Why does the earth absorb more heat than it releases into space
The earth is getting warmer. Oceans like the Pacific are warming especially. A view of the planet from the “International Space Station”
Quayle: pa/ZUMAPRESS.com/NASA
US researchers have investigated Earth’s energy balance: Our planet is absorbing far more heat than it is giving out. The extent of the increase is “unprecedented”. There are two reasons for the imbalance – the greenhouse effect is just one of them.
dAccording to American scientists, the Earth has absorbed a lot of heat in the last 15 years. Between 2005 and 2019, Earth’s so-called energy imbalance nearly doubled, researchers from the US climate agency NOAA and the space agency NASA said in the journal. “Geophysical Research Papers” Together.
This trend was mainly due to an increase in absorbed solar radiation due to reduced reflectivity. clouds and sea ice traced back. At the same time, long-wave radiation from Earth into space, through which energy and thus heat is released, has been reduced, among other things, causing more greenhouse gases in the atmosphere.
It is based on a sensitive energetic balance on Earth: on the one hand, the Sun’s rays are absorbed by the atmosphere and the Earth’s surface, on the other, the Earth emits. infrared radiation in space From.
If both processes are balanced, then the energy balance is balanced. A positive energy balance means that the Earth is warming. Since about 90 percent of this additional energy is absorbed by the oceans, the water in the oceans gets warmer.
Energy imbalance can also be influenced by natural factors. According to the scientists, the Pacific Decade Oscillation (PDO) in particular may have played a role. With that, the temperature of the change surface water in the pacific Clearly – a particularly hot phase such as that between 2014 and 2020 contributes to the fact that significantly more solar radiation is absorbed by Earth.
“It’s probably a mix of human drivers and internal (Earth) change,” said study lead Norman Loeb. Human and natural factors combined have caused “heat that is causing a significant change in Earth’s energy imbalance. The magnitude of the increase is unprecedented.”
Loeb stressed that the study is only a snapshot of long-term climate change and that it is not possible to predict with certainty what Earth’s energy budget may look like in the coming decades.
