NASA Podcasts

Oceans of Climate Change
04.21.09
 
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Steve Biles: Climate change is something that affects all of our lives, whether we’re a student, a teacher or a scientist.
And speaking of scientists, I have a guest here with me today that can tell us a lot more about climate change, Josh Willis.
Now you’re an oceanographer here at JPL, correct?

Josh Willis: Well I’m an oceanographer but I study sea level rise, global warming and really how the ocean fits into that global warming picture.
Global warming is happening because people are emitting billions of tons of carbon dioxide and other green house gasses into the atmosphere. Now when they get there, these green house gasses cause extra heat to be trapped on the Earth so heat that would have otherwise been radiated back out into space is now sticking around and warming up our planet.

Steve: Now all that heat is trapped in our atmosphere but is it also affecting the oceans?

Josh: Turns out that 80 to 90 percent of the heat from global warming is actually going into the oceans so the oceans are really the big Earth heat bucket, that’s where all the heat winds up going.
It turns out the oceans can absorb 1000 times the amount of heat as the atmosphere without really changing their temperature all that much and the reason is because of something called heat capacity.

Steve: Do you have an example that could maybe explain heat capacity?

Josh: Let’s imagine that this balloon represents the whole Earth’s atmosphere so now my candle, my little lighter here, represents the sun, so let’s add some heat to it and see what happens.

Steve: Now don’t try this at home without adult supervision and proper safety equipment. Whoa. So, obviously the heat capacity of air is very low because it didn’t absorb any heat at all.

Josh: Well, that’s right, almost as soon as we put the candle to the balloon, it exploded, and the reason is because since the air inside the balloon couldn’t really absorb the heat that fast, all the heat went toward melting the rubber. As soon as the rubber melted, the balloon explodes.

Steve: Ah, okay cool. Now that’s a good demonstration of heat capacity of air, how about the heat capacity of water, or the oceans?

Josh: Yeah, let’s do the oceans. How about a water balloon Steve?

Steve: Sounds great.

Josh: All right, Steve, so this balloon filled with water represents the oceans and my lighter here represents the sun. Let’s put some heat on it and see what happens.

Steve: Wow, obviously it’s absorbing a great deal of heat.

Josh: Right, so you feeling the heat there Steve?

Steve: I am.

Josh: All right, but the balloon really isn’t because it turns out that the water can absorb so much heat that it takes the heat away from the skin of the balloon before the rubber can melt so the balloon doesn’t pop.

Steve: Excellent example, so the water has a tremendous ability to absorb heat and if that’s an analog for our oceans that means our oceans are absorbing a lot of heat as well.

Josh: That’s right, they sure are, Steve.

Steve: Well global warming sounds like quite a problem, what can we do about it?

Josh: Well the first thing we need to do Steve is really just understand the problem. Scientists all around the globe, including NASA scientists and here at JPL, we study data from satellites that measure the oceans and the atmosphere and these tell us about how global warming proceeds, and hopefully give us an idea of what the future’s going to look like.

Steve: It sounds like a pretty serious problem. What is it we can do?

Josh: Everything that we do almost uses some kind of energy and most of it is produced by burning fossil fuel, which release carbon dioxide into the atmosphere. We could turn off the lights when we leave the room, maybe power down that computer every once in a while and go outside, take a bike ride instead of getting in your car.

Steve: Well thanks Josh for coming in and talking to us today about climate change, we really appreciate your expertise. Josh: You bet Steve, my pleasure.

Steve: Okay, thanks much.

To learn more about climate change and how NASA and JPL are studying the problem, go to climate.jpl.nasa.gov.
And for more information about what NASA is doing in general, go to www.nasa.gov
NASA, Jet Propulsion Laboratory, California Institute of Technology

 

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