NASA Study Proves We're Causing Climate Change

Our Daily Planet

While scientists have long agreed that human activity was the biggest driver of climate change, there hasn't yet been evidence from direct observation (the gold standard of scientific research) until now.

NASA has completed the first study of its kind, which has calculated the recent causes of climate change by directly observing satellite data. These observations are in line with what models have been suggesting for years: that the increase in greenhouse gases and other pollution in the atmosphere from burning fossil fuels has been the biggest driver of climate change.

Why This Matters

While there have been other types of evidence to demonstrate anthropogenic climate change, this is the first time scientists have been able to track how humans are directly changing Earth's energy balance on the global scale.

Still, climate denial has run rampant through the US government. Currently, there are 139 elected officials in the US Congress that refuse to admit to the existence of climate change. Many climate deniers maintain that there is not enough data to link humans to climate change. This study fully discredits that premise.

Observing Multiple Factors

It's widely accepted that an increase of heat-trapping gases in the air, like CO2 and methane from burning fossil fuels, has caused the earth to heat up. And, there is observational evidence that the amount of CO2 in the atmosphere has increased over the last century, which should cause the planet to warm. However, given the difficulties of measuring heat trapping on Earth from space, there hadn't been observational evidence of the two factors (increasing CO2 and rising temperatures) in tandem until now.

This NASA animation is a simplified illustration of Earth's planetary energy balance. The energy budget is balanced between incoming (yellow) and outgoing radiation (red). Natural and human-caused processes affect the amount of energy received as well as the amount emitted back to space.

Before, satellite observations of heat on Earth could only find the number of total radiation changes, rather than the individual components. But NASA was able to calculate the changes in heat trapped in the Earth's atmosphere by taking satellite observations and using a "radiative kernel" to analyze them, which allowed the researchers to understand what factors influenced the emission and trapping of heat.

The agency found that from 2003 through 2018, radiative forcing has increased 0.5 watts per meter-squared (W/m2), which is ten times all the energy used by humans in a single year.

This graph shows the heating imbalance in watts per square meter relative to the year 1750 caused by all major human-produced greenhouse gases: carbon dioxide, methane, nitrous oxide, chlorofluorocarbons 11 and 12, and a group of 15 other minor contributors. Today's atmosphere absorbs about 3 extra watts of incoming solar energy over each square meter of Earth's surface. According to NOAA's Annual Greenhouse Gas Index (right axis) the combined heating influence of all major greenhouse gases has increased by 43% relative to 1990. Graph by NOAA based on data from NOAA ESRL.

Though these results are not surprising, Dr. Brian Soden, co-author of the study and professor of Atmospheric Sciences at the University of Miami's Rosenstiel School of Marine and Atmospheric Science, summed up the importance of the study in an interview with CBS:

In reality, the observational results came in just as predicted by the theory. There is no surprise in the results, but rather it’s really more of "dotting the i's and crossing the t's" on anthropogenic [human-caused] climate change. It closes that last link between rising CO2 levels and planetary warming.


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