Global heating had doubled since 2005, NASA says
Global heating has doubled since 2005 and the Earth is now trapping an unprecedented amount of heat. New research from NASA and the National Oceanic and Atmospheric Administration find. This has contributed to the more rapid warming of oceans, air, and land.
The findings were published in the journal Geophysical Research Letters. “The Earth is warming faster than expected.” “The magnitude of the increase is unprecedented,” said Norman Loeb, a NASA scientist and lead author of the study.
The researchers used satellite data to measure Earth’s energy imbalance; the difference between the energy Earth absorbs from the sun, and the energy it sheds or radiates back out into space.
When there is a positive imbalance; Earth absorbing more heat than it is losing; it is the first step toward global heating, said Stuart Evans, a climate scientist at the University at Buffalo. “It’s a sign the Earth is gaining energy.”
The study found out that the positive imbalance has doubled between 2005 and 2019, “It is a massive amount of energy,” said Gregory Johnson, an oceanographer for NOAA’s Pacific Marine Environmental Laboratory. Johnson said the energy increase is equivalent to four detonations per second of the atomic bomb dropped on Hiroshima, or every person on Earth using 20 electric tea kettles at once. “It’s such a hard number to get your mind around.”
The planet takes in around 240 watts per square meter of energy from the sun. At the beginning of the study period, in 2005, it was radiating back out about 239.5 of those watts. And creating a positive imbalance of about half a watt.
The researchers found by 2019, that gap had nearly doubled to about 1 full watt per square meter.
Oceans absorb most of Earth’s heat, about 90 percent. After comparing satellite data to temperature readings from a system of ocean sensors, the researchers found a similar pattern. The agreement between the data sets surpassed expectations, Loeb said, calling it the “nail in the coffin” for the imbalance results.
“The fact that they used two different observational approaches and came up with the same trends is pretty remarkable,” said Elizabeth Maroon, a climatologist at the University of Wisconsin at Madison unaffiliated with the study. “It lends a lot of confidence to the findings.”
The cause of increased global heating
The study finds human activities and decreases in cloud cover and sea ice are to blame. Cloud cover and sea ice help to reflect solar energy back into space. Human activities are contributing through the emission of methane and carbon dioxide which traps much heat in the Earth creating an imbalance. Researches said it is difficult to discern human-induced changes from cyclical variations in the climate.
The study period overlapped with fluctuations in the climate that played a significant role in the acceleration such as the El Niño event from 2014 to 2016, which led to unusually warm waters. The Pacific Decadal Oscillation is a longer-term, El Niño-like fluctuation, and around 2014 that also switched from a “cool” phase to a “warm” phase.
However, Johnson doesn’t let humans off the hook. “We’re responsible for some of it,” he said.
Kevin Trenberth, a scholar at the National Center of Atmospheric Research, said the results aren’t surprising given the climactic variations of today. But 15 years is not enough time to establish a trend, he added.
“Certainly you’d like to see another 10 years or something like that to see how this behaves,” he said. “The question is: Will this continue?”
That too is unclear, Johnson said. The imbalance could shrink in some years compared to others, he said, but the general trajectory appears to be upward, especially if the Pacific Decadal Oscillation stays in a warm phase.
“The longer we observe it,” he said, “the more certain we become of the trend.”
Regardless of the magnitude or reasons for the accelerated imbalance, the fact that it is positive is crucial, said Trenberth. “It’s the sign that matters here,” he said. “The fact that it’s positive means that global heating is happening.”
That extra heat, especially in the oceans, will mean more intense hurricanes and marine heatwaves.
“I hope the heating doesn’t keep going at this clip,” Loeb said. “It’s not good news.”