譯/莊蕙嘉
保存原始林 降低碳排量
Forests are a great bulwark against climate change, so programs to reduce deforestation are important. Those efforts usually focus on stopping the destruction in areas where it is already occurring.
森林是對抗氣候變遷的重要堡壘，因此減少森林濫伐計畫很重要。這些努力常聚焦於已遭濫伐區，讓破壞不再繼續。
But a new study suggests these programs would do well to also to preserve forests where deforestation and degradation have not begun. Gradual loss of these largely pristine, intact forests has a much greater climate effect than previously accounted for, the researchers said.
但新研究指出，這些計畫若同時著力於保護濫伐和劣化尚未開始的森林，成效會更好。研究員說，這些大抵原始且未受侵擾的森林逐漸流失，對氣候變遷影響遠比原本評估大。
Globally, forests take more than a quarter of the carbon emissions from human activities out of the atmosphere every year. Intact forests are especially effective at storing carbon — although only about 20% of tropical forests are considered relatively pristine, they are responsible for about 40% of carbon storage in the tropics.
就全球而言，森林每年自大氣吸收的碳，超過人類活動製造的總碳排放量的四分之一。完整的森林貯碳能力又特別強，雖然約僅20%熱帶森林被視為相對原始，它們的碳貯存量在熱帶森林碳貯存總量中的占比，卻約達40%。
The study, by researchers from the Wildlife Conservation Society, the University of Queensland in Australia and other institutions, analyzed carbon emissions from the loss of intact tropical forests worldwide from 2000 to 2013.
這項研究由國際野生生物保育學會、澳洲昆士蘭大學和一些機構合作進行，分析自2000年至2013年間，全球完整熱帶森林流失導致的碳排放量。
Immediate clearing of intact forests, what might be considered "classic" deforestation, over that period accounted for about 3% of global emissions from deforestation in all tropical forests, the researchers said. But when they looked at other, more gradual types of loss and disturbance — forests that had been opened to selective logging, for example, or road-building that exposed more trees — they found that the carbon effect increased sixfold over the period.
完整森林直接完全砍伐，可視為「典型的」去森林化。研究人員說，那段期間，全球熱帶森林砍伐所產生的碳排放，完全砍伐的占比約3%，但在檢視並計入其他更漸進式的森林消失和侵擾，例如森林開放供選擇性砍伐，或是因開闢道路而使更多樹木曝露後，他們發現碳排占比竟增高了六倍。
"It's alarming, because there are huge amounts of intact forest being disturbed every year," said Tom Evans, who leads the forest conservation program at the Wildlife Conservation Society and was a co-author of the paper, which was published in Science Advances.
湯姆．伊凡斯是國際野生生物保育學會的森林保育計畫負責人，也是刊載於「科學進展」期刊的前述報告的共同作者，他說：「這個結果令人不安，因為每年都有數量龐大的完整森林受到侵擾。」。
The study amounts to a more complete accounting of the carbon effect of forest loss. Some of the effect comes not from newly accounted for emissions but from what the researchers called "forgone removals" — a degraded or disturbed forest takes up less carbon from the atmosphere than a fully intact one.
關於森林流失對減碳的影響，這分研究作出了更加完整的說明。這個影響一部分並非來自新的排放，而是來自研究人員所稱的「喪失的吸存移除（碳）量」，意指比起完整無缺的森林，劣化或受侵擾的森林自大氣捕集的碳變少了。
"These forests are working for us each year, soaking up large amounts of carbon," Evans said. "But we don't account for that when the damage happens."
「這些森林每年為我們工作，吸收大量的碳。」伊凡斯說。「但是在森林受到損害時，我們卻沒有正視它的影響。」
For one thing, if preserving an intact forest has a climate impact six times greater than previously thought, perhaps the financial incentive to preserve it should be substantially higher, he said.
比方說吧，如果保護一座完整森林的氣候效果比過去以為的好上六倍，或許保存森林的財務獎勵應該大幅提高。
International programs like Reducing Emissions from Deforestation and Forest Degradation, or REDD+, are seen as a way to help limit global warming by using financial incentives to halt ongoing deforestation, thus conserving forests' carbon-storing capabilities.
諸如「減少森林濫伐及森林退化碳排放」（或稱作REDD+）這樣的國際計畫，被視為限制全球暖化的一種方式，做法是藉由提供財務獎勵遏止進行中的森林砍伐，從而守護森林貯碳的能力。
※說文解字看新聞
本文報導碳排放研究的新發現，完整的森林（intact forests）有更好的減碳效果。完整森林也就是保育界所謂「未受（人類） 侵擾的原始森林」，除吸存大量溫室氣體二氧化碳，抑制暖化外，更為陸生野生動物（terrestrial wildlife）提供棲息地（habitat)，十分重要。
deforestation是deforest的名詞，指林木被大面積砍伐，焚燒，導致森林消失的現象，有「濫伐」「毀林」、「去森林化」等多種譯法。
degradation/degrade指事物狀態變差，文中指森林劣化，包括樹木數量、樹種、棲息生物等逐漸減少的過程。
preserve和conserve都是談到環保時常見的字彙，都有protect something from loss or change的含意。preserve常譯為保存，主要指盡力維持其原有狀態，勿使損傷劣化。conserve多譯為保存，強調妥善管理或節省使用資源，讓耗損量低於替補量，除了保存，還要孕育，以求永續。
