Is Global WarmingGood for Farming?

You might think alittle global warming is good for farming. Longer,warmer growing seasons

and more carbondioxide(CO 2 ）一what plantwouldn't love that?The agricultural industry basically agrees on that. Butglobal warming's effects on agriculture would actually

be quite complicated一and mostly not for the better.

It's true that somecrops will prosper on a warmer planet,but the key word thereis"some."According to a government report,higher CO 2 levels andlonger growing seasons

will increase yieldsfor fruit growers in the Great Lakesregion.But many major American crops already use CO 2 so efficiently that moreof it probably won't make much

difference to them.

What will make adifference are all the other things we'll have more or as temperatures rise一namely droughts（干旱）,bugs and big storms. More droughts mean lower crop

yields. Melting snowin the Western US will increase wateravailability in spring but decrease it in summer,forcing farmers to changecropping practices.As insects that eat

crops adapt theirmigration patterns to our warmer climate,farmers will have to either use moreinsecticide or plant hardier crops.

Farmers on bothcoasts are already starting to reap some of what the nation's fossil-fueladdiction has sown.Crops in those regions require a certain number of colderdays

or"winterchill"before they break dormancy（冬眠）and begin flowering. Too few cold days breaks the plants' floweringschedule which in turn affects pollination（授粉）

and hurts yield.

So,given how much isat stake for them,how are farm states working to shape climate legislation?Inresponse to agricultural demands,the Waxman-Markey bill frees the

agriculturalindustry from CO 2 emission limits and gives up control over what activitiesguarantee carbon offset credit to the Agricultural Department.

Some farmers一and some farm state congressionalleaders一have argued that because plants convert CO 2into oxygen,agricultural lands store more CO 2 than they emit. This

is onlytheoretically true.What we can say with certainty is that,like most bigindustries,farming is fossil-fuel intensive一large quantities of CO 2 are emitted from farm

equipment such asirrigation pumps and tractors.

"hardiercrops"(Last line,Para. 3)are most probably crops that_______.

A.need less water insummer

B.are more resistantto bugs

C.are strong enoughto stand even big storms

D.keep growingregardless of global warming