The insides of clouds may be the key to climate change

Feb 17, 2007

As climate change scientists develop ever more sophisticated climate models to project an expected path of temperature change, it is becoming increasingly important to include the effects of aerosols on clouds, according to Joyce E. Penner, a leading atmospheric scientist at the University of Michigan.

That's because aerosols, fine particles such as smoke and dust that form droplets in clouds and change cloud thickness, affect how much sun is able to pass through the cloud to Earth, as well as the amount of moisture that's returned to Earth. Both moisture and sunlight play significant roles in climate change.

"Think of it as having two clouds--one made of cotton and the other of Styrofoam," Penner said. "More sunlight and moisture will pass through a cloud of cotton as opposed to the denser cloud of Styrofoam. This difference is becoming more critical in terms of modeling future changes in the climate as we continue to produce more and more aerosols that form thicker and thicker clouds." Penner will present a talk on this topic, "Aerosol-Cloud Interactions and Climate Projections" during panel at a meeting of the American Association for the Advancement of Science in San Francisco on Feb. 17.

By comparing the observed temperature change record since 1850 with two different climate models, one that has low climate sensitivity and small amounts of aerosols and one that has high climate sensitivity and high amounts of aerosols, Penner's group showed that both models follow almost identical predictive paths in the past, but diverge significantly when predicting the temperature in the future

Penner's presentation also looks at the predictive capability of three climate models, a US NCAR-Oslo model, a French model and a Japanese model, and shows that differences are large, especially when the models predict both aerosols and their cloud effects in the assumed level of aerosols at the time, significantly changes the results. The differences are large partly because these models do not have high enough resolution to reproduce observations.

"We know that aerosol effects on clouds need to be included in climate models," Penner said, "but we need more research to reach optimum predictive properties for climate models."

Source: University of Michigan

Explore further: Indonesia volcano erupts, injuring 4; 1 missing

add to favorites email to friend print save as pdf

Related Stories

Fingers pointed as climate talks deadlock

42 minutes ago

Accusations flew at deadlocked UN climate talks in Lima on Saturday, as the United States warned that failure to compromise could doom the 22-year-old global forum.

Fun cryptography app pleases students and teachers

10 hours ago

Up on Google Play this week is Cryptoy...something that you might want to check out if you or someone you know wishes entry into the world of cryptography via an educational and fun app. You learn more about ciphers and keys; you ...

Recommended for you

Scientists make strides in tsunami warning since 2004

14 hours ago

The 2004 tsunami led to greater global cooperation and improved techniques for detecting waves that could reach faraway shores, even though scientists still cannot predict when an earthquake will strike.

Trade winds ventilate the tropical oceans

15 hours ago

Long-term observations indicate that the oxygen minimum zones in the tropical oceans have expanded in recent decades. The reason is still unknown. Now scientists at the GEOMAR Helmholtz Centre for Ocean Research ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.