a range of 5.8 – 13.0%) in 2020 relative to 2019, largely due to reduced emissions from the transportation sector ( ''medium confidence'' ). Overall, the net ERF, relative to ongoing trends, from COVID-19 restrictions was likely small and positive for 2020 (less than 0.2 W m <sup>–2</sup> ), thus temporarily adding to the total anthropogenic climate influence, with positive forcing from aerosol changes dominating over negative forcings from CO <sub>2</sub> , NO <sub>x</sub> and contrail cirrus changes. Consistent with this small net radiative forcing, and against a large component of internal variability, Earth system model simulations show no detectable effect on global or regional surface temperature or precipitation ( ''high confidence'' ). {Cross-Chapter Box 6.1}

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