NASA and the U.S. National Oceanic and Atmospheric Administration (NOAA) have declared the 2010s the hottest 10 years on record, with 2019 the second-warmest ever, findings confirmed by climate-related devastation around the globe.
After rigorously crunching through a gargantuan amount of surface temperature data from the past decade, the research team also determined that the past five years “each rank among the five hottest since record-keeping began,” reports Washington Post.
NASA and Columbia University research scientist Kate Marvel told the Post that “no individual hot year—or hot day or hot season, for that matter—is by itself evidence for climate change.” However, the decidedly upward trend in surface temperatures in every decade since the 1960s, with the latter half of the 2010s being especially warm, proves that “the planet is statistically, detectably warmer than before the Industrial Revolution”.
Marvel added: “We know why. We know what it means. And we can do something about it.”
“These trends are the footprints of human activity stomping on the atmosphere,” Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, told the New York Times.
Noting the absence of caveats and caution that would be typical of scientists reporting on their data, the Times describes an “exhaustive” collection of temperature data “gathered at sea from ships and buoys, and on land from tens of thousands of observing stations coordinated by governmental meteorological agencies,” followed by a rigorous “combing” of the data for errors and bias.
Working with the same data set, but independently, NASA and NOAA also took into account “the contribution of natural influences, or forcings, on climate, like volcanic eruptions that can temporarily cool the atmosphere or regular changes in Earth’s orbital cycle,” the paper adds.
Accounting for those temporary disturbances still left a “massive discrepancy,” Schmidt said, a gap whose vastness told the researchers beyond any doubt that “natural forcings are not capable of explaining the trends we’ve seen since the 19th century.”
With the burning of fossil fuels unambiguously identified as the culprit in driving up the annual global average surface temperature “at an average rate of about 0.18°C/0.32°F per decade,” writes the Post, most nations have committed to try to limit average global warming to 1.5°C above preindustrial levels, “in an effort to head off catastrophic sea level rise, ever-deadlier extreme weather events, and other climate-related disasters.” However, “hitting that ambitious target would require a rapid, transformational shift away from fossil fuels that has yet to materialize.”
And while global greenhouse gas emissions reached an all-time record in 2019, many places around the world have already warmed by at least 2.0°C, crossing a threshold that “scientists and policy-makers have identified as a red line if the planet is to avoid catastrophic and irreversible consequences.”
The Post recaps some of the greatest hits of the 2019 severe weather season, including the pummeling of Mozambique by two back-to-back spring cyclones, which killed hundreds; August’s Hurricane Dorian, which devastated the Bahamas and the eastern United States and Canada; and “a tragic and terrifying December in Australia, with bushfires proliferating amid heat and drought” and the national average high temperature smashing all records with “a blistering 107.4°F/41.9°C” December 18.
Meanwhile, “reports from the UN Intergovernmental Panel on Climate Change last year detailed how climate change is already threatening food and water supplies, increasing the threat of droughts and floods, killing coral reefs, supercharging monster storms, fueling deadly marine heat waves, and contributing to record losses of sea ice,” the Post adds. The year also brought news that melting Arctic permafrost “may already be a net source of atmospheric carbon, a shift that could accelerate global warming.” And fires raged in the Amazon, raising concerns that a critical storehouse for carbon may be on the verge of devolving into a far less carbon-dense savannah ecosystem, though scientists said there was still time to avert that outcome.