慢速美语 - 科学新闻 - World Food Production Also Having Big Effect on Climate

慢速美语 - 科学新闻 - World Food Production Also Having Big Effect on Climate Change

原文：

Most of the efforts aimed at reducing climate change center on reducing the use of fossil fuels. But a new study warns that pollution caused by the world’s food production system is also a major driver of rising temperatures on the planet.

The study found that if the world food system stays on its current growth path, it will produce nearly 1.4 trillion metric tons of greenhouse gases over the next 80 years.

That pollution is expected to come from fertilizers used in agriculture,mismanagedsoil, food waste and methane gas released from cows and other animals. Other causes include land-clearing operations and deforestation.

Researchers from the University of Minnesota and the University of Oxford in Britain led the study, which recentlyappearedin the publicationScience.

The researchers predict that even if fossil fuelemissionswere halted now, emissions from the world food system would make it impossible to reach current international climate change targets. They say that emissions from food production alone could push world temperatures past 1.5 degrees Celsius by the middle of this century and above 2 degrees Celsius by the end of the century.

A main goal of the 2015 United NationsParis Agreementon climate change is to keep rises in the Earth’s temperature during this century to between 1.5 to 2 degrees Celsius. The U.N. has said that in order to stay below the 1.5 Celsius level, emissions must fall at least 7.6 percent each year through 2030.

The new study calls for immediate “improvements in farming practices, as well as changes in what we eat and how much food we waste,” to help reach theParis Agreement goals.

Jason Hill is a professor of biosystems engineering at the University of Minnesota. He helped lead the study. He said in a statement that the research clearly demonstrates that food has a much greater effect on climate change than is widely known.

Hill also noted that fixing the problem would not require the world’s population to completely stop eating meat. “The whole world doesn’t have to give up meat for us to meet our climate goals,” he told the Associated Press. “We can eat better, healthier foods. We can improve how we grow foods. And we can waste less food.”

The researchers say such efforts areachievableand can also lead to many other improvements beyond controlling climate change. These include making humans healthier, reducing water pollution, improving air quality, preventing animalextinctionsand improving farm profitability.

The study makes the following predictions:

A nearly complete change to a plant-rich diet around the world could cut nearly 650 billion metric tons of greenhouse gases.

If almost everyone ate the right number ofcaloriesbased on age - around 2,100 calories a day for many adults - it would reduce emissions by about 410 billion metric tons.

If farming could reducecarbon levels- by using less fertilizer, managing soil better and doing better croprotation- it would cut greenhouse gases by nearly 540 billion metric tons.

And if people wasted less food - at home, in restaurants or by getting it to people in poorer countries – emissions could be cut by about 360 billion metric tons.

I’m Bryan Lynn.

Words in This Story

fossil fuel– n.a fuel, such as coal, oil, or natural gas, that is formed in the earth from dead plants or animals

greenhouse gas– n.relating to or caused by the warming of the Earth's atmosphere that is caused by air pollution

mismanage– v.to control or organize something badly

emission– n.the act of sending gas, heat or light out into the air

achievable–adj.able to be brought about or reached successfully

extinction– n.when a plant or animal completely dies out and disappears

calorie– n.a unit for measuring the amount of energy food provides

rotation– n.to regularly change the way a process is carried out