針對氣候變遷在歐陸尺度下對生物的衝擊，歐洲科學團隊創立了全球首見的量化指標，結果顯示氣候變化對歐洲鳥類已造成顯見影響。
在資料分析的122種常見鳥種中，若持續依照模式預測反應氣候暖化，不受其他因素干擾之下，有7成5將在分佈範圍內減少。其餘2成5的種類則預期會增加。
研究首席作者是英國皇家鳥類保育協會（RSPB）的葛戈利博士（Richard Gregory），他說，「結果顯示受到負面衝擊的種類遠多於受益的種類，比例是3比1。雖然目前全球均溫實際只有些微升高，我們卻發現生物族群有這麼大的變化，讓人驚訝。」
多數科學家都同意，想要避免氣候變化的嚴重惡果，必須控制全球暖化，相對於人類工業化前的溫度，維持增溫在攝氏2度以內。
這項研究發表在PloS ONE公共科學圖書館線上期刊，葛戈利博士所領導的團隊發現，歐洲常見與廣佈鳥類過去的族群數目變化與未來氣候變遷相關的分佈範圍變化之間有顯著關聯。
研究團隊整合出一項指標，顯示氣候變化對歐洲生物的影響。這項新指標已經被歐盟執委會（European Commission）納入一系列重點指標當中，用以評估2010年前終止生物多樣性流失的目標進程。
這份報告與指標是由皇家鳥類保育協會、杜爾罕大學（Durham University）、劍橋大學、歐洲鳥類調查委員會、法國國家自然史博物館、捷克鳥類協會與荷蘭統計局的科學家共同撰寫。
葛戈利博士也向歐洲各地經驗豐富的業餘賞鳥人士致謝，他們參與了「泛歐洲常見鳥類監測計畫」，將觀察資料提供給研究團隊。這個監測計畫由國際鳥盟（BirdLife International）與歐洲鳥類調查委員會協力共同舉辦。
杜爾罕大學的威力斯博士（Stephen Willis）指出，「預測在氣候變化中會得利的鳥類，在80年代中期就開始增加，預測會受害的鳥類則在同時期開始減少。讓人擔心的是，族群減少的種類佔了我們所有調查種類的75%。」
預測會減少的歐洲鳥種中，最顯著的前3名依序是田鷸（common snipe）、草地鷚（meadow pipit）、花雀（brambling）。
研究顯示某些歐洲鳥種未來將會增加，最多的前3名依序為黑頭林鶯（Sardinian warbler）、亞高山林鶯（subalpine warbler）、黃喉蜂虎（European bee-eater）。
國際鳥盟全球研究與指標計畫的召集人布查博士（Stuart Butchart）表示，「這是第一個氣候變化衝擊生物多樣性的有力指標。鳥類是人類了解最多的生物之一，這項指標再次顯示我們可以應用鳥類所提供的資訊，監控人類在地球上日益加深的足跡。」
Climate change is having an observable impact on birds across Europe, according to a scientific team that has created the world's first indicator of the impacts of climate change on wildlife at a continental scale.
Of the 122 common species included in the analysis, 75 percent are predicted to experience declines across their ranges if they continue to respond to climatic warming in the way the models predict, and in the absence of other barriers. The remaining 25 percent of species are projected to increase.
"The results show the number of species being badly affected outnumbers the species that might benefit by three to one," said lead author Dr. Gregory from the Royal Society for the Protection of Birds. "Although we have only had a very small actual rise in global average temperature, it is staggering to realize how much change we are noticing in wildlife populations."
Limiting global warming to no more than 2°Celsius above the temperature in pre-industrial times is necessary to avert the worst consequences of climate change, many scientists agree.
In a study published in the journal "PloS ONE," Dr. Gregory and his team showed a strong link between the observed population change of common and widespread European bird species and the projected range change associated with climate change.
Dr. Gregory credited skilled amateur birdwatchers across Europe who provided observations to the team through their work with the Pan-European Common Bird Monitoring Scheme. This project is a result of the common effort and shared goals of BirdLife International and the European Bird Census Council.
The team compiled an indicator showing how climate change is affecting wildlife across Europe. The new indicator already has been included in a high profile set of indicators being used by the European Commission to assess progress towards the target of halting biodiversity loss by 2010.
The paper and the indicator were produced by scientists from the RSPB, Durham University, the University of Cambridge, the European Bird Census Council, the Muséum National d'Histoire Naturelle, the Czech Society for Ornithology, and Statistics Netherlands.
"Those birds we predict should fare well under climate change have been increasing since the mid-80s, and those we predict should do badly have declined over the same period," said Dr. Stephen Willis of Durham University. "The worry is that the declining group actually comprises 75 percent of the species we studied."
Of those species projected to decline across Europe, the top three worst performers, in order, are: common snipe, Gallinago gallinago; meadow pipit, Anthus pratensis; and brambling, Fringilla montifringilla.
The research shows that the populations of a number of species are projected to increase across Europe. The top three increasing species, in order, are Sardinian warbler, Sylvia melanocephala; subalpine warbler, Sylvia cantillans; and European bee-eater, Merops apiaster.
"This is the first robust indicator of climate change impacts on biodiversity," said Dr. Stuart Butchart, BirdLife International's global research and indicators coordinator. "It provides another example of how information from birds - the best known class of organisms - can be used to monitor our growing footprint on the planet."
