A．that CFC manufacture is completely forbiddenB．that th……
TEXT E
When scientists first
warned in the 1970s that CFCs could attack ozone, the U.S. responded by banning
their use in spray cans. But the rest of the world continued to use CFC -based
aerosol cans, and overall CFC production kept growing. The threat became far
clearer in 1985, when researchers reported a "hole" in the ozone layer over
Antarctic. Although the size of the bole varies with the seasons and weather
patterns, at times Antarctic ozone has been depleted by as much as 50% in some
spots. As a result of this disturbing de- velopment,24 nations, including the U.
S. and the Soviet Union, met in Montreal two summers ago and a- greed to cut
back on CFCs. The so - called Montreal Protocal is designed to achieve a 35% net
reduction in worldwide CFC production by 1999.
That’s not good
enough, however, the same stability that makes CFC so safe in industrial use
makes them extremely longlives, some of the CFCs released today will still be in
the atmosphere a century from now. Moreover, each atom of chlorine liberated
form a CFC can break up as many as 100,000 molecules of ozone.
For this reason, governments should ensure the careful handling and
recycling of the CFC now in use. When plastic-foam burger holders are broken,
the CFCs trapped inside escape. Discarded refrigerators re- lease CFCs as well,
and, a significant part of the U.S. contribution to CFC emissions comes from
draining automobile air conditioners. Such release of CFCs could be prevented if
consumers and businesses were offered cash incentives to return brokendown air
conditioners and refrigerators to auto and appliance dealers. Then the units
could be sent back to the manufacturers so that the CFCs could be
reused.
While recycling will help, the only sure way to save the
ozone is a complete ban on CFC manufacture, which should be phased out over the
next five years. Fortunately, as the Montreal Protocal demonstrates, banning
CFCs will be far simpler than reducing other dangerous gases. But a ban could
admittedly be economically disruptive to the entire world: the annual market for
CFCs is some $ 2.2 billion. The Soviet Union, which is a heavy user of CFCs,
will have a particularly tough time phasing out the chemicals. "I agree with the
ban in principle, "said Vladimir Sakharov, a member of the Soviet State
Committee for Enviromental Protection, "but in practice it will be extremely
difficult. Our economy is not flexible as others."
To make the
transition easier, chemical companies are working hard to find practical
substitutes for CF- Cs. The most promising approach so far is to use CFC family
members that are chemically altered to make them less dangerous to the
environment. The chlorine - free substitutes is the high cost of making them. It
may be that until better manufacturing techniques are developed, consumers will
have to pay more for affected products. The prospect is not a pleasant one, it
is a small price to pay for curbing tile green house effect and saving the life
-preserving ozone layer.
The best way to save ozone is ______.
A．that CFC manufacture is completely forbidden
B．that the production of CFC is reduced
C．to find substitutes for CFCs
D．to reduce the danger of CFCs
