The trendspotting USA Today last week proffered an upbeat assessment of the rise of so-called "green chemistry" -- what the U.S. EPA calls "the use of chemistry for pollution prevention."
Regardless of whether you find that notion oxymoronic -- perhaps harking back to Dupont's iconic, ironic tagline, adopted in 1939, "Better Living Through Chemistry" -- you'd better get used to it. As USA Today put it, "Green chemistry has gone from blackboard conjecture to a multimillion-dollar business."
Indeed, green chemistry is on the march. U.S. EPA hosts a program on the topic, as does the American Chemical Society. There's an academic journal by that title, along with research centers at colleges ranging from University of Oregon to the University of York; the latter hosts a Green Chemistry Network within its Department of Chemistry.
How "green" is green chemistry? Like just about everything else, it's all relative. A perusal of past winners of the U.S. EPA Presidential Green Chemistry Challenge, which promotes "innovative developments in and uses of green chemistry," reveals initiatives that seem worthy -- an enzyme technology to improve paper recycling, for example, or a "green synthesis" for manufacturing the cancer drug Taxol, using plant cell fermentation and extraction.
But as I said, it's all relative. Like the notion of "pollution prevention" itself, green chemistry typically promotes "less bad" ways of doing the same things, rather than rethinking the solutions altogether -- for example, a less-polluting alternative to a synthetic organic pesticide, as opposed to organic farming, which may obviate the need for the pesticide altogether.
So, green chemistry is a start, but it's far from what's possible. Contrast green chemistry with, for example, the potential for biomimicry, which "studies nature's models and then imitates or takes inspiration," in the words of my friend and colleague Janine Benyus, who wrote the seminal book on the topic.
Rather than ask, "What's a less-polluting way to do it?" biomimicry asks, "How would nature do it?" -- a fundamentally different question that opens up a fundamentally different set of solutions. So, rather than find a less-polluting polymer to manufacture plastic, as green chemistry might, it asks, as Cornell University professor Geoffrey W. Coates has done, How can you manufacture polymers from carbon dioxide, much as a leaf does?
It turns out that carbon dioxide is an ideal synthetic feedstock since it is abundant, inexpensive, nontoxic, and nonflammable. As Coates explains on his Web page, "Although it is estimated that nature uses CO2 to make over 200 billion tons of glucose by photosynthesis each year, synthetic chemists have had embarrassing little success in developing efficient catalytic processes that exploit this attractive raw material." Coates is working to change that.
Making plastics from an abundant natural resource instead of from fossil fuels -- or from crops, like corn, which require fossil fuels to grow: Now that's "green chemistry."