As the controversy continues, a new avenue of research seems to indicate that humans are indeed responsible for global climate change. It has to do with “energy absorption.”
Researchers studying significant changes in the Earth’s absorption of the sun’s energy concluded that there is less than a one percent chance that the changes that have happened over the last few decades have occurred naturally. Therefore, there is a 99% probability that they are the result of human action.
The long-term stability of the Earth’s climate hinges on a delicate balance between the amount of energy the planet absorbs from the sun and the amount of energy the Earth emits back into space. But that equilibrium has been thrown off in recent years — and the imbalance is growing, according to a recently published paper by researchers from Princeton University in the journal Nature Communications.
The changes to Earth’s energy system have major ramifications for the planet’s future climate and humanity’s understanding of climate change. By demonstrating that the planet’s energy imbalance cannot be explained just by Earth’s own natural variations, the new research is a powerful counter to those who argue that global climate change is not caused by human interventions.
The research also offers important insights into how greenhouse gas emissions and other consequences of human-caused climate change are upsetting the planet’s equilibrium and driving global warming, sea-level rise, and extreme weather events.
“With more and more changes to the planet, we’ve created this imbalance where we have surplus energy in the system,” said Shiv Priyam Raghuraman, a graduate student in atmospheric and oceanic sciences at Princeton and lead author of the study. “That surplus manifests as different symptoms.”
Emissions of carbon dioxide, methane, and other greenhouse gases from human activities trap heat in the atmosphere, meaning the planet absorbs infrared radiation that would normally be released into space. Melting sea ice, changing cloud cover, and differences in the concentration of tiny atmospheric particles called aerosols — all of which are affected by climate change — also mean Earth is reflecting less of the sun’s radiation back into the cosmos.
“There isn’t this equilibrium between energy coming in from the sun and energy going out,” Raghuraman said. “The question is, are these natural planetary variations, or is it us?”
Unfortunately, Raghuraman believes that his research indicates that it is far more likely that it is indeed “us.” He and his team used satellite observations from 2001 to 2020 to determine that Earth’s energy imbalance is growing. They then used a series of climate models to simulate the effects on Earth’s energy system if human-caused climate change was taken out of the equation.
The scientists found that natural fluctuations alone could not explain the trend observed over the 20-year period.
“It was almost impossible — a less than 1 percent probability — that such a large increase in the imbalance was from Earth’s own oscillations and variations,” Raghuraman said.