考研英语阅读篇章: 吃肉会引起气候变化
阅读基础如滴水穿石，连载考研英语阅读篇章，希望大家能保持阅读好习惯。考研英语阅读篇章：吃肉会引起气候变化
Eating meat contributes to climate change, due to greenhouse gasses emitted
by livestock. New research finds that livestock emissions are on the rise and
that beef cattle are responsible for far more greenhouse gas emissions than
other types of animals. It is published by Climactic Change. Carbon dioxide is
the most-prevalent gas when it comes to climate change. It is released by
vehicles, industry, and forest removal and comprises the greatest portion of
greenhouse gas totals. But methane(甲烷) and nitrous oxide are also greenhouse
gasses and account for approximately 28 percent of global warming activity.
Methane and nitrous oxide are released, in part, by livestock. Animals
release methane as a result of microorganisms that are involved in their
digestive processes and nitrous oxide from decomposing manure. These two gasses
are responsible for a quarter of these non-carbon dioxide gas emissions and 9
percent of total greenhouse gas emissions overall.
The research team, including Dario Caro, formerly of Carnegie and now at
the University of Siena in Italy, and Carnegie's Ken Caldeira, estimated the
greenhouse gas emissions related to livestock in 237 countries over a nearly
half a century and found that livestock emissions increased by 51 percent over
this period.
They found a stark difference between livestock-related emissions in the
developing world, which accounts for most of this increase, and that released by
developed countries. This is expected to increase further going forward, as
demand for meat, dairy products, and eggs is predicted by some scientists to
double by 2050. By contrast, developed countries reached maximum livestock
emissions in the 1970s and have been in decline since that time.
"The developing world is getting better at reducing greenhouse emissions
caused by each animal, but this improvement is not keeping up with the
increasing demand for meat," said Caro. "As a result, greenhouse gas emissions
from livestock keep going up and up in much of the developing world."
Breaking it down by animal, beef and dairy cattle comprised 74 percent of
livestock-related greenhouse gas emissions, 54 percent coming from beef cattle
and 17 percent from dairy cattle. Part of this is due to the abundance of cows,
but it is also because cattle emit greater quantities of methane and nitrous
oxide than other animals. Sheep comprised 9 percent, buffalo 7 percent, pigs 5
percent, and goats 4 percent.
"That tasty hamburger is the real culprit," Caldeira said. "It might be
better for the environment if we all became vegetarians, but a lot of
improvement could come from eating pork or chicken instead of beef."
页:
[1]