At the Climate Change Summit hosted by the Biden administration in late April 2021, a number of countries updated their greenhouse gas reduction targets. According to the Climate Action Tracker, which is run by a group of researchers who estimate the effect of limiting temperature rise based on national GHG emission reduction targets, recent commitments by the U.S., EU, China, Japan and other countries could limit temperature rise to 2.4°C by the end of the 21st century. Under an optimistic scenario in which countries fully implement their net zero GHG emission targets, including those that have expressed ambitious targets but have not yet reported them to the UNFCCC, global warming could be limited to 2.0°C by 2100.

One hundred thirty-one countries, accounting for 73% of global GHG emissions, have adopted or are considering net zero targets. However, even if it is possible to limit emissions to 2.4°C, this would still be 0.9°C above the 1.5°C goal of the Paris Agreement. Moreover, not all of the targets are already supported by ambitious policies. In the scenario where current policies continue, the temperature increase is projected to be 2.9°C.

According to the Climate Action Tracker, the 50-52% below 2005 levels announced by the U.S. is a significant step forward, but the Paris Agreement's 1.5°C target will require a 57-63% reduction from 2005 levels. However, to meet the 1.5°C target of the Paris Agreement, Japan needs to reduce its emissions by 57-63% compared to 2005. Japan has set a 46% reduction target based on the year 2013, but a 60% reduction is needed to meet the Paris Agreement.

Reference
Climate Action Tracker. Global update: Projected warming from Paris pledges drops to 2.4 degrees after US Summit: analysis.  PUBLISHED 2021/05/04 https://climateactiontracker.org/press/global-update-projected-warming-…;

Contributor: IIYAMA Miyuki (Director, Information Program)