“The level of increase is unprecedented. The Earth is warming faster than expected,” said Norman Loeb, a scientist at NASA and the lead author of the study published this week in the journal Geophysical Research Letters.
By utilizing satellite data, researchers from NASA and the National Oceanic and Atmospheric Administration (NOAA) measured the so-called energy imbalance that the Earth is experiencing. This is the difference between the amount of energy the Earth absorbs from the sun and the amount of heat that can be emitted or radiated back into space. Accordingly, scientists found that the Earth is currently absorbing more heat than it is losing. This is considered a preliminary step leading to global warming.
The study shows that the aforementioned energy imbalance has nearly doubled from 2005 to 2019. The amount of energy being ‘trapped’ by the Earth is so large that it is equivalent to every person on Earth using 20 electric kettles at the same time.
According to scientists’ estimates, the Earth absorbs about 240 watts per square meter of energy from the sun. The oceans absorb most of that heat, accounting for about 90%.
At the beginning of the study period (i.e., in 2005), the Earth radiated back to space about 239.5 watts – creating a difference of about half a watt. However, by 2019, the difference between the energy absorbed by the Earth and the energy radiated into space had nearly doubled – to about 1 watt per square meter.
The biggest question raised is what has driven the excessive heat accumulation.
The study indicates that the decline in cloud and sea ice cover, which reflects solar energy back into space, has caused the Earth to retain more heat. Concurrently, the increase in greenhouse gases emitted by humans, such as methane and carbon dioxide, as well as water vapor, has exacerbated the situation.
The period studied also overlaps with climate fluctuations, which could play a significant role in accelerating heat retention. It includes the strong El Niño event from 2014 to 2016, which led to unusually warm sea temperatures across the oceans. This additional heat, especially in the oceans, will mean much more intense storms and marine heatwaves.
“This is not good news,” warned study lead author Norman Loeb.
Source: Washington Post