Food-waste reduction efforts should not distract public attention from the fact that buying less meat—particularly red meat—is even more effective for reducing both carbon emissions and pressure on our natural resources.
A broad range of efforts are needed to move toward sustainable food security for all, and each individual consumer contributes both to the problem and the solution.
「Waste not, want not, emit less」Science 352, 408–409 (22 Apr 2016) "Perspective"
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The long residence time of an anthropogenic CO2 perturbation in the atmosphere, combined with the inertia of the climate system, implies that past, current, and future emissions commit the planet to long-term, irreversible climate change. As a result, many key features of future climate change are relatively certain in the long term, even if the precise timing of their occurrence is uncertain.
人為的なCO2擾乱の長い滞留時間は、気候システムの慣性と相まって、過去・現在・未来の排出が長期にわたる不可逆的な気候変化につながることを暗示している。結果として、将来の気候変化の多くの特徴は長期的には比較的確かなものとなっている（それが起きる正確なタイミングは不確かだが）。
This long-term view shows that the next few decades offer a brief window of opportunity to minimize large-scale and potentially catastrophic climate change that will extend longer than the entire history of human civilization thus far. Policy decisions made during this window are likely to result in changes to Earth’s climate system measured in millennia rather than human lifespans, with associated socioeconomic and ecological impacts that will exacerbate the risks and damages to society and ecosystems that are projected for the twenty-first century and propagate into the future for many thousands of years.
今後数十年間が、これまでの人類の文明史全体よりも長く続く、大規模で破滅的な気候変化を軽減できるわずかな機会であることを本論文で示す。今後数十年間に下される政策決定が、今後数千年間の気候システムへの変化、今世紀や今後数千年間に及ぶ社会・生態系への影響を決定づける可能性が高い。
(…) even if carbon emissions are stabilized or reduced, atmospheric CO2 concentrations and surface temperatures would remain high and sea level would continue to increase for millennia.
（中略）もし炭素排出が安定化もしくは軽減されても、大気中のCO2濃度と地表温度は高いままであり、海水準は数千年間上昇し続ける。
Model projections based on the RCPs and each of the four emission scenarios shown in Fig. 1 indicate that twenty-first century global average warming will substantially exceed even the warmest Holocene conditions, producing a climate state not previously experienced by human civilizations.
各種排出シナリオに基づくモデル予測結果は、21世紀の全球的温暖化は完新世のもっとも暖かかった時期をはるかに凌ぐことを示しており、人類文明が経験したことのない気候状態を生み出すことを予想している。「Consequences of twenty-first-century policy for multi-millennial climate and sea-level change」Clark et al., 2016, Nature Climate Change "Perspective"
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It is natural to view the changes at this northernmost point in Antarctica as part of the inexorable southward march of anthropogenic climate change.
the oft-heard claim that the peninsula is the fastest-warming place on Earth is accurate only during the winter, as recorded at the Faraday/Vernadsky station on the west coast.
Although recent changes in the peninsula’s climate have been large, the natural decadal-scale variability is also large, making short-term fluctuations inherently unpredictable even in the presence of strong forcing.
This, combined with the large magnitude of natural variability, suggests that anthropogenic climate change may not be unambiguously detectable in Antarctica for several more decades.
Looking at surface-air temperatures13 collected for more than 60 years, the long-term trend is one of warming.
「Cooling in the Antarctic」Nature 535, 358–359 (21 July 2016) "News & Views"
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(...) to complicate matters further, species’ climate sensitivity is not fixed. The phenological mismatches lead to selection on the timing of phenological events. And, because phenology is often heritable, this leads to genetic change in sensitivity.
（中略）さらに状況を複雑にすることに、生物種の気候への感度は定まっていない。生物季節学的な不一致は生物季節学のタイミングの淘汰につながる。さらに、生物季節学はしばしば遺伝するので、感度の遺伝的変化につながる可能性がある。
「Interactions of climate change and species」Nature 535, 236–237 (14 July 2016) "News & Views"
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If cheap oil becomes the new normal, there may be no price constraint to prevent burning of the remaining underground oil and gas resources. In such a world, carbon emissions could continue to grow, and temperatures may rise to significant levels if no action is taken.
もし安い石油が新たな基準になってしまえば、地下に残されている石油ガス資源を燃やすことを妨げる価格的な制限はなくなってしまうだろう。そのような世界では、行動が起こされない限り、炭素排出は増加し続け、地表気温はかなりのレベルまで増加するだろう。
They find that long-term oil prices have a significant impact on cumulative emissions: low oil prices hamper climate mitigation action whereas high oil prices boost it.
長期的な石油価格が積算排出量にかなりの影響を与えることが研究から明らかになった。すなわち、低価格の石油は気候変化緩和行動を妨げ、高価格の石油はそれを促進することになる。
「Cheap oil slows climate mitigation」Nature Climate Change 6, 660–661 (2016) "News & Views"
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Haumann and colleagues’ findings emphasize that Antarctic sea ice is not merely a passive indicator of climate change and variability, but also a driver of changes in the climate system. Through its potential influence on ocean stratification and CO2 uptake, sea ice might have a bigger role than previously thought.
Haumannほかの発見は、南極の海氷は単に気候変化・変動の受動的な指標であるのではなく、気候システムの変化の駆動要因でもあるということを強調している。海洋の成層化・二酸化炭素の吸収に対する影響を通じて、海氷は従来考えられていたよりも大きい役割を負っている可能性がある。
「Southern Ocean freshened by sea ice」Nature 537, 40–41 (01 September 2016) "News & Views"
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The question is not whether Arctic changes are affecting mid-latitudes but rather how and by how much. Framing studies in this way will avoid polarization and aid progress. It is encouraging to see recent collaborations between scientists from what might be considered opposing camps; this sort of productive interaction will move the science, and with it the public discourse, forward.
疑問は「北極の変化が中緯度に影響を与えているのかどうか」ということよりは、「それがどのように・どれほど影響しているか」である。最近、意見が対立する研究者間でコラボレーションが行なわれていることを見るのはとても喜ばしいことであり、こうした生産性の高い相互作用が科学を動かし、大衆との対話を前向きなものにすることにつながるだろう。
「Effects of a warming Arctic」Science 353, 989-990 (02 Sep 2016) "Perspective"
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Different phytoplankton groups have evolved various physiological strategies that allow them to thrive in marine environments ranging from freezing, nutrient-rich polar waters to warm, nutrient-poor subtropical ocean deserts.
Few long-term time series of pelagic phytoplankton community composition exist, because phytoplankton sampling is costly and laborious and many ocean regions are vast and remote. Laboratory studies often focus on monocultures of a few strains and thus cannot fully capture ecosystem responses, in which physiological changes at the individual level are inextricably linked to changes in the relative fitness of different taxa in a changing environment.
(...) but global warming and ocean acidification may well act in concert to restructure future Pacific phytoplankton communities.
しかし地球温暖化と海洋酸性化は呼応して、将来の太平洋の植物プランクトン群衆を再構成するだろう。
「Adrift in an ocean of change」Science 350, 1466-1468 (18 Dec 2015) "Perspective"
