After three years, the refrain is starting to get old. It happened in 2014, and again in 2015.
Now, both NASA and the National Oceanic and Atmospheric Administration (NOAA) have announced that the year 2016 marked Earth’s warmest year on record—again.
According to NOAA, global land and ocean surface temperatures were 0.94° Celsius, or 1.69° Fahrenheit, above the 20th century average. NASA independently found that global average surface temperatures in 2016 were 0.99° Celsius, or 1.78° Fahrenheit, warmer than the mid-20th century average.
The news broke just as confirmation hearings commenced for Scott Pruitt, U.S. President-elect Donald Trump’s choice for head of the Environmental Protection Agency. Pruitt played a key role in legal battles against President Obama’s climate change policies. He is also an ally of the fossil fuel industry, which an overwhelming majority of experts blame for pumping out dangerous volumes of carbon dioxide and other greenhouse gases.
Climate scientists agree that El Niño events—which boost global temperatures due to a band warm of Pacific Ocean water releasing water vapor into the atmosphere—contributed to average temperature increases in 2016. However, they say that having a record broken three years in a row is a highly unusual occurrence: a sign that something greater than El Niño is brewing. NOAA reported that the only other instance of a similar three-year streak was in 1939, 1940 and 1941. Even so, 1941 now ranks as merely the 37th-warmest year on record.
The situation is most dire the Arctic, where sea ice has been melting and communities have been fighting coastal erosion.
Here are Justin Gillis and John Schwartz, reporting for The New York Times:
But Arctic people were hardly alone in feeling the heat. Drought and starvation afflicted Africa . On May 19, the people in the town of Phalodi lived through the hottest day in the recorded history of India, 123.8 degrees Fahrenheit.
El Niño has now ended, and climate scientists almost universally expect 2017 to be cooler than the year before. But the scale of the heat burst has been startling to many of the experts, and some of them fear an accelerated era of global warming could be at hand over the next few years.
What’s more, in 2016 sea ice levels in the Arctic fell to the lowest October, November, and December levels ever, and air temperatures in November were 36° Fahrenheit (20° Celsius) higher than normal —three or four standard deviations away from the mean, according to a scientist who spoke with NOVA—across the region. But melting sea ice alone isn’t the problem. Here’s Brad Plumer, writing for Vox:
One important thing to note here is that we’re talking about sea ice that’s already floating in the ocean—when it melts and disappears, it doesn’t directly affect global sea levels. (The ice was already displacing its own weight; much like when an ice cube melts in a drink, it doesn’t raise the water level.) So the disappearance of sea ice won’t, on its own, flood our coastal cities.
But melting sea ice can have important indirect effects. For instance : As more and more sea ice in the Arctic vanishes, more of the ocean underneath is exposed to sunlight. Because the ocean is darker than the bright ice, it absorbs more heat—and the broader region heats up more quickly. (This “feedback” effect appears to be quite significant in the Arctic.)
Even Klawok, Alaska recorded its highest-ever temperature 21.6° Celsius (71° Fahrenheit) on March 31 of last year. Climate scientists will be monitoring regions and cities like Klawok that are experiencing dramatic changes in the coming year, as 2017 will foretell much of what to expect (and what to prepare for) as regards to our rapidly transforming home.