The year 2019 was the second-hottest year on record as average global surface temperatures followed a long-term upward trend, NASA and the U.S. National Oceanic and Atmospheric Administration reported Jan. 15.
Five of the warmest years recorded since 1880 have all happened since 2015, while nine of the 10 warmest years have occurred since 2005, the agencies found. In 2019, the global annual temperature was 0.98 degrees C or 1.8 degrees F higher than the baseline period of 1951-1980, NASA said.
The United Nation's Intergovernmental Panel on Climate Change has warned that the world needs to ramp up efforts quickly to reduce emissions over the next decade to limit and mitigate the physical impacts of climate change. And on Jan. 15, the World Economic Forum ranked climate change-related concerns as the top five most likely global risks over the next decade. But global emissions have continued to climb and President Donald Trump has started the process for pulling the U.S. from the Paris Agreement on climate change.
At the same time, NASA and NOAA scientists have sided with the vast majority of the scientific community in attributing global warming to human activity, primarily the production of greenhouse gas emissions.
"Every decade since the 1960s has been warmer than the decade previously, and not by a small amount" and that trend is likely to continue, NASA's Goddard Institute for Space Studies Director Gavin Schmidt said in a press call. In a statement, Schmidt also said the trend is "not a fluke due to some weather phenomenon: we know that the long-term trends are being driven by the increasing levels of greenhouse gases in the atmosphere."
On a regional scale, the agencies found that record-high annual temperatures on land were measured in parts of central Europe, Asia, Australia, southern Africa, Madagascar, New Zealand, North America, and eastern South America. Australia, which has been plagued by an abnormally large fire season following hot, dry weather, had an average of 1.52 degrees C above the 1961–1990 average. This exceeded the previous record for the country of 1.33 degrees C set in 2013.
And while Alaska had its warmest year on record, North America more broadly had a milder average. Overall, North America's temperature was 0.90 degrees C above the 1910–2000 average, which is the 14th warmest year in the 110-year continental record.
NOAA recently also reported that 2019 was the second wettest on record for the U.S., easing droughts in some areas even as severe inland flooding across other regions caused about $20 billion in damages.