6 April 2009
Big Pictures of Mount Redoubt Eruption
Posted by Ryan Anderson
The Big Picture, an awesome photo-blog that you should be reading, has a very cool set of photos of the Mount Redoubt eruptions in Alaska. I thought it was especially cool to see how the glacier on top of the mountain is collapsing as it melts from beneath.
Update: Just like last time the Big Picture posted volcano photos, global warming deniers are posting in the comments and claiming that volcanoes make much more CO2 than humans, and therefore global warming is not man-made. Luckily, another commenter (#37) posted a very well-researched response on the Big Picture site. The Hawaii Volcano Observatory has also addressed this question: “Which Produces More CO2, Volcanic or Human Activity?”
The answer: on average, volcanoes produce less than 1% as much CO2 as fossil fuels do.
has anyone ever wondered how much CO2 is in the atomosphere. it is less than .0002 percent. I would like to know how does so little CO2 create global warming. I would say with that little CO2 in the air column would be like saying all my windows in my home are broken except the one facing north. This window will keep all the heat in my home.
Even though CO2 is a trace gas in Earth’s atmosphere, it is also nearly opaque to infrared light. If you could somehow see infrared light, CO2 would look dark because it absorbs infrared so well. This means that energy that would normally escape to space gets absorbed instead and re-radiated back to the surface. Water vapor and methane are even stronger IR absorbers than CO2, so they are even more potent greenhouse gases.
Your window analogy doesn’t really work because if all but one of the windows are broken, then over most of your house there is nothing stopping the heat from escaping. But on Earth, the CO2 is pretty evenly distributed. So if you wanted to make a house analogy, you should be thinking about the insulation, not the windows. Imagine you have your furnace set to put out a certain amount of energy, rather than to maintain a certain temperature. That furnace represents the sun. Now, you start off with some insulation, representing the natural amount of CO2 and water vapor and other greenhouse gases. But imagine you then added more layers of insulation. You furnace just keeps pumping out the energy, but now that energy can’t escape as quickly, so the house heats up.