Climate challenges2020 Was Among Three Warmest Years on Record

Published 27 August 2021

A new State of the Climate report confirmed that 2020 was among the three warmest years in records dating to the mid-1800s, even with a cooling La Niña influence in the second half of the year. The major indicators of climate change continued to reflect trends consistent with a warming planet. Several markers such as sea level, ocean heat content, and permafrost once again broke records set just one year prior.

A new State of the Climate report confirmed that 2020 was among the three warmest years in records dating to the mid-1800s, even with a cooling La Niña influence in the second half of the year. New high temperature records were set across the globe. The report found that the major indicators of climate change continued to reflect trends consistent with a warming planet. Several markers such as sea level, ocean heat content, and permafrost once again broke records set just one year prior. Notably, carbon dioxide (CO2) levels in the atmosphere also reached record highs in 2020, even with an estimated 6%–7% reduction of CO2 emissions due to the economic slowdown from the global pandemic.

These key findings and others are available from the State of the Climate in 2020 report released online today by the American Meteorological Society (AMS).

The 31st annual issuance of the report, led by NOAA National Centers for Environmental Information, is based on contributions from more than 530 scientists from over 60 countries around the world and reflects tens of thousands of measurements from multiple independent datasets (highlights, full report). It provides a detailed update on global climate indicators, notable weather events and other data collected by environmental monitoring stations and instruments located on land, water, ice and in space.

The report’s climate indicators show patterns, changes and trends of the global climate system. Examples of the indicators include various types of greenhouse gases; temperatures throughout the atmosphere, ocean, and land; cloud cover; sea level; ocean salinity; sea ice extent and snow cover. 

Report highlights include these indications of a warming planet: 

·  Greenhouse gases were the highest on record. As they do each year, and again in the midst of a global pandemic that slowed economic activity around the world, the major greenhouse gas concentrations, including CO2, methane (CH4) and nitrous oxide, rose to new record high values during 2020. The global annual average atmospheric CO2 concentration was 412.5 parts per million. This was 2.5 parts per million greater than 2019 amounts and was the highest in the modern 62-year measurement record and in ice core records dating back as far as 800,000 years. The year over year increase of methane (14.8 parts per billion) was the highest such increase since systematic measurements began.