Science at the Intersection of Air Quality and Climate Change

Smog over New York. Credit: NASA

The atmosphere is a stew of gases and particles. Some affect climate. Others degrade air quality and threaten human health. Some do both. Some do neither. Many of them interact with and affect one other.

Ozone, for example, causes respiratory problems near the surface, but also functions as a greenhouse gas. Black carbon aerosol particles do the same, and also contribute to heart disease.

Other pollutants — notably sulfates and nitrates—create health problems but simultaneously reflect incoming sunlight and cool the climate. Some, like nitrogen oxide, are precursors to ozone, but also affect the abundance of the light- scattering pollutants that cool the climate.

All of this adds up to a question that keeps some climatologists up at night: Is it possible to reduce emissions of toxic air pollutants in a way that will mitigate global warming, or at least not make it worse?

For example, reducing black carbon has the potential to improve health and reduce global temperatures by as much as a degree. On the other hand, reducing sulfates—which industries often emit along with black carbon—could negate any reduction in warming that pollution controls might produce. (These are just a few examples from the dozens of gases and particles that scientists have to factor in tabulating Earth’s energy budget.)

Almut Arneth, a researcher from Lund University in Sweden, and colleagues, including NASA climatologist Nadine Unger, considered the question recently in a “perspectives” piece in Science. You can read the full paper here (though you may need to brush up on your atmospheric chemistry to understand the details). Unger and her coauthors sum the complicated situation up this way:

“Given the toxicity of pollutants, the question is not whether ever stricter air pollution controls will be implemented, but when and where. The jury is out on whether air pollution control will accelerate or mitigate climate change. Still, the studies available to date mostly suggest that air pollution control will accelerate warming in the coming decades.”

If that’s correct, not only do we have a bigger climate problem on our hands than we may have thought, but some will surely misinterpret the finding by concluding that we ought to continue polluting—or even ramp up the emission of certain pollutants with geoengineering—to stave off climate change, a point that NASA climatologist Gavin Schmidt made recently on RealClimate.

–Adam Voiland, NASA’s Earth Science News Team

5 thoughts on “Science at the Intersection of Air Quality and Climate Change”

  1. I am brasilian, I from Cruzeiro do Sul – Acre. I like of space and very beutyful image the space. I need bay in space. thenks very muth.

  2. What is the impact of the increased power consumption of humanity on the atmospheric temperature? For example, a high percentage of the electrical energy used in lighting or of fuel energy in automobiles is converted into heat rather than light or work. How is this additional heat energy in the atmosphere impacting global temperatures?

  3. Its a great article. Making clear that how air pollutants are affecting the climate positively and negatively.

  4. Really this is a excellent article.Thanks a lot for sharing valuable information about climate change and its effect.I totally agree with your ideas.I think a polluted climate is the main cause of health diseases,global worming,green house effect etc.So in my opinion as much as possible we all should be aware of it.

  5. I remain unconvinced of the veracity of anthropogenic global warming, however, even if I accept the hypothesis how are we going to provide the vast energy requirements of the growing eastern economies of the next 50 – 100 years and at the same time reduce emissions of “greenhouse gases”? Patently we are not, we have to go down the nuclear route, no other power source will provide for our needs, if we do not I can see a major power shortage in the coming years.

    Ken Chadwick

Comments are closed.