In November, BioScience published a Warning article stating "we declare, with more than 11,000 scientist signatories from around the world, clearly and unequivocally that planet Earth is facing a climate emergency" and that an "immense increase of scale in endeavors to conserve our biosphere is needed to avoid untold suffering due to the climate crisis".[1]
"Vital Signs of the Planet" as presented by NASA on 31 December 2019[2]
NOAA's National Centers for Environmental Information (NCEI) and the WMO reported that 2019 was the second hottest year in its 140-year climate record—0.04°C (0.07°F) cooler than 2016—with the U.K. Met Office ranking it among the three hottest.[3]
NOAA also reported that ocean heat content—the amount of heat stored in the upper levels of the ocean—was the highest ever recorded.[3]
NOAA also reported that both the Antarctic and Arctic oceans recorded their second smallest average annual sea-ice coverage during the 1979–2019 period of record.[3]
The WMOGlobal Atmosphere Watchin-situ observational network showed that carbon dioxide (410.5±0.2 ppm), methane (1877±2 ppb) and nitrous oxide (332.0±0.1 ppb) reached new highs in 2019, respectively constituting 148%, 260% and 123% of pre-industrial levels.[4]
The fire season in Sakha (Siberia) was unprecedented in the 20-year MODIS record in terms of an earlier start and northern extent, with some fires burning only about 11 km from the Chukchi Sea.[5] From March through June, the burned area was greater than 2.9 times the 20-year mean.[5]
The Rhodium Group estimated that China contributed over 27% of total 2019 global greenhouse gas emissions (14 of 52 gigatons), surpassing the emissions of all OECD countries combined, though trailing them in per capita emissions; China was followed by the U.S. (11%), India (6.6%), Europe-27 (6.4%).[6]
1 February 2022: a study published in PLOS Climate reported that, in 2019, 57% of the global ocean surface recorded extreme heat, compared to 2% during the Second Industrial Revolution, and that, between the 1980s and 2010s, the global mean normalized heat index increased by 68.23%.[7] Researchers stated that "many parts of the subtropical and midlatitude regions have reached a near-permanent extreme warming state".[7]
In 2019, Amazon and Global Optimism co-founded The Climate Pledge whose signatory companies pledge net-zero carbon emissions by 2040, stimulating investment in low-carbon products and services.[8]
In March, 16-year-old Swedish climate activist Greta Thunberg was nominated for the Nobel Peace Prize, also receiving a nomination the following year.[9]
In Norway, electric cars comprised 54% of all new vehicle sales for 2019, making it the first country to have sold more electric cars than petrol, hybrid, and diesel engines in a year.[12] The government planned to ban the sale of petrol and diesel cars by 2025.[12]
The consensus among research scientists on anthropogenic global warming grew to 100%, based on a review of 11,602 peer-reviewed articles on "climate change" and "global warming" published in the first 7 months of 2019.[14]
A 2019 survey indicated a clear majority of people around the world think climate change is happening and that it is all or partly down to human actions.[15] However, 17% of Americans polled agreed that "the idea of manmade global warming is a hoax that was invented to deceive people", only Saudi Arabia and Indonesia having a higher proportion of people doubtful of manmade climate change.[15]
In January, the World Economic Forum listed top 10 risks by likelihood (extreme weather events as #1, failure of climate change mitigation and adaptation as #2, man-made environmental damage and disasters as #6) and by impact (failure of climate change mitigation and adaptation as #2, extreme weather events as #3, man-made environmental damage and disasters as #9).[16]
Herring, Stephanie C.; Christidis, Nikolaos; Hoell, Andrew; Hoerling, Martin P.; Stott, Peter A., eds. (January 2021). "Explaining Extreme Events or 2019 From a Climate Perspective"(PDF). AMetSoc.net. American Meteorological Society. Archived(PDF) from the original on 27 January 2021.
