时间:2018-12-16 作者:英语课 分类:VOA标准英语2012年(一月)


英语课

Study: Ocean Acidity 1 Exceeds Natural Norms


New research suggests an overload 2 of carbon dioxide in the oceans is posing a serious threat to marine 3 life, food security and tourism.

While most CO2 emissions 4 from automobiles 5, buildings and factories go into the atmosphere, one-third ends up in the oceans, changing ocean chemistry and making seawater more acid.

A study in Nature Climate Change tracks ocean acidity over 21,000 years of climate history. Tobias Friedrich, co-author and post-doctoral fellow at the University of Hawaii International Pacific Research Center says the record shows natural increases in CO2 concentrations in the atmosphere over time and differences from region to region.

“This, of course, also had an effect on acidity levels in the ocean, and then (we) compared this naturally occurring increase in atmospheric 6 carbon dioxide concentrations with man-man emissions over the last two-hundred years.”

The scientists used computer models with data from ice and ocean sediment 7 cores to simulate ocean conditions, back to the ice age and forward to the end of the 21st century.

When Earth started to warm 17,000 years ago, at the end of the last ice age, atmospheric CO2 began to rise. Over the next 6,000 years, it grew from 190 parts per million to 280 parts per million.

Marine systems had time to adjust.

Axel Timmerman is a professor of oceanography at the University of Hawaii International Pacific Research Center and co-author of the study. He says the past 200 years paint a much different picture.

“Starting with the pre-industrial revolution, anthropogenic emissions increased so much that the oceans suddenly started to take up huge amounts of carbon.”

CO2 concentration in the atmosphere now stands at 392 parts per million. Timmerman says the study, which also includes 30 years of observational data, finds dangerously high levels of ocean acidification in certain regions.

“Such as the coral triangle, the western tropic of the Pacific and the Caribbean exceed the naturally occurring levels by factors of up to thirty in a few spots.”

Timmerman says this is happening at an accelerated pace. “The rate of change is about two orders of magnitude faster than what occurred during the last glacial period about 20 to 15,000 years ago.”

While ocean acidification could have been detected much earlier, scientists only began to monitor it a few decades ago. As seawater becomes more acid, carbonate - the mineral many sehllfish and corals use to form their shells and skeletons - is reduced.

Coupled with pollution and warming temperatures, it is a serious threat to ocean life. Axel Timmerman says his study gives decision-makers another tool for assessing that threat and evaluating the steps they can take to mitigate 8 it.



1 acidity
n.酸度,酸性
  • This plant prefers alkaline soil,though it will readily tolerate some acidity.这种植物在酸性土壤中也能生存,但硷性土壤更加适宜。
  • Gastric acidity would not prevent the organism from passing into the gut.胃的酸度不能防止细菌进入肠道。
2 overload
vt.使超载;n.超载
  • Don't overload the boat or it will sink.别超载,否则船会沉。
  • Large meals overload the digestive system.吃得太饱会加重消化系统的负担。
3 marine
adj.海的;海生的;航海的;海事的;n.水兵
  • Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
  • When the war broke out,he volunteered for the Marine Corps.战争爆发时,他自愿参加了海军陆战队。
4 emissions
排放物( emission的名词复数 ); 散发物(尤指气体)
  • Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
  • Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。
5 automobiles
n.汽车( automobile的名词复数 )
  • When automobiles become popular,the use of the horse and buggy passed away. 汽车普及后,就不再使用马和马车了。 来自《简明英汉词典》
  • Automobiles speed in an endless stream along the boulevard. 宽阔的林荫道上,汽车川流不息。 来自《现代汉英综合大词典》
6 atmospheric
adj.大气的,空气的;大气层的;大气所引起的
  • Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
  • Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。
7 sediment
n.沉淀,沉渣,沉积(物)
  • The sediment settled and the water was clear.杂质沉淀后,水变清了。
  • Sediment begins to choke the channel's opening.沉积物开始淤塞河道口。
8 mitigate
vt.(使)减轻,(使)缓和
  • The government is trying to mitigate the effects of inflation.政府正试图缓和通货膨胀的影响。
  • Governments should endeavour to mitigate distress.政府应努力缓解贫困问题。
学英语单词
acetylphosphoric acid
approbated
arteriola efferens
assembler loader package
babusar pass
basivolsella
beef stroganoffs
biosphere reserve
black teals
blandished
board bridge
breanna
calcium pyrophosphate
chemical insecticide
clear panel key
colouring book
computer forensics
cool-summer damage due to impotency
Cuproartinite
customs compound
customs supervision
decaudates
direct current source
documents-against-payment bill
DTRTT
electric resistance wire
enthalpy-entropy chart
excess mean portfolio return
firmware support
food-purchasing
four-address code
friction pressure
ghiaour
greys
Hawkins Point
hedonic price method
high-tempreature strain gauge
hovde
hyperpipecolatemia
intraploidy
job-lot production
kellwood
Keota
Koh Sla, Stung
lightly deformed crystal
lindeberg's condition
liquefaction temperature
Lloyd's anchors and chains proved
Loxwood
lymphonoduli aggregati
Madipelesa
magnaliums
mark sth up
megawatt (mw)
micromechanically
momentum cutoff
muhs
myristicic acid
nonutilized
obituarial
OGRL
Omlet
on-line cipher
orbiculately
ortho-nitraniline
Os Draconis
philosoph
piratesses
possessive pronoun
pritchie
pseudoprognathism
pulpitless
Q clearance
R. M. S.
rauca
reattend
remote sensing for atmospheric pollution
residual current operated protective device
Rhododendron mainlingense
sassen
sea language
see ... do
self-redemptions
simple HISAM data base
Skave
steam water interface
steering gear tube cam
stratum compactum of integument
stress bolt
suicide bombing
synchronization
tatouay
Thai Ridgebacks
thorotrast
turite
type of machine
varnish-treated tape
vigna angulariss
wage tax
wheeler and dealer
worm-gears