clouds – not just for make believe

If someone mentions clouds to you, first thing that comes to your mind might be a fluffy, cartoony wisp in the sky, or childhood memories of gazing up into the mid-afternoon sky and imagining each cloud was some sort of object. Chances are that clouds being involved in climate change never really crossed your mind, but scientific studies show that they actually might be.

Elementary school science shows that certain colors reflect certain light. For example, red surfaces reflect red light and absorb every other color. The same goes for most other colors, but black and white are a bit different. The color black reflects no light, and the color white reflects all visible light. When visible light hits the ground or water, it reemits as infrared light. Well since clouds are white and reflect all visible light, they prevent a lot of heat being contributed to global warming.

So clouds reflect and block light; this means that in theory they would cool the earth. Whats the catch? Well the catch is that certain clouds reflect light and certain clouds actually trap heat. Clouds that are higher up tend to allow more light to hit the earth and also traps more heat than lower clouds. Heres a diagram that shows the effects of high and low clouds:

So in theory, since high clouds warm the earth, any anthropogenic warming that creates more high clouds will make global warming much worse. This is what we call a positive feedback loop. And the same works for low clouds. Since they have a cooling effect on the earth, then in theory, if anthropogenic warming created more low clouds then it would diminish the effects of global warming. We call this a negative feedback. Studies show some pretty concrete evidence regarding high and low clouds and how they affect climate, but there is still quite a bit of uncertainty about what kinds of clouds would be created as a result of anthropogenic warming. Climate scientist Chris Colose understands just this:

Unfortunately, the fact that clouds cool the planet on average tells us nothing about how cloud properties might change in a new climate. Suppose for example that the coverage of high clouds increased in a global warming scenario, while low clouds didn’t change at all. Because high clouds have a warming influence, one would expect this effect to amplify any warming that is caused by carbon dioxide or other human activities. This is an example of a positive feedback loop, but unfortunately we have very little understanding of cloud physics in a warming world. If the coverage of low clouds increased and reflected more sunlight, this would be a negative feedback, and would tend to mitigate the effects of human activities. Because of this uncertainty however, we can’t say with high confidence whether doubling the CO2 in our atmosphere will warm the planet by 3.5 degrees Fahrenheit or 8 degrees Fahrenheit…

This uncertainty creates 2 possibilites: Either anthropogenic warming creates a positive feedback loop with clouds and something should be done about it now or it creates a negative feedback where not so extreme measures must be taken. This uncertainty makes the job of a policymaker so much harder. I don’t really know the specifics, but one would expect that depending on the type of feedback created by the clouds, different actions must be taken.

What do you think should be done about it?

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7 responses to “clouds – not just for make believe”

  1. benb0017 says :

    I think that this was a well written post. I agree with you, in the fact that clouds can have a huge impact on global warming. I believe that I mentioned in your first post how some clouds can reflect heat that is still inside the earth and make it warmer, along with the higher clouds absorbing heat. The combination of these two clouds continue to warm the earth, and I believe something should be done about it and it should be done soon. Back on to the topic of your well written post, I think that you did an excellent job of giving the facts and letting us decide what should be done. I think that this is an admirable trait to have in your writing, as we hear enough opinions from everyone else. Anyways, great post, good topic, and great writing.

  2. annah0017 says :

    That was a really interesting post. Your point at the end about the two different possibilites and how “one would expect that depending on the type of feedback created by the clouds, different actions must be taken.” However, we don’t need to wait and see whether the climate change makes positive or negative feedback. We can’t wait. We’ve already waited long enough, don’t you think? So I feel like we should keep the clouds in mind, but try to fix the climate before we worry about the clouds above our heads.

    • omarim0017 says :

      Annah, you’re absolutely right, we really can’t wait much longer, time is running out. But the thing is, we really have to wait in order to do something. Clouds aren’t the only uncertainty that climate scientists have. As you may have already noticed, global warming is an enormous topic and it is on the borderline of impossible to understand everything there is to understand about global warming. In my opinion, it seems that the hardest part about deciding what to do about an issue is figuring out the things that you don’t know and if they’re important or not. For example, if I’m trying to cure a new disease, I have to figure out what the disease does, how its created and all that good stuff. In my eyes, the hardest part of the process would be trying to figure out the effects of the cure and how the interact with other factors, such as the patient and the disease itself. There are so many things to consider and with something as delicate as the earth’s ecosystem or a human being then its a risk you really can’t take. In my opinion, I think we should do a bit more research before acting.

  3. granta0017 says :

    Wow this is a really cool post, I had no idea this is what clouds did and I really enjoyed how you started of the post of how you look into the sky as a kid and think of fluffy puffballs or something along those lines and the picture at the end really helped me understand it more. Great post Omari!

  4. kmlewis1234567890 says :

    I liked the blog post and I really did learn a lot. But I have a question, do the clouds make a big enough difference on global warming to either be the cause global warming or stop it? And if it could really make a difference, is there a way to make more low lying clouds in order to reflect more sunlight cooling the earth? I am also wondering exactly why the high clouds trap heat and the low clouds reflect it. I suppose that could be because the high clouds are thinner but still, this is a very interesting topic to me.

    • omarim0017 says :

      Well kmlewis, to answer your first question, think of it this way: You’re playing outside on a hot, sunny day and nice large cloud passes over head, blocking the sun for about a minute. During that minute, you are able to feel a substantial difference in temperature, because the cloud is shading the ground below it. Now multiply that effect by the amount of clouds there are in the world and I think one could draw the conclusion that clouds may have a pretty large role in global warming. And I just gave you one way on how clouds affect the climate, so there are other factors that must be taken into account when it comes to how clouds specifically affect climate change. Now I’m not too sure if all of these factors are able to completely stop global warming all together but I think it might be something to look into.

      Now about your second question, I can honestly tell you that I’m not too sure. I’m not a cloud scientist but I do know that clouds are formed through a process called condensation, where water particles condense around other airborne particles in low temperatures to form clouds. What I don’t know is the different processes that create low clouds and that create higher clouds. So as of today’s technology, there might be some sort of machine that is able to produce some form of condensation in the air in a laboratory, but I’m not sure that it would be enough to create the enormous clouds that we see almost every day.

      Now for your third question, I’m going to use a section of Mr. Colose’s article to answer your question because I think he does a really good job doing so:

      “The reason high clouds are better at warming the planet is because they reside at altitudes much colder than the surface. When these high clouds absorb energy originating from the surface, they radiate “weaker” energy from a colder cloud top. From the perspective of someone looking down from space, the effect of this is to reduce the total amount of energy the planet sheds away, much like putting a blanket on. If the temperature of our atmosphere did not decrease with height in this fashion, then the influence of the greenhouse effect would disappear and the planet’s temperature would relax to some value determined by the energy absorbed from the sun. Similarly, if all the greenhouse gases like CO2 in our atmosphere could somehow be crunched into a thin layer near the surface, the terrestrial greenhouse effect would collapse and the planet would become much colder.”

    • clarkbeast says :

      Really interesting question, Miles. You might be interested to know that scientists are asking the same question: http://www.washington.edu/news/2012/08/20/experiment-would-test-cloud-geoengineering-as-way-to-slow-warming/

      This is one of a number of “geoengineering” proposals that some scientists are debating right now. We may have to try something like this? But for my part, I don’t think geoengineering should be seen as some sort of magic bullet or get-out-of-jail-free card. Implementing a plan like this without dealing with the underlying cause of greenhouse emissions seems like giving massive blood transfusions to a patient without also trying to stop the bleeding.

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