NASA Analysis: Road Transportation is Key Driver of Climate Warming

The on-road transportation sector releases significant amounts of carbon dioxide, black carbon, and ozone—all substances that cause warming.

In contrast, the industrial sector releases many of the same gases, but it also tends to emit sulfates and other aerosols that cause cooling by reflecting light and altering clouds. Credit: NASA GISS/Unger

For decades, climatologists have studied the gases and particles that have potential to alter Earth's climate. They have discovered and described certain airborne chemicals that can trap incoming sunlight and warm the climate, while others cool the planet by blocking the Sun's rays.

Now a new study led by Nadine Unger of NASA's Goddard Institute for Space Studies (GISS) in New York City offers a more intuitive way to understand what's changing the Earth's climate. Rather than analyzing impacts by chemical species, scientists have analyzed the climate impacts by different economic sectors.

Each part of the economy, such as ground transportation or agriculture, emits a unique portfolio of gases and aerosols that affect the climate in different ways and on different timescales.

"We wanted to provide the information in a way that would be more helpful for policy makers," Unger said. "This approach will make it easier to identify sectors for which emission reductions will be most beneficial for climate and those which may produce unintended consequences."

Unger's model finds that in 2020 (left), transportation, household biofuels and animal husbandry will have the greatest warming impact on the climate, while the shipping, biomass burning, and industrial sectors will have a cooling impact.

By 2100 (right), the model finds that the power and industrial sector will become strongly warming as carbon dioxide accumulates. Credit: NASA GISS/Unger

In a paper published online on Feb. 3 by the Proceedings of the National Academy of Sciences, Unger and colleagues described how they used a climate model to estimate the impact of 13 sectors of the economy from 2000 to 2100. They based their calculations on real-world inventories of emissions collected by scientists around the world, and they assumed that those emissions would stay relatively constant in the future.

Unger's analysis is one of the first of its kind to incorporate the multiple effects that aerosol particles can have on clouds, which affect the climate indirectly. Credit: NASA's Johnson Space Center

You can read the full article on the NASA website - Click here...