MARY LOUISE KELLY, HOST:
Here in the United States, cars and industry are the biggest emitters of greenhouse gases. In Africa, it's different. There, it's agriculture and a lot of it is cows. NPR's Eyder Peralta visited a lab trying to understand cow emissions.
EYDER PERALTA, BYLINE: As soon as I get into the office of Dr. Klaus Butterbach-Bahl, I get straight to the point.
We're literally talking farting and burping.
KLAUS BUTTERBACH-BAHL: It is burping, not farting.
PERALTA: When cows and other ruminants eat, the food first goes into the rumen, which acts like a biodigester. It's where grass and other plants are broken down by bacteria before they go into the abomasum, which is like our stomach.
BUTTERBACH-BAHL: Which means all the gas is produced in the rumen, and that's burping. And, of course, a little bit of farting as well, but...
PERALTA: But most of it...
BUTTERBACH-BAHL: But really more than 90 percent, 95 percent, is really burping.
PERALTA: Through the years, what Dr. Butterbach-Bahl and other scientists at the International Livestock Research Institute in Nairobi have found is that the amount of methane being burped by Western cows is not the same as what's being burped in Africa. Early research suggests cows here on the continent produce fewer greenhouse gases, but they also produce less milk and meat. Understanding that balance and the why is one of the central works of this lab.
BUTTERBACH-BAHL: And if you are thinking about how to mitigate emissions from agricultural sources, you should know where to go.
DANIEL KORIR: Hello, welcome.
PERALTA: Daniel Korir, a Ph.D. student, shows me around the animal yard. Some nine cows are in metal pens chewing fresh grass, curious about my microphone. Right now, Korir is testing a common breed of cow here in Kenya, and he's feeding them three common types of grasses. From this pen, he walks me inside to a futuristic-looking room.
KORIR: So this is the setup I'm calling respiratory chambers. And in essence, it's an open circuit system with this box in between the circuit.
PERALTA: The cows are in these huge, airtight, metal boxes, and they look out from small windows. A computer is measuring their burps and, well, their farts, too. Korir wants to find out what grasses make them fatter and which may produce less greenhouse gases.
KORIR: We are characterizing, actually, the tropical feeds with tropical forages, and this information is missing at the moment.
PERALTA: Maybe at the end of this 30-week experiment they'll find that a particular type of grass begets fatter cows and fewer greenhouse gases. Eyder Peralta, NPR News, Nairobi. Transcript provided by NPR, Copyright NPR.