State of the Climate: 2020 was among the three warmest years on record
Greenhouse gases were the highest on record. The global annual average atmospheric CO2 concentration was 412.5 parts per million (ppm). This was 2.5 ppm 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 in methane (14.8 parts per billion) was the highest such increase since systematic measurements began.
Global surface temperature reached a near-record high. Annual global surface temperatures were 0.97°–1.12°F or 0.54°–0.62°C above the 1981–2010 average, depending on the dataset used. This places 2020 among the three warmest years since records began in the mid- to late 1800s.
Sea surface temperatures reached a near-record high. The globally averaged 2020 sea surface temperature was the third highest on record, surpassed only by 2016 and 2019, both of which were associated with El Niño events.
Global sea level was highest on record. For the ninth consecutive year, global average sea level rose to a new record high and was about 3.6 inches (91.3 mm) higher than the 1993 average, the year that marks the beginning of the satellite altimeter record. Global sea level is rising at an average rate of 1.2 inches (3.0 cm) per decade due to changes in climate. Melting of glaciers and ice sheets, along with warming oceans, account for the trend in rising global mean sea level.
According to JRC scientist Nadine Gobron, who co-edited the global chapter and was among the scientists from around the world who contributed to the report,
This report includes new indicators that show how research using space observations, such as Copernicus data, makes a significant step forward in assessing climate change impacts on our planet.