Global surface air temperature anomalies during April 2020 when compared with the 1981-2010 average. (Copernicus Climate Change Service)

Last month tied for the warmest April on record for the globe, as 2020 hurtles toward the warmest year milestone.

New data, released Tuesday from the European Union’s Copernicus Climate Change Service, lends further support to the prediction that 2020 will rank among the top two warmest years recorded.

In April, the National Oceanic and Atmospheric Administration, using its own temperature monitoring data, reported that there is a 75 percent chance that 2020 will become the planet’s warmest year since instrument records began in 1880, and very likely long before that.

Human-caused climate change from increasing amounts of planet-warming greenhouse gases is vaulting temperatures higher, making it easier for a given month or year to set a new warmth milestone. Carbon dioxide is the most important long-lived greenhouse gas in the atmosphere, released by the burning of fossil fuels such as coal and oil for energy and transportation.

Daily carbon dioxide levels measured at the summit of Mauna Loa in Hawaii have reached 418 parts per million this month, the highest level in at least 3 million years. It’s expected that the monthly average value for 2020 will be set this month, and will be near 417 ppm, compared with last year’s measurement of 414.7 ppm.

The new Copernicus data shows a huge area of crimson red for the month of April, denoting much-above-average temperatures, across northern Asia, especially Siberia.

Temperatures were also well above average for the month across northern and coastal central Greenland, parts of Antarctica, areas of Alaska and the Arctic Ocean.

Global temperature departures from average are not just shades on a map, they also can have profound consequences for people and ecosystems on the ground, and under the ocean surface.

The Great Barrier Reef, a World Heritage Site, suffered its biggest coral bleaching event on record in 2020 as a marine heat wave gripped the 1,400-mile-long biodiversity hot spot.


Coral bleaching on the Great Barrier Reef. (ARC Center for Excellence for Coral Reef Studies)

Other hot spots included Mexico, central and northwestern Africa as well as western Australia, Copernicus reported. In contrast, the only area with well-below average temperatures was central Canada.

That 2020 may eclipse 2016 for the dubious title of the warmest year on record is another indication of human influence on the climate.

Currently, there is no declared El Niño event in the tropical Pacific Ocean, which tends to provide a natural boost to global temperatures that are already elevated because of the human-caused buildup of greenhouse gases in the atmosphere. By contrast, the 2016 record occurred during an extremely strong El Niño event.

The NOAA projection, made in mid-March, is based on statistical modeling now that the first quarter of 2020 is off to a near-record warm start, coming in as the second-warmest January-through-March period since instrument records began in 1880.

Both Europe and Asia had their warmest first quarter of the year, based on NOAA data.

In an indication of how high of a fever the Earth is running, NOAA found that February and March were the warmest two non-El Niño months in NOAA’s temperature database, said Derek Arndt, the head of the climate monitoring division at the National Centers for Environmental Information in Asheville, N.C.

NASA and NOAA will release their April temperature rankings in the next two weeks. While the exact rankings may differ from that of Copernicus due to differences in how each group accounts for temperatures in fast-warming but relatively data-sparse regions such as the Arctic and Antarctic, the overall differences are likely to be small, Copernicus noted.

Assuming NOAA ranks April as having global average temperatures above the 20th-century average, it would be the 424th straight month to have that distinction.

In other words, those who are 35 years old and younger have never experienced a cooler-than-average month on Earth.