Greenhouse gas concentrations, global sea levels hit record highs in 2020: NOAA

The concentration of greenhouse gases in Earth’s atmosphere hit their highest level ever recorded in 2020, while the year was overall the warmest on record, according to the National Oceanic and Atmospheric Administration’s (NOAA) annual review.

NOAA’s 31st State of the Climate report released Wednesday found that even as the coronavirus pandemic drastically reduced economic activity, greenhouse gas concentrations hit 412.55 parts per million (PPM). This represented both a 2.5 PPM increase from 2019 and the highest level recorded in six decades.

Average methane concentration also reached a record high in 2020, according to the report, as well as an all-time high year-over-year increase of 14.8 parts per billion.

The same report found a record high for global sea levels for the ninth year in a row. Sea levels in 2020 were about 3.6 inches above the 1993 average, according to the NOAA, and levels are increasing at an average of 1.2 inches per decade due to melting ice sheets and glaciers.

Meanwhile, annual global surface temperatures continued to warm, averaging between 0.97 and 1.12 degrees more than the average between 1981 and 2010. Overall, 2020 was the warmest year on record that did not feature an El Niño, the climate pattern that brings unusually warm temperatures to the eastern Pacific Ocean. Sea surface temperatures too neared a record high, with the third-highest average on record, behind 2016 and 2019. Both of those years featured an El Niño.

Meanwhile, oceans absorbed a record level of carbon dioxide last year — about 3 billion more metric tons than the level they release This marks the highest amount absorbed on record dating back to 1982, as well as about a 30 percent increase from the previous two decades.

The report also found a pattern of extreme weather activity last year, including 102 named tropical storms in both hemispheres. Comparatively, the 1981-2010 period saw an annual average of only 85.