Skip Navigation


Chemists Save the World!

April 8, 2009 at 2:50 pm
By Margaret Taylor '10

Or at least Nate Lewis, George L. Argyros Professor of Chemistry from Caltech, believes that they are going to.  Dr. Lewis has a rather remarkable résumé, including being listed as the 17th most influential person of the year by Rolling Stone Magazine.  His website says that “His research interests include artificial photosynthesis and electronic noses.”  Though electronic noses must be utterly fascinating, the reason for the talk he gave last Thursday was something far more serious: global warming.

Carleton College is a place with a particularly high incidence of people who’ve seen An Inconvenient Truth.  Dr. Lewis’s talk is like the advanced-class version of Al Gore’s famous PowerPoint.  He started off by disabusing us of some misconceptions we have about global warming and energy.  For example, the big problem society has is not that we’re going to run out of oil.  We already know about enough oil to last us for another 40 years, and based on what the US Geological Survey estimates we’ll discover in the future, we’ve got enough to last for another 150 years.  Add in coal reserves (which can be converted to oil), and there are enough fossil fuels to last for more than 2000 years.  The problem is the carbon dioxide that would be released if we burned all of that stuff.

For the rest of the presentation Dr. Lewis ran through the constraints of our future energy needs like an engineering problem.  Estimated population growth times estimated economic growth is roughly our estimated future energy demand.  He figures in the fact that industry gets gradually more energy-efficient as we develop better engineering, and that we have been gradually switching from high-carbon fuel sources, such as coal, to lower ones, like methane.  The discussion was peppered with witty asides and fun facts.  Did you know you use up about as much energy in food each hour as a 100-watt light bulb?

Dr. Lewis’s math leads to the inevitable conclusion that to meet the energy needs of the year 2050 without letting the carbon dioxide level in the atmosphere go above 550ppm, we’ll need to invent massive, massive amounts of energy sources that don’t release any carbon into the atmosphere at all.

Then he went over the possible means we have of obtaining all that zero-carbon energy.  Clean coal is not actually as oxymoronic as it sounds.  The process traps the carbon dioxide produced as the coal burns and buries it; the problem with this solution is that it might leak.  Nuclear power is risky, and geothermal, hydroelectric, tidal, biomass, and wind (sorry, twin windmills!) all can’t produce electricity on the enormous scale that we will need.  It’s no coincidence that Lewis’s lab at Caltech is doing research on the remaining possibility: solar.

Anybody who’s ever considered having a solar panel installed knows that current solar technology is very expensive.  Plus, it has a pesky habit of not working at night.  Dr. Lewis’s lab is working on developing new ways of converting light energy into electrical or chemical bond energy.  One of their projects is a kind of photosensitive particle that can be suspended in liquid and applied like paint.

The talk was sobering, but also quite educational.  Carleton Chem department, the future lies on your shoulders.