Satellite confirms NASA's key temperature data: the planet is warming up – and quickly

A very prominent temperature data set from NASA, which stated that the last five years were the hottest ever recorded and that the world had a degree of warming greater than Celsius compared to the late nineteenth century, was reinforced by independent satellite recordings, which seems to indicate that the results are reliable. jogging, scientists reported on Tuesday.

Researchers have found that the pace of climate change may be a little harsher than previously thought, at least in the region of the world where the warming is the fastest, namely its highest latitudes.

"We may have underestimated the amount of heat that he received [the Arctic’s] Said Gavin Schmidt, director of NASA's Goddard Institute for Space Studies, which keeps the temperature data, and co-authored the new study published in Environmental Research Letters.

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NASA's flagship dataset, known as GISTEMP, is one of two systems maintained by US government agencies, the other being managed by the National Oceanic Administration and the United States Government. atmosphere. The two sets of data, as well as several others updated by academic institutions and groups around the world, are based on merging the recordings of thousands of thermometers scattered over the Earth's surface and an increasing volume of ocean-based measurements. from buoys and other instruments.

As the data sets showed not only constant global warming, but also a series of new temperature records, they were further examined, with occasional criticisms of the high-profile findings and the way in which of which they are assembled. However, the research groups maintained that their methods are valid and that the different records agree considerably more than they disagree, suggesting that the warming trend that they show is more or less correct .

Access NASA's Aqua satellite, which has been in orbit since 2002, equipped with an infrared device capable of independently measuring the Earth's surface temperatures, and with a higher resolution than the one that characterizes the satellite. Set of climate data from NASA. .

The temperature record provided by the satellite, which currently extends from 2003 to 2018, corroborates NASA's finding that 2016 was the hottest year ever recorded and that, so Generally, the warming trend continued when surface thermometers claimed, concludes the study conducted by Joel Susskind of NASA.

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"What you get is a really impressive match between the trends observed in this satellite product totally independent of surface temperatures and the interpretations of weather stations," said Schmidt, one of Susskind's three partners. -Authors.

Here is a figure from the study that shows how NASA data for the years 2003 to 2017 correspond to the findings of the atmospheric infrared sounder on the Aqua satellite, or AIRS, and how these data in turn follow three other sets of global temperature data:

"What you get is a really impressive match between the trends observed in this satellite product totally independent of surface temperatures and the interpretations of weather stations," said Schmidt, one of Susskind's three partners. -Authors.

Here is a figure from the study that shows how NASA data for the years 2003 to 2017 correspond to the findings of the atmospheric infrared sounder on the Aqua satellite, or AIRS, and how these data in turn follow three other sets of global temperature data:

Notably, AIRS sometimes shows a warmer response than the NASA data set, and particularly in the Arctic, a region where measurements are scarce and the warming is fastest. It is even shocking to note that in the Barents and Kara seas in the Arctic, warming is at a rate of 2.5 degrees Celsius, or 4.5 degrees Fahrenheit, per decade.

This suggests that the Earth as a whole could warm up faster than NASA had announced so far, not more slowly.

"These results should help dispel the lingering fears that modern warming is somehow due to the location of sensors in urban heat islands or other surface measurement errors," Zeke said. Hausfather, a researcher at the University of California at Berkeley. on another set of temperature data – called Berkeley Earth – and commented on the new study, with which he was not involved.

"AIRS satellite data captures the entire surface of the planet and shows that our surface measurements slightly underestimate the rate of global warming," he said.

The study also confirms "that the Arctic is heating up much faster than the rest of the world and that a correct estimate of temperatures in the region is important to understand what is happening in the world in its entirety. together, "said Hausfather.

The new study "confirms (again) from an independent source that surface temperature records over the last twenty years are robust," added Ed Hawkins, a researcher in climatology at the University of Reading in Grande Britain, by e-mail.

The methodologies used to calculate the Earth's temperature are constantly being improved – and the datasets are constantly being updated with the most up-to-date information. There will be lively debates about how to deal with some of the issues related to this process, including the fact that cities tend to be hotter than the countryside and that records are much more numerous and reliable today than in the past. at the end of the 19th century. or a bit before, when the datasets start.

But the new study suggests that none of this weakens the main conclusion: warming is underway; and the Earth continues to reach record temperatures, at least in the context of the past 140 years or so.

"Despite all the problems, the schemes are not just qualitatively correct, they are almost quantitatively correct too," said Schmidt.

Correction: An earlier version of this article incorrectly stated that the AIRS satellite temperature data set had started in 2013 rather than in 2003. The error has been corrected.