But the climate disruption caused by El Nino stretches far beyond the shores of the Pacific Ocean.Ocean currents which pull the warm water towards South America create winds which blow across Central America and the Caribbean into the Atlantic.These break apart storm clouds heading towards southern Africa.The result is drought there.
Plenty is known about El Nino s destructive potential, but the phenomenon itself remains frustratingly mysterious.Despite years of research，climatologists are still unable to predict how destructive an El Nino will be when it arrives.However, progress is being made on forecasting when one will occur.
This is vital because, if enough warning is given, steps can be taken to limit the destruction and suffering that follows a bad El Nino.At the very least,farmers would know whether to plant dry-or wet-weather crops.
Of more concern is the possible relationship between El Nino and global warming.Climatologists believe that El Nino will become more frequent and more severe in a warmer world.There is no conclusive evidence to support this,but it may be significant that the two most destructive El Nino on record occurred in the last two decades, which are the warmest on record.
If it turns out that El Nino is affected by global warming, it portends badly for the future.It would mean that even a very small increase in the average global temperature could totally alter the world s weather patterns.
This would upset many ecosystems, and could result in widespread starvation，disease epidemics,and the extinction of certain key species.El Nino is widely seen as a curse.But,if it makes us more aware of global warming, we may one day remember it as a blessing.
Notes on Language and Culture
1.batter : to beat hard and repeatedly.
2.deluge: a great flood; a very heavy rain.
3.upheaval: (a) great change and movement.
4.circumference: the length round the outside of a circle; distance round a round object；the line round the outside edge of a figure, object, or place;periphery.
5.nutrient : a substance providing for life and growth; food; nourishment.
6.deleterious: fml having an often unclear or unexpected harmful effect on the body, mind, or spirit.
7.plummet: to fall steeply and suddenly.
8.marine: of, near, living in, found in, or obtained from the sea.
9.arid: ( of land or a country) having so little rain as to be very dry and unproductive.
10.frustratingly: of having feelings of annoyed disappointment.
11.portend: fml to be a sign or warning of (a future undesirable event)
12.epidemic: a large number of cases of the same infectious disease during a single period of time.
13.extinction: the act of extinguishing or making extinct.
14.curse: a word or sentence asking God,heaven,a spirit,etc.to bring down evil or harm on someone or something.
C.Post-reading activity.
Think and answer the following questions:
1.What effects does El Nino have on the world s weather systems?2.What s the relationship between the oceans and the atmosphere?3.How do trade winds blow in a normal year?4.What happens in an El Nino year?5.Why does the author say that El Nino is also a blessing?Ⅳ.Fast Reading
In this part,you are required to read three passages and choose the best answers after each passage.
Where do pesticides fit into the picture of environmental disease ?We have seen that they now pollute soil, water, and food, that they have the power to make our streams fishless and our gardens and woodlands silent and birdless.
Man, however much he may like to pretend the contrary, is part of nature.Can he escape a pollution that is now so thoroughly distributed throughout our world?We know that even single exposures to these chemicals, if the amount is large enough, can cause extremely severe poisoning.But this is not the major problem.The sudden illness or death of farmers, farm workers, and others exposed to sufficient quantities of pesticides is very sad and should not occur.
For the population as a whole, we must be more concerned with the delayed effects of absorbing small amounts of the pesticides that invisibly pollute our world.
Responsible public health officials have pointed out that the biological effects of chemicals are cumulative over long periods of time, and that the danger to the individual may depend on the sum of the exposures received throughout his lifetime.For these very reasons the danger is easily ignored.It is human nature to shake off what may seem to us a threat of future disaster.
“Men are naturally most impressed by diseases which have obvious signs,”says a wise physician,Dr.Rene Dubos, “yet some of their worst enemies slowly approach them unnoticed.”
1.What is the author s attitude toward the environmental effects of pesticides?A.Concerned.B.Pessimistic.C.Indifferent.D.Defensive.
2.In the author s view, the sudden death caused by exposure to large amounts of pesticides.
A.now occurs most frequently among all accidental deaths.
B.has sharply increased so as to become the center of public attention.
C.is unavoidable because people can t do without pesticides in farming.
D.is not the worst of the negative consequences resulting from use of pesticides3.People tend to ignore the delayed effects of exposure to chemicals because.
A.the danger does not become apparent immediately.
B.limited exposure to them does little harm to people s health.
C.the present is more important for them than the future.
D.humans are capable of withstanding small amount of poisoning.
4.It can be concluded from Dr.Dubos remarks that.
A.people find invisible diseases difficult to deal with.
B.attacks by hidden enemies tend to be fatal.