CRI听力:Calculating Carbon Footprints

With climate change topping political agendas worldwide, the Australian farming industry is taking into account what it can do to lower emissions.

Agriculture produces around 16 percent of Australia's total emissions, making farmers a key part of the climate change solution.

Now one farmer has done his own greenhouse audit to see how the industry can improve.

David Cattanach owns a farm in Riverina, New South Wales. He's doing everything he can to measure and reduce his farm's carbon footprint. But Cattanach says it's not all for the good of the land.

"I wasn't looking at it from an environmental point of view. To be honest, I was using it as another tool to flag areas where we could pick up on efficiency."

From livestock to transportation, farm machinery and fertilizer, all were thoroughly checked.

Cattanach says he was surprised to find that fertilizer contributes almost half the emissions produced on the farm, followed closely by diesel fuel at 38 percent and machinery at 7 percent.

"We were a bit concerned that we might have made a mistake with the audit. We expected to see diesel use fuel use to be the main contributor."

To reduce his footprint, Cattanach is changing the way he farms and changing the way he does business.

He now leaves corn stubble on top of the soil instead of burning it. This simple technique reduces surface evaporation and will enrich the quality of the soil in the long term.

Paying farmers to store more carbon in the ground is a solution currently under consideration in Australia. But Cattanach says it is simply not worth his time.

"For every ton of carbon I'll store, I'll tie up $190 (U.S.) worth of nitrogen phosphorous and sulfur. It doesn't look like a very good investment, does it, if you're only going to give me 8 or 10 dollars a ton to tie it up for 100 years."

Cattanach was the first Australian to do an emissions audit on a working property. But now the Australian research group CSIRO is using those results to embark on a broader scheme working with 17 working groups across the country.

Scientists are testing new farming techniques like storing carbon in soil and producing higher yields while using less water. John Kirkegaard an agricultural researcher.

"All of our farmer groups were asked to benchmark their water use efficiency currently, and over the five years of the project they'll be looking to see how their innovations are improving. We know really that in many parts of Australia we're only achieving 60-70 percent of the efficiency that is possible, so there's lots of room for improvement."

Lowering inputs, maintaining or increasing yields and lowering emissions are all factors working together. Kirkegaard says the scheme is creating a nationwide exchange of ideas.

"They share their challenges, they share their ideas, and I think, get a lot out of sharing those ideas to move their particular enterprise forward."

With a forecast for less rainfall in Australia in the future, the research findings will give farmers a head start on an ever-changing environment.

For CRI, I am Li Dong.