【正文】 TH E EARTH IS BECO MIN G WARMER BUT DO ES IT MATTER? Duri ng the 20th century the tem perature of the earth rose about one degree Fahrenhei t. That probabl y does not seem m uch to you or m e, but i t i s a rapi d i ncrease when pared to other natural changes. So how has this e about and does i t m atter? Earth Care?s Sophi e Arm strong expl ores these questi ons. There i s no doubt that the earth i s be i ng warm er (see Graph 1) and that is i t hum an acti vi ty that has caused thi s gl obal warmi ng rather than a random but natural phenom enon. Al l sci enti sts subscri be to the vi ew that the i ncrease i n the earth?s tem perature i s due to the burni ng of fosil fuel s li ke coal , natural gas and oil to produce energy. Som e byproducts of thi s proces are cal ed “greenhouse” gases, the m ost im portant one of whi ch i s carbon di oxi de. Dr Jani ce Foster expl ai ns: “There i s a natural phenom enon that sci enti sts cal the ?greenhouse effect?. Thi s i s when sm al l am ounts of gases in the atm osphere, li ke carbon dioxi de, m ethane and water vapor, trap heat from the sun and therefore warm the earth. Wi thout the ?greenhouse effect?, the earth woul d be about thi rtythree degrees Cel sius cool er than i t i s. So, we need those gases. The probl em begi ns when we add huge quanti ti es of extra carbon di oxi de i nto the atm osphere. It m eans that m ore heat energy tends to be trapped i n the atmosphere causi ng the gl obal tem perature to go up. ” We know that the l evel s of carbon di oxi de have i ncreased greatly over the l ast 100 to 150 years. It was a sci enti st cal l ed Charl es Keeli ng, who m ade accurate measurem ents of the am ount of carbon di oxi de i n the atm osphere from 1957 to 1997. H e found that between these years the carbon di oxi de in the atm osphere went up from around 315 parts to around 370 parts per m il i on (see Graph 2). Al l sci enti sts accept thi s data. They al so agree that it i s the burning of m ore and m ore fossil fuels that has resulted i n thi s increase in carbon di oxi de. So how hi gh wi l the tem perature increase go? Dr Jani ce Foster says that over the next 100 years the am ount of warmi ng coul d be as l ow as 1 to 1. 5 degrees Celsi us, but i t coul d be as hi gh as 5 degrees. H owever, the atti tudes of sci entists towards thi s ri se are pl etel y di fferent. O n the one hand, Dr Foster thi nks that the t rend whi ch i ncreases the tem perature by 5 degrees woul d be a catastrophe. She says, “We can?t predict the cl im ate wel l enough to know what to expect, but it coul d be very seri ous.” O thers who agree with her thi nk there may be a ri se of several m etres in the sea l evel, or predi ct severe storm s, fl oods, droughts, fami nes, the spread of diseases and the di sapearance of speci es. O n the other hand, there are those, li ke Gee H am bl ey, who are opposed to thi s vi ew and bel i eve that we shoul d not worry about hi gh l evel s of carbon di oxi de i n the ai r. They predi ct that any warm i ng will be mi l d with few bad environm ental consequences. In fact, H am bl ey states, ” More carbon di oxi de i s actual l y a positi ve thi ng. It wil l m ake pl ants grow qui cker。 crops wil l produce m ore。 i t wi l encourage a greater range of anim als – al l of whi ch wi l m ake l i fe for hum an bei ngs beter.” Grenhouse gases conti nue to buil d up i n the atmosphere. Even i f we start reducing the am ount of carbon di oxi de and other greenhouse gases, the cl im ate i s goi ng to keep on warmi ng for decades or centuri es. N o one knows the efects of gl obal warmi ng. Does that m ean we shoul d do nothi ng? O r, are the ri sks too great? WHAT CAN WE DO ABOUT GLOBAL WARMING? Dear Earth Care, I am doi ng a project on behal f of m y school about gl obal warm i ng. Som eti m es I feel that i ndi vi dual s can have l i ttl e effect on such huge envi ronm ental probl em s. H owever, I sti l l thi nk peopl e shoul d advocate i m provem ents i n the way we use energy today. As I?m not sure where to start wi th m y project, I woul d appreci ate any suggesti ons you m ay have. Thank you O uyang Guang Dear O uyang Guang, There are m any peopl e heart and l ungs or that i t was m ore di ffi cul t for sm oki ng coupl es to bee pregnant. I certai nl y di dn?t know their babi es m ay have a sm al er bi rth wei ght or even be abnormal i n som e way. N ei ther di d I know that my ci garette sm oke coul d affect the heal th of knownsm okers. H owever, what I di d know was that m y gi rl fri end thought I sm el t terri bl e. She sai d m y breath and cl othes sm elt, and that the ends of m y fingers were turni ng yel ow. She tol d m e that she woul dn?t go out with m e again unl ess I stopped! I al so noti ced that I becam e breathl es qui ckl y, and that I wasn?t enjoyi ng sport as m uch. When I was taken off the school footbal team because I was unfi t, I knew i t was tim e to qui t smoki ng. I am sendi ng you som e advi ce I found on the Inter. It m i ght hel p you to stop and strengthen your resolve. I do hope so because I want you to l ive as l ong and heal thy a li fe as I have. Love from Grandad H ow can you stop sm oki ng? It i s not easy to stop sm oki ng, but mi l ions have m anaged to qui t and so can you. H ere are a few suggesti ons. Prepare yoursel f. Deci de on a day to quit. Don?t choose a day that you know i s goi ng to be stressful, such as the day of an exam . Make a li st of al the benefits you wi l get from stoppi ng sm oki ng. Then throw away your l ast packet of ci garettes. Be determi ned. Every tim e you feel li ke sm oki ng a cigarette, rem i nd yoursel f that you are a nonsm oker. Reread the li st of benefi ts you wrote earl i er. Break the habi t. Instead of sm oki ng a ci garette, do som ethi ng el se. Go for a wal k, cl ean your teeth, dri nk som e water, cl ean the house。 i n fa