On September 16, 2021, United Nations agencies*, led by the World Meteorological Organization (WMO), compiled the latest climate science-related information and jointly released United in Science 2021, calling for all nations to commit to climate action. The report summarizes the highlights of each organization's recently released institutional reports (excerpts below).

• WMO：Greenhouse gases (carbon dioxide, methane, nitrous oxide) continue to increase in 2020 to early 2021. Also, 2021 recorded devastating extreme weather and climate events such as heat waves in North America and floods in western Europe, which are considered signs of anthropogenic climate change.
• IPCC：Human influence on widespread and abrupt changes in the atmosphere, oceans, cryosphere and biosphere is beyond doubt, and the scale of events currently being experienced by the climate system is unprecedented for the past several hundred to several thousand years.
• WHO/WMO：Rising temperatures are causing heat-related health problems, with an estimated 103 billion potential work hours lost in 2019 compared to 2000; COVID-19 infections, heat waves, wildfires and air pollution are undermining human health and endangering vulnerable segments of society in particular.

* In addition to the World Meteorological Organization (WMO), the United Nations Environment Programme (UNEP), the World Health Organization (WHO), the Intergovernmental Panel on Climate Change (IPCC), the Global Carbon Project (GCP), the UNESCO Intergovernmental Oceanographic Commission (UNESCO-IOC), the World Climate Research Programme (WCRP), UK Met Office and the Japan Meteorological Agency (JMA) participated.

The next day, September 17, the United Nations released a synthesis report summarizing the Nationally Determined Contributions (NDCs) to be submitted to the United Nations by each of the 191 member countries participating in the Paris Agreement. The report warns that based on the current national reduction targets, greenhouse gas emissions in 2030 compared to 2010 levels may not be reduced, but may increase by about 16%, and that in light of the recent IPCC report, the temperature rise by the end of the century could reach 2.7°C (Code Red) without urgent climate change measures. In the light of the IPCC report, the 113 countries that updated their NDCs in the report, including the EU and the US, account for 49% of global emissions, but are expected to reduce their emissions by 12% by 2030 compared to 2010 levels. The report welcomed these developments, but said they were insufficient and called for a 45% reduction in emissions by 2030 to achieve carbon neutrality by the middle of the 21st century.

Reference

United In Science 2021: A multi-organization high-level compilation of the latest climate science information https://library.wmo.int/index.php?lvl=notice_display&id=21946#.YUL0NBlx…;

Contributor: IIYAMA Miyuki (Director, Information Program)