Unit8FocusonGlobalWarming课文翻译综合教程二

Unit 8 Focus on Global Warming John Weier

Twenty-five years ago if you made a trip to the local library and perused the periodical section for articles on global warming, you'd probably have come up with only a few abstracts from hardcore science journals or maybe a blurb in some esoteric geopolitical magazine. As an Internet search on global warming now attests, the

2 subject has become as rooted in our public consciousness as Madonna or microwave

Perhaps all this attention is deserved. With the possible exception of another world war, giant asteroid, or an incurable plague, global warming may be the single largest threat to our For decades human factories and cars have spewed billions of tons of greenhouse gases into the atmosphere, and the climate has begun to show some signs of warming. Many see this as a harbinger of what is to If we don't curb our greenhouse gas emissions, then low-lying nations could be awash in seawater, rain and drought patterns across the world could change, hurricanes could become more frequent, and El Ninos could become more intense.

Our Warming Planet

What has worried many people now is that over the past 250 years humans have been artificially raising the concentration of greenhouse gases in the atmosphere. Our factories, power plants, and cars burn coal and gasoline and spit out a seemingly endless stream of carbon dioxide. We produce millions of pounds of methane by allowing our trash to decompose in landfills and by

breeding large herds of methane-belching cattle.

Nitrogen-based fertilizers, which we use on nearly all our crops, release unnatural amounts of nitrogen oxide into the atmosphere.

Once these carbon-based greenhouse gases get into the atmosphere, they stay there for decades or longer. According to the Intergovernmental Panel on Climate Change (IPCC) since

the industrial revolution, carbon dioxide levels have increased 31 percent and methane levels have increased 151 percent. Paleoclimate readings taken from fossil records show that these gases, two of the most abundant greenhouse gases, are at their highest levels in the past 420,000 years. Many scientists fear

that the increased concentrations of greenhouse gases have prevented additional thermal radiation from leaving the Earth. In essence, these gases are trapping excess heat in the Earth 's atmosphere in much the same way that a windshield traps solar energy that enters a

Much of the available climate data appear to back these Temperature data gathered from many different sources all across the globe show that the surface

temperature of the Earth, which includes the lower atmosphere and the surface of the ocean, has risen dramatically over several decades. Worldwide measurements of sea level show a rise of to meters over the last century. That 's an increase of roughly 1 °C every 4,000 years. Readi ngs gathered from glaciers reveal a steady recession of the world 's continental glaciers. Taken together, all of these data

suggest that over the last century the planet has experienced the largest increase in surface temperature in 1,000 years.

Not surprisingly, many scientists speculate that such changes in the climate will probably result in hotter days and fewer cool According to the IPCC, land surface areas will increase in temperature over the summer months much more than the ocean. The mid-latitude to

high-latitude regions in the Northern Hemisphere — areas such as the Continental United States, Canada, and Siberia — will likely warm the most. These regions could exceed mean global warming by as much as 40 percent.

As far as humanhealth is concerned, those hit hardest will probably be residents of poorer countries that do not have the funds to fend against changes in climate. 7 A slight increase in