365 Days of Climate Awareness 174 – 2020 State of the World Climate

2020 World Climate Data

• Global atmospheric CO₂ concentration: 412.44 ppm, +2.37 ppm from 2019
• Surface air temperature anomaly: +0.98°C/1.76°F, 2^nd all-time 1880-2021
• Precipitation 22.5 (0.4 in) mm below 1961-1990 global average 1033 mm (40.7 in)
• Global mean sea level 56.55 mm above 1993-2008 average, +0.96 mm from 2019
• Antarctic ozone hole: max. area 24.8 million km²; minimum O₃ 94 DU (Dobson Units)
• ENSO: Weak El Niño early, neutral in summer, weak La Niña late
• NAO: Negative early (cooler in southeastern US and northern Europe; warmer in northeastern Canada and southern Europe), then variable

Larger Version

Global Conditions

• Above-average temperatures:  The Caribbean; the Amazon Basin and western South America; northwestern, eastern and the horn of Africa; western Indian Ocean islands; Europe (record warmth); Russia; Siberia; Mongolia; Japan; central and eastern China; Australia
• Below-average temperatures: Colombia; eastern Brazil; northern Argentina; southern and central western Africa; India; Pakistan; Afghanistan; Iran
• Above-average precipitation: The Amazon Basin; eastern Brazil; central and eastern Africa; northwestern Russia; central Siberia; eastern Mongolia; India; Pakistan; southeastern Iran; northwestern and southeastern Australia
• Below-average precipitation: Western, central and southern South America; western Indian Ocean islands; the Iberian Peninsula; France; Germany; the Baltic states; Turkey; the Middle East; the Caucasus region; southwestern Australia

Arctic Siberia experienced the highest temperature anomalies of the Eurasian landmass, with its firth-warmest summer and warmest autumn on record, with many areas averaging more than 5°C/9°F above the long-term average for the year. The season’s record heat extended west through the Baltic states into Scandinavia. Northwestern Russia went through an early summer heat wave featuring temperatures more than 20°C/36°F above average. The extreme heat was not matched by precipitation patterns, however, with positive rain and snow anomalies stretching from eastern Scandinavia southeast across Asia to the region of Japan.

A severe marine heat wave occurred in the Northeast Pacific during the middle and latter half of 2020, akin to “the Blob” of 2013-15. A marine heat wave (MHW) is defined as a region of the ocean with persistent (five days or longer) very high temperatures (above the 90^th percentile). In late 2019 such a warm patch developed in the northeastern corner of the Pacific, and in 2020 came to stretch from the Gulf of Alaska to Hawaii. The event impacted fisheries—pushing tuna and other large species toward land, increasing recreational catches--and led to harmful algal blooms of the west coasts of Canada and the United States.

2020 Sea Surface Temperatures (SSTs) from the Pacific Ocean: (a) June-July-August; (b) September-October-November. Note warm patch in the NE Pacific in both, and developing La Niña in (b).  Larger Version

The ocean appears to have a “memory” of these events, where the extremely warm surface water cools enough to descend to intermediate depths, but retains enough anomalous warmth relative to the surrounding water masses to increase the heat content of the ocean. The northeastern Pacific is warming, and due to its increasing stratification, is likely to experience more of these large heat waves in the future.

Tomorrow: 2021 state of the climate, North America.

Be brave, and be well.