OFF TOPIC: ILMASTO LÄMPENEE

[Bb]

Lähettäjä: Soijuv Lähetetty: 28.9.2006 11:56

Tutkijoiden mukaan maapallon lämpötila on nykyään lämpimämpi kuin mitä se on ollut koskaan 5000 vuoteen. Mikäli se nousee vielä asteen verran, nousee merenpinta vaarallisen korkealle, useita eliölajeja kuolee jne.


Earth hottest in 5,000 years, study suggests

http://www.world-science.net/othernews/ ... arming.htm

Sept. 25, 2006
Courtesy NASA
and World Science staff

Tem­pe­r­a­tures on Earth are hot­ter than they have been in sev­er­al thou­sand years, ac­cord­ing to a re­port in Mon­day?s ear­ly on­line is­sue of the re­search journal Proceedings of the National Academy of Sciences.

A further in­c­rease of 1° Cel­si­us (1.8° Fah­ren­heit) will pro­duce dan­ger­ous sea le­vel ri­ses and spe­cies ex­ter­mi­na­tions, the au­thors wrote.

The stu­dy, led by James Han­sen of NASA?s God­dard In­sti­tute for Space Stud­ies in New York, found that warm­ing over the past three dec­ades has pushed Earth past the hot­test lev­els in the cur­rent in­ter­gla­cial pe­ri­od, or time between ice ages. The cur­rent pe­r­i­od has last­ed near­ly 12,000 years. The pre­vi­ous rec­ord tem­pe­r­a­tures dur­ing this pe­ri­od are es­ti­mat­ed to have oc­curred around five or six mil­len­ni­a ago.

Re­cent warm­ing is forc­ing spe­cies of plants and an­i­mals to move to­ward the north and south poles, the re­port said.

The study used tem­pe­r­a­tures around the world tak­en dur­ing the last cen­tu­ry. Sci­en­tists con­clud­ed that these da­ta showed the Earth has been warm­ing at what they called a re­mark­ably quick rate of about 0.36° Fahr­en­heit (0.2° Cel­si­us) per dec­ade for the past 30 years.

?This ev­i­dence im­plies that we are get­ting close to dan­ger­ous lev­els of hu­man-made pol­lu­tion,? said Han­sen.

Hu­man-made ?green­house gas­es? are caus­ing glo­b­al warm­ing, ac­cord­ing to sci­en­tists. Green­house gas­es trap heat in the Earth?s at­mos­phere and warm the sur­face. Some green­house gas­es, which in­clude wa­ter va­por, car­bon di­ox­ide, meth­ane, ni­trous ox­ide, and ozone, oc­cur nat­u­ral­ly, while oth­ers are due to hu­man ac­tiv­i­ties.

Fur­ther glob­al warm­ing ?of more than 1°C, rel­a­tive to 2000, will con­sti­tute ?dan­ger­ous? cli­mate change as judged from like­ly ef­fects on sea lev­el and ex­ter­mi­na­tion of spe­cies,? the sci­en­tists wrote. The re­port ex­tends a re­cent find­ing that Earth is cur­rently hot­ter than at any time in the past 400 years.

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