The worrying change that has affected the delicate energy balance of the Earth
Article by: Andacs Robert Eugen, on 19 July 2022, at 10:02 am Los Angeles time
Our living planet is unique among all that mankind has managed to explore so far in the Universe. From our axial tilt, which prevents extreme temperatures, to our position in the habitable zone of the galaxy, life on Earth depends on many finely balanced and interconnected cycles that work together to determine exactly the circumstances we need for life to thrive.
One of these cycles is the delicate energy system of the Earth - the energy received from the Sun and that released by the planet. This cycle dictates all planetary climate systems. On Mars, it is believed that the seasonal change in energy imbalance is considered to be the cause of the famous dust storms of gigantic proportions on the planet.
At least for a while, before the 1750s, this fluctuating energy cycle on Earth was relatively balanced. But now there is an imbalance that has surprisingly doubled in just 15 years.
"The net energy imbalance is calculated by analyzing the amount of heat absorbed by the Sun and the amount of heat that can be radiated back into space," explains atmospheric researcher Kevin Trenberth of the National Center for Atmospheric Research.
"It is not yet possible to directly measure the imbalance, the only practical way to estimate it is through an inventory of energy changes."
Trenberth and the physicist of the Chinese Academy of Sciences, Lijing Cheng, analyzed data from all components of the climate system: land, ice, ocean, and atmosphere between 2000 and 2019, to make an inventory of these changes.
The Earth's atmosphere reflects almost a quarter of the energy that hits it, unlike the Moon, which takes over the entire impact of solar energy, which leads to surface temperatures of about 100°. Most of this energy is then absorbed by the Moon and radiated back into space in the form of infrared or heat radiation.
Again, it is the atmosphere that changes this process here on Earth. Some molecules in our atmosphere capture heat before it reaches space and continues to retain it. Unfortunately for us, these are the greenhouse gases, which have effectively enveloped the planet in a too fluffy blanket in the upper atmosphere.
This extra captured energy not only changes where it ends up but also has an impact on the environment on the way to the final destination, the researchers explain in their paper.
"It is vital to understand the net gain of energy, how much it is, and where heat is redistributed within the Earth's system," they write. "How much heat could be moved where it can be repelled from Earth by radiation to limit warming up?".
While everyone has focused mainly on rising temperatures, this is just a result of this extra energy. Only 4 percent of it goes to rising land temperatures and another 3 percent goes to melting ice, Trenberth and Cheng calculated.
They found that almost 93% of this amount is absorbed by the ocean, and we are already witnessing the unpleasant consequences.
Although less than 1% of the excess energy circulates in the atmosphere, it is enough to directly increase the severity and frequency of extreme weather events, from droughts to floods.
According to Trenberth and Cheng, too much information is still missing to claim that we have a comprehensive model of the Earth system that predicts exactly specific results in the medium and long term.