Гвоздева Пхысицс фор адванцед студентс 2011

INTERVIEW WITH AN AMERICAN ENVIRONMENTAL

THINKER

Read the interview in pairs twice changing parts and answer the questions.

1.What kind of a phenomenon is “the greenhouse effect”?

2.How does it work?

3.What gases are responsible for “the greenhouse effect”?

4.What human activities principally cause enhanced greenhouse ef-

fect?

−Is it the greenhouse effect that is responsible for global warm-

ing?

−People misuse the term “greenhouse effect.” I guess it may be more accurate to talk about the enhanced greenhouse effect when considering the causes of global warming and climate change. The greenhouse effect is actually a very beneficial, naturally occurring phenomenon - without it, average surface temperature on the Earth would be about minus eighteen degrees centigrade which is the same as on the moon.

−What is the way it works?

−Radiation or heat from the sun hits the Earth and is radiated back at a different wavelength. At this wavelength, the radiation is trapped in the Earth’s lower atmosphere by greenhouse gases which include carbon dioxide and methane. These gases, in turn, radiate heat which warms the atmosphere. For millions of years, by insulating the Earth in this way, the greenhouse effect has created conditions suitable for civilization to develop.

−What is the problem now?

−Human activity over the last two hundred years has raised levels of greenhouse gases leading to more radiation absorption and re-radiation. It’s as if the Earth is now covered with a thick blanket which is causing it to overheat. We really shouldn’t underestimate the threat this poses. Carbon dioxide levels have increased 31% since 1750. Methane is the second biggest contributor to the greenhouse effect. Its share of the effect is about a fifth.

−What human activities cause enhanced greenhouse effect?

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− Agriculture and energy production accounts for about 60% of methane emissions. Methane’s GWP or global warming potential is twenty one. GWP takes into account factors such as potency as well as lifetime in the atmosphere.

INTERVIEW WITH CHARLES HILL

“Mankind is going to need a vast amount of energy in the future”

Dr Charles Hill, nuclear physicist and former lab director at Argonne National Laboratory

Read the interview in pairs twice, changing parts.

− What is, in your opinion, the most efficient and less polluting source of energy, capable to supply the power demand of the future?

− There is only one. It’s coal. It’s natural gas. Some limited additional use of the more exotic forms of energy, like solar and wind. But they are limited in what they can do. So it is going to be fossil fuel. The question immediately arises, well, how long will it last? And everyone has a different opinion on that. One thing that is certain is that the increase in the use of fossil fuels will sharply increase the amount of carbon dioxide in the atmosphere. Another thing is certain. You will put a lot more pollutants into the atmosphere in addition to carbon dioxide. One can point to natural gas. Well, natural gas has fewer pollutants, and it gives some considerable factor of perhaps two − more energy for the amount of carbon dioxide put into the air than does coal. But if you are increasing the amount of fossil fuels by a large number, like five, then the use of natural gas is not a long − term solution. It simply somewhat reduces what may be a very serious problem.

−What do you think about solar energy?

−Solar? No.

−Wind?

−No, small amounts only. The simplest form of pencil calculation will tell you that. The only way you can produce the vast amount of energy to supply the demand of mankind is with sources of energy, where the energy is concentrated. With solar energy the main problem is gathering it. In a nuclear form of energy, it is there. It has been gathered.

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