Three recent studies raise brand-new environmental dilemmas.
Is meat less of a climate-change culprit than we thought?
One frequent tip is to cut back on your meat intake for the sake of the planet. But according to Frank Mitloehner, a researcher from the University of California-Davis, that advice is hogwash.
Mitloehner takes exception to the widely cited claim that livestock are responsible for 18 percent of the world's anthropogenic greenhouse gas emissions — more than the entire transportation sector. That assertion comes from a 2006 paper from the U.N.'s Food and Agricultural Organization and has been cited by everyone from Paul McCartney to Rajendra Pachauri, the head of the Intergovernmental Panel on Climate Change, as a reason to reduce our consumption of animal products.
Mitloehner is skeptical about that 18 percent figure but doesn't claim that it's wrong, per se. It just doesn't apply to the United States: According to the EPA's inventory, transportation accounts for 26 percent of America's greenhouse gas emissions, whereas livestock's share is a measly 2.8 percent. Therefore, he concludes, Americans cutting back on meat and dairy would bring relatively small benefits.
But curbing our meat intake — particularly red meat, which is so much more resource-intensive than nearly all other food products — still seems like sound environmental advice to me, even if American farm animals aren't quite the global warming bogeymen we previously imagined.
Are we outsourcing our greenhouse gas emissions?
When we talk about a nation's carbon footprint, we generally mean the emissions produced within its borders — that is, whatever gets pumped out from its power plants, factories and so forth. But because goods produced in one country may be used in another, tallying up direct emissions may not be the best way of assigning responsibility for climate change. So two researchers from the Carnegie Institution of Washington, Steven J. Davis and Ken Caldeira, decided to construct an alternate emissions inventory — one that reflected countries' consumption patterns as opposed to just their production practices.
In their study published in Proceedings of the National Academy of Sciences, Davis and Caldeira found that nearly one-quarter of the world's energy-related carbon dioxide emissions — or 6.2 billion metric tons — is actually "traded" between countries, largely in the form of products moving from the developing world to wealthier nations.
America is the world's leading net importer, bringing in nearly 700 million metric tons in 2004, or 10.8 percent of our overall consumption-related emissions. The average American "consumes" 22 metric tons of CO2 annually, of which 2.4 tons are actually emitted abroad.
Meanwhile, China is the world's leading net exporter: 22.5 percent of its production emissions were related to goods that wound up outside the Middle Kingdom. China and India may now be among the world's biggest CO2 emitters, but the people in those countries aren't entirely to blame. As the world continues its struggle to reach a global consensus on climate change, that's a point developed nations would do well to keep in mind.
Can personal choices really make a big difference?
The Natural Resources Defense Council thinks so. The environmental action group just released a report, in conjunction with the Garrison Institute's Climate, Mind and Behavior Project, that outlines 14 free or low-cost things individuals can do that would collectively eliminate a billion tons of carbon dioxide equivalent — or almost 15 percent of America's total emissions.
It's not a particularly surprising list to anyone who's even mildly committed to green living. The report recommends keeping your vehicle properly maintained, using your clothes dryer sparingly, and replacing incandescent bulbs with compact fluorescent ones. (If every household replaced six interior bulbs and one exterior bulb, NRDC calculates that the country would avoid 30 million metric tons of CO2-equivalent.)