Last year said to be fourth-warmest since 1800s and sea levels the highest on record
The gases heating the planet in 2018 were higher than humans have ever recorded, according to an authoritative report published by the American Meteorological Society and compiled by the US government.
Greenhouse gas levels topped 60 years of modern measurements and 800,000 years of ice core data, the study found. The data used in the 325-page report is collected from more than 470 scientists in 60 countries.
The global annual average for carbon dioxide – which is elevated because of human activities like driving cars and burning fuel – was 407.4 parts per million, 2.4ppm higher than in 2017. The warming influence of CO2 and other gases in the atmosphere is now nearly 43% stronger than in 1990.
While 2018 did not break global heat records, it was the fourth warmest year since the mid-to-late 1800s. Temperatures were 0.3C to 0.4C higher than the average between 1981 and 2010. Only 2015, 2016, and 2017 were hotter.
Sea levels were the highest on record, as global heating melted land-based ice and expanded the oceans. Sea surface temperatures were also near a record high.
As the National Oceanic and Atmospheric Administration put it, the report “found that the major indicators of climate change continued to reflect trends consistent with a warming planet”.
Arctic and Antarctic sea ice extent was near a record low, and glaciers continued to melt and lose mass for the 30th consecutive year in a row. Mexico reported its third warmest year in its 48-year record, and Alaska reported its second warmest in its 94-year record. Australia had its third warmest year since 1910, with a rapidly intensifying and expanding drought and significant fires.
Europe was a hotspot, with its second warmest year since at least 1950. Several countries set or neared heat records, including France, Italy, Serbia, Croatia, Greece, Bosnia and Herzegovina. In July, Sweden saw its highest ever monthly temperature of 22.5C in Stockholm. And in late July and early August, France had a heatwave with temperatures soaring to above 40C.
With extreme heat and severe droughts, Lithuania and Latvia each declared a state of emergency. Germany saw related losses of $3.4bn, and Sweden and Greece had unprecedented wildfires. Low water levels in the Rhine and Danube rivers made it harder to transport goods and run power plants.
Despite the recent massive wildfires in the Arctic and the US, 2018 fire activity around the globe was actually the lowest on record. That is because humans have turned the savannahs that have burned frequently into agricultural areas.
Hawaii saw a new US record for precipitation over 24 hours, at 1262 mm at Waipā Gardens in Kauai, and India set a new world record for three-day rainfall of 710.2mm in its Iduki district.
In the US, there were 14 weather and climate events in the US that each caused over $1bn in damage – the fourth highest since records began in 1980. Hurricane Michael was the fourth strongest to ever hit the continental US, killing more than 30 people and costing $15-20bn in damages.
The tropics neared a record for the number of Category 5 tropical storms, with 11 storms reaching that intensity. In the western North Pacific, super typhoon Mangkhut killed 160 people and cost $6bn, and tropical storm Son-Tinh killed 170 in Vietnam and Laos.
The Caribbean saw coral reef bleaching and South America experienced seven extreme snowfall events.
Heat-trapping gases broke records in 2018, climate report finds