AUSTIN (KXAN) — While it’s now common knowledge that man-made greenhouse gas emissions trap more heat at the Earth’s surface and cause global temperatures to rise, it’s never been proven 100% by conclusive, direct and observational data.
But that’s now changed.
In a first-of-its-kind study, academic researchers along with NASA scientists are quantifying the direct impact that human activity is having on our climate system — and proving human activity is to blame for recent warming trends.
Before the Industrial Revolution, the Earth’s climate was, for a large amount of time, in a relatively stable, harmonious stasis where heat energy coming into the atmosphere was equivalent to energy going out. Note that the sun brings incoming heat energy, and the Earth itself gives off outgoing energy to maintain balance.
There is a natural greenhouse effect caused by the aerosols and clouds in our atmosphere, where some of the outgoing energy trying to get back out to space is reflected back to the surface, or trapped. This is the reason Earth’s climate is relatively warm and livable.
But beginning in the Industrial Revolution in the 1800s, humans began putting massive amounts of additional greenhouse gases into the atmosphere, “thickening the blanket” around the Earth and trapping more of that heat energy at the surface instead of allowing it to radiate out to space. This is causing the planet to warm unnaturally.
While there are well-established observations of greenhouse gases and surface temperatures increasing in tandem, there has never been a global measure of this “energy balance” referred to above that was able to isolate human-caused changes from the natural climate system.
The study used a special method to isolate human climate forcing, and found that it has increased from 2003-2018. In other words, human activity made the blanket around Earth thicker, and better at trapping heat.
Furthermore, the authors were able to show that the increase in heat-trapping gases from human activity were responsible for nearly all of the long-term growth in the energy in/out imbalance during that period, and thus responsible for nearly all of the rising temperatures.
This serves as the first direct, observational evidence that human activity has affected the Earth’s energy budget and led to global warming.