首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
When Lewis Ziska wanted to see how a warmer wood with more carbon dioxide in the air would affect certain plants, he didn’t set
When Lewis Ziska wanted to see how a warmer wood with more carbon dioxide in the air would affect certain plants, he didn’t set
admin
2011-03-10
31
问题
When Lewis Ziska wanted to see how a warmer wood with more carbon dioxide in the air would affect certain plants, he didn’t set up his experiment in a greenhouse or boot up a computer model. He headed for Baltimore. Cities are typically 7 degrees warmer than the countryside, as well as big sources of CO2. So Ziska, a plant physiologist at the U.S. Department of Agriculture, compa,ed ragweed growing in vacant lots in Baltimore with ragweed in rural fields—and discovered the dark side of sunny claims that global warming will produce a "greening of planet Earth". Urban ragweed grows three to five times bigger than rural ragweed, starts spewing allergenic pollen weeks earlier each spring and produces 10 times more pollen. In as few as 20 years the whole world will have CO2 levels at least as high as some cities do now. As climate changes due to the greenhouse effect, hayfever sufferers would do well to lay in copious supplies of Kleenex.
From mosquitoes that carry tropical diseases such as malaria, to plants that produce allergenic pollen, scientists are finding that a warmer, CO2-rich world will be very, very. good for plants, insects and microbes that make us sick. Although the most obvious threat to human health is more frequent and more intense heat weaves, such as the one that killed thousands of people in Europe in 2003, that is only the beginning.
In the case of plants, it’s not just that they grow faster and shed pollen earlier as the woad warms. The carbon-enriched air also alters their physiology. In a six-year study at a pine forest managed by Duke University, where pipes and fans adjust the CO2 concentration and the air, scientists found that elevated CO2 increases the growth rate of poison ivy. More surprising, by increasing the air’s ration of carbon to nitrogen, elevated CO2 also increases the toxicity of urushiol, the rash-causing oil. "Poison ivy will become not just more abundant in the future," says Ziska. "It will also be more toxic. "
Plants interpret warmth and abundant CO2as: what a great climate for reproduction. Monitoring stations in Europe are recording higher pollen counts for allergenic grasses and trees, led by birch and hazel, notes a 2005 study by the Center for Health and the Global Environment at Harvard Medical School. Those counts are rising earlier each year: the warming already underway is shifting the pollen season by almost one day per year. By 2017, you’ll be reaching for tissues nine days sooner than you do now. More good news: in a greenhouse world po]len will be not only more abundant but more allergenic, he and Ziska find.
Since cities already have the high CO2 levels that the rest of the world can soon expect, "’there is no question these climate-related changes have already begun," says Arlington, Texas, Mayo," Dr. Robert Cluck. "Every summner we’re seeing West Nile virus earlier and earlier, and the higher levels of ozone that come with higher temperatures are increasing the rates of asthma and causing heart and lung damage comparable to living with a cigarette smoker. "
In a greenhouse world, tropical diseases will expand their range and their prevalence. For instance, alternating floods and droughts—the pattern that comes with climate change—provide perfect conditions for mosquitoes that carry malaria, West Nile and dengue fever. Warming makes mosquitoes bit more. They’ll face fewer predators, too. The frequent droughts expected in a greenhouse world are murder on damselflies and dragonflies.
As dengue fever, yellow fever and malaria extend their range to higher elevations and higher latitudes, those diseases could appear in the developed woad, too. The southern tier of western and eastern Europe, as well as the southern United States, are most at risk, says Harvard’s Epstein. Dengue fever has already popped up on the Mexican side of the U.S. border, a worrisome expansion of its current range. Say this for the climate contrarians who insist that a warmer world will he a better, more productive world: if they’re referring to allergens and pathogens, they’re dead right.
What is the author’s main purpose in writing this article?
选项
A、To introduce the recent research on global wanning done by physiologists.
B、To explain how plants, insects and microbes make humans sick.
C、To warn people of the serious impact that the global warming will have on human health.
D、To discuss the relation between climate change and life on earth.
答案
C
解析
主旨题。文中作者反复强调的是温室效应有利于有害的植物、昆虫和微生物的生长和疾病的传播,从而危害人类健康。故答案为[C]。
转载请注明原文地址:https://kaotiyun.com/show/tPYO777K
0
专业英语八级
相关试题推荐
Whimneighborhoodsarebecomingdarkerin【1】______andmoreexpensive.【1】______Analystssaythatsoaringhousepricesa
Whimneighborhoodsarebecomingdarkerin【1】______andmoreexpensive.【1】______Analystssaythatsoaringhousepricesa
Note-takingSkillsNote-takingrequiresahighlevelofabilityinmanyskills,particularlyinthefollowingfourmostimpo
Historicaldevelopmentsofthepasthalfcenturyandtheinventionofmoderntelecommunicationandtransportationtechnologiesh
Thespecializedortechnicallanguageofatrade,profession,orsimilargroupiscalled
"VisualMusic"isafine-tuned,highlydiverting,deceptivelyradicalexhibitionabouttherelationshipofmusicandmodernart,
A、beachB、highmountainsC、junglesD、waterfallsD
Fortunatelytherearestillafewtastythingsforusgourmandstoenjoyinrelativesecurity.Theirnumbers,however,aredeple
A、Thenumberoffamilymembers.B、Thesizeoftheirfuturehouse.C、Thetotalheightofallthefamilymembers.D、Theamountof
Whenimaginativementurntheireyestowardsspaceandwonderwhetherlifeexistsinanypartofit,theymaycheerthemselvesb
随机试题
国家对药品价格实行的是
营业税的纳税人是在我国境内有偿提供应税劳务、转让无形资产、销售不动产的单位和个人,包括()。
经营风险引起的是潜在损失,而交易风险和折算风险分别引起实际损失和账面损失。()
按照《保险法》的规定,下列说法中,不正确的是()。
利率是国家管理经济的重要工具,当经济衰退加剧、价格下降过快时,中央银行一般采取的调控方法是()。
甲股份有限公司为上市公司,2012年1月1日递延所得税资产为396万元,递延所得税负债为990万元,适用的所得税税率为25%。根据2012年颁布的新税法规定,自2013年1月1日起,该公司适用的所得税税率变更为15%。该公司2012年利润总额为6100万元
预防未成年人犯罪,在各级人民政府组织领导下,实行()。
在现实生活中,由于人们的立场和观点不同,对人活着的意义理解不同,存在着各种不同的人生观,人生观是:
西周法官在审判中判断当事人陈述真伪的方式叫做( )。
厂长:采用新的工艺流程可以大大减少炼铜车间所产生的二氧化碳。这一新流程的要点是用封闭式熔炉替代原来的开放式熔炉,同时,在固态下而不是在液态下按照流程把铜从一个熔炉转人下一个熔炉。但是,不仅购置和改造新的设备是笔大的开支,而且运作新流程的成本也高于目前的流程
最新回复
(
0
)