北冰洋冰层大面积融化 70%是人为造成
<p><span word="Study">Study</span> <span word="finds">finds</span> <span word="only">only</span> 30% <span word="of">of</span> <span word="radical">radical</span> <span word="loss">loss</span> <span word="of">of</span> <span word="summer">summer</span> <span word="sea">sea</span> <span word="ice">ice</span> <span word="is">is</span> <span word="due">due</span> <span word="to">to</span> <span word="natural">natural</span> <span word="variability">variability</span> <span word="in">in</span> <span word="Atlantic">Atlantic</span> – <span word="and">and</span> <span word="it">it</span> <span word="will">will</span> <span word="probably">probably</span> <span word="get">get</span> <span word="worse">worse</span>.</p><p><span word="The">The</span> <span word="radical">radical</span> <span word="decline">decline</span> <span word="in">in</span> <span word="sea">sea</span> <span word="ice">ice</span> <span word="around">around</span> <span word="the">the</span> <span word="Arctic">Arctic</span> <span word="is">is</span> <span word="at">at</span> <span word="least">least</span> 70% <span word="due">due</span> <span word="to">to</span> <span word="human">human</span>-<span word="induced">induced</span> <span word="climate">climate</span> <span word="change">change</span>, <span word="according">according</span> <span word="to">to</span> <span word="a">a</span> <span word="new">new</span> <span word="study">study</span>, <span word="and">and</span> <span word="may">may</span> <span word="even">even</span> <span word="be">be</span> <span word="up">up</span> <span word="to">to</span> 95% <span word="down">down</span> <span word="to">to</span> <span word="humans">humans</span> – <span word="rather">rather</span> <span word="higher">higher</span> <span word="than">than</span> <span word="scientists">scientists</span> <span word="had">had</span> <span word="previously">previously</span> <span word="thought">thought</span>.</p><p><span word="The">The</span> <span word="loss">loss</span> <span word="of">of</span> <span word="ice">ice</span> <span word="around">around</span> <span word="the">the</span> <span word="Arctic">Arctic</span> <span word="has">has</span> <span word="adverse">adverse</span> <span word="effects">effects</span> <span word="on">on</span> <span word="wildlife">wildlife</span> <span word="and">and</span> <span word="also">also</span> <span word="opens">opens</span> <span word="up">up</span> <span word="new">new</span> <span word="northern">northern</span> <span word="sea">sea</span> <span word="routes">routes</span> <span word="and">and</span> <span word="opportunities">opportunities</span> <span word="to">to</span> <span word="drill">drill</span> <span word="for">for</span> <span word="oil">oil</span> <span word="and">and</span> <span word="gas">gas</span> <span word="under">under</span> <span word="the">the</span> <span word="newly">newly</span> <span word="accessible">accessible</span> <span word="sea">sea</span> <span word="bed">bed</span>.</p><p><span word="The">The</span> <span word="reduction">reduction</span> <span word="has">has</span> <span word="been">been</span> <span word="accelerating">accelerating</span> <span word="since">since</span> <span word="the">the</span> 1990<span word="s">s</span> <span word="and">and</span> <span word="many">many</span> <span word="scientists">scientists</span> <span word="believe">believe</span> <span word="the">the</span> <span word="Arctic">Arctic</span> <span word="may">may</span> <span word="become">become</span> <span word="ice">ice</span>-<span word="free">free</span> <span word="in">in</span> <span word="the">the</span> <span word="summers">summers</span> <span word="later">later</span> <span word="this">this</span> <span word="century">century</span>, <span word="possibly">possibly</span> <span word="as">as</span> <span word="early">early</span> <span word="as">as</span> <span word="the">the</span> <span word="late">late</span> 2020<span word="s">s</span>.</p><p>"<span word="Since">Since</span> <span word="the">the</span> 1970<span word="s">s</span>, <span word="there">there</span>'<span word="s">s</span> <span word="been">been</span> <span word="a">a</span> 40% <span word="decrease">decrease</span> <span word="in">in</span> <span word="the">the</span> <span word="summer">summer</span> <span word="sea">sea</span> <span word="ice">ice</span> <span word="extent">extent</span>," <span word="said">said</span> <span word="Jonny">Jonny</span> <span word="Day">Day</span>, <span word="a">a</span> <span word="climate">climate</span> <span word="scientist">scientist</span> <span word="at">at</span> <span word="the">the</span> <span word="National">National</span> <span word="Centre">Centre</span> <span word="for">for</span> <span word="Atmospheric">Atmospheric</span> <span word="Science">Science</span> <span word="at">at</span> <span word="the">the</span> <span word="University">University</span> <span word="of">of</span> <span word="Reading">Reading</span>, <span word="who">who</span> <span word="led">led</span> <span word="the">the</span> <span word="latest">latest</span> <span word="study">study</span>.</p><p>"<span word="We">We</span> <span word="were">were</span> <span word="trying">trying</span> <span word="to">to</span> <span word="determine">determine</span> <span word="how">how</span> <span word="much">much</span> <span word="of">of</span> <span word="this">this</span> <span word="was">was</span> <span word="due">due</span> <span word="to">to</span> <span word="natural">natural</span> <span word="variability">variability</span> <span word="and">and</span> <span word="therefore">therefore</span> <span word="imply">imply</span> <span word="what">what</span> <span word="aspect">aspect</span> <span word="is">is</span> <span word="due">due</span> <span word="to">to</span> <span word="man">man</span>-<span word="made">made</span> <span word="climate">climate</span> <span word="change">change</span> <span word="as">as</span> <span word="well">well</span>."</p><p><span word="To">To</span> <span word="test">test</span> <span word="the">the</span> <span word="ideas">ideas</span>, <span word="Day">Day</span> <span word="carried">carried</span> <span word="out">out</span> <span word="several">several</span> <span word="computer">computer</span>-<span word="based">based</span> <span word="simulations">simulations</span> <span word="of">of</span> <span word="how">how</span> <span word="the">the</span> <span word="climate">climate</span> <span word="around">around</span> <span word="the">the</span> <span word="Arctic">Arctic</span> <span word="might">might</span> <span word="have">have</span> <span word="fluctuated">fluctuated</span> <span word="since">since</span> 1979 <span word="without">without</span> <span word="the">the</span> <span word="input">input</span> <span word="of">of</span> <span word="greenhouse">greenhouse</span> <span word="gases">gases</span> <span word="from">from</span> <span word="human">human</span> <span word="activity">activity</span>.</p><p><span word="He">He</span> <span word="found">found</span> <span word="that">that</span> <span word="a">a</span> <span word="climate">climate</span> <span word="system">system</span> <span word="called">called</span> <span word="the">the</span> <span word="Atlantic">Atlantic</span> <span word="multi">multi</span>-<span word="decadal">decadal</span> <span word="oscillation">oscillation</span> (<span word="AMO">AMO</span>) <span word="was">was</span> <span word="a">a</span> <span word="dominant">dominant</span> <span word="source">source</span> <span word="of">of</span> <span word="variability">variability</span> <span word="in">in</span> <span word="ice">ice</span> <span word="extent">extent</span>. <span word="The">The</span> <span word="AMO">AMO</span> <span word="is">is</span> <span word="a">a</span> <span word="cycle">cycle</span> <span word="of">of</span> <span word="warming">warming</span> <span word="and">and</span> <span word="cooling">cooling</span> <span word="in">in</span> <span word="the">the</span> <span word="North">North</span> <span word="Atlantic">Atlantic</span> <span word="that">that</span> <span word="repeats">repeats</span> <span word="every">every</span> 65 <span word="to">to</span> 80 <span word="years">years</span> – <span word="it">it</span> <span word="has">has</span> <span word="been">been</span> <span word="in">in</span> <span word="a">a</span> <span word="warming">warming</span> <span word="phase">phase</span> <span word="since">since</span> <span word="the">the</span> <span word="mid">mid</span>-1970<span word="s">s</span>.</p>
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