2013年8月2日讯 /生物谷 Bioon/--2013年5月地球上的大气中的二氧化碳超过400 ppm，尽管强调这一数字，只是人类赋予它的象征意义而已，但是这无疑提醒我们需要重新审视一下当前的经济发展对CO2的贡献了。
7月29日，《科学公共图书馆》（PLoS）称，8月5日在美国明尼苏达召开的美国生态学大会（Ecological Society of America meeting）将主要对当前气候变化所造成的影响进行评估。一年一届的美国生态学大会是生态学者就美国乃至全球的生态问题进行广泛交流和讨论的一次盛会。
8月2日，Science出版有关于气候变化的专刊。气候变化已然成为事实，但一些媒体和公众仍在质疑气候变暖，因为最新研究的确发现近几年气候变暖的趋势在逐渐趋缓。如何从多如牛毛的报道和文献中找到自己的方向，应该相信谁，不应该相信谁。
显然让普通民众认识气候变化是一项艰巨的任务，正如Science主编Marcia McNutt说道：“对于我们来说，评估气候变化对预计未来的影响，是我们这个时代最重要的挑战之一。”，此专刊有助于我们对气候变化的认识。如下将本期Science专刊相关的文章罗列出来。（生物谷 Bioon.com）
生物谷推荐的英文摘要
Once and Future Climate Change
Caroline Ash, Elizabeth Culotta, Julia Fahrenkamp-Uppenbrink, David Malakoff, Jesse Smith, Andrew Sugden, Sacha Vignieri
Anthropogenic climate change is now a part of our reality. Even the most optimistic estimates of the effects of contemporary fossil fuel use suggest that mean global temperature will rise by a minimum of 2°C before the end of this century and that CO2 emissions will affect climate for tens of thousands of years. A key goal of current research is to predict how these changes will affect global ecosystems and the human population that depends on them. This special section of Science focuses on the current state of knowledge about the effects of climate change on natural systems, with particular emphasis on how knowledge of the past is helping us to understand potential biological impacts and improve predictive power.
Climate Change and Cumulative Impacts
M. McNutt
Anticipating the future under the influence of climate change is one of the most important challenges of our time, and the topic of the special section in this issue of Science (see p. 472). The natural systems that provide oxygen, clean water, food, storm and erosion protection, natural products, and the potential for future resources, such as new genetic stocks for cultivation, must be protected, not just because it is part of good stewardship but also so that they can take care of us. But even the first step of modeling the effects of greenhouse gas sources and sinks on future temperatures requires input from atmospheric scientists, oceanographers, ecologists, economists, policy analysts, and others. The problem is even more difficult because the very factors that influence temperature changes, such as ocean circulation and terrestrial ecosystem responses, will themselves be altered as the climate changes.With so many potential climate-sensitive factors to consider, scientists need ways to narrow down the range of possible environmental outcomes so that they know what specific problems to tackle.
How a Fickle Climate Made Us Human
Ann Gibbons
Many researchers agree that shifts in climate and environment shaped human evolution, but there has been little direct evidence about exactly how. Now researchers are drilling cores to gather geological data in the African landscapes where human ancestors once lived. Such localized data may help test ideas such as the savanna hypothesis, which proposes that the rise of grasses accompanied the birth of hominins.
Changes in Ecologically Critical Terrestrial Climate Conditions
Noah S. Diffenbaugh1,2,*, Christopher B. Field3
Terrestrial ecosystems have encountered substantial warming over the past century, with temperatures increasing about twice as rapidly over land as over the oceans. Here, we review the likelihood of continued changes in terrestrial climate, including analyses of the Coupled Model Intercomparison Project global climate model ensemble. Inertia toward continued emissions creates potential 21st-century global warming that is comparable in magnitude to that of the largest global changes in the past 65 million years but is orders of magnitude more rapid. The rate of warming implies a velocity of climate change and required range shifts of up to several kilometers per year, raising the prospect of daunting challenges for ecosystems, especially in the context of extensive land use and degradation, changes in frequency and severity of extreme events, and interactions with other stresses.
Marine Ecosystem Responses to Cenozoic Global Change
R. D. Norris1,*, S. Kirtland Turner1, P. M. Hull2, A. Ridgwell3
The future impacts of anthropogenic global change on marine ecosystems are highly uncertain, but insights can be gained from past intervals of high atmospheric carbon dioxide partial pressure. The long-term geological record reveals an early Cenozoic warm climate that supported smaller polar ecosystems, few coral-algal reefs, expanded shallow-water platforms, longer food chains with less energy for top predators, and a less oxygenated ocean than today. The closest analogs for our likely future are climate transients, 10,000 to 200,000 years in duration, that occurred during the long early Cenozoic interval of elevated warmth. Although the future ocean will begin to resemble the past greenhouse world, it will retain elements of the present “icehouse” world long into the future. Changing temperatures and ocean acidification, together with rising sea level and shifts in ocean productivity, will keep marine ecosystems in a state of continuous change for 100,000 years.
Climate Change and the Past, Present, and Future of Biotic Interactions
Jessica L. Blois1,*, Phoebe L. Zarnetske2, Matthew C. Fitzpatrick3, Seth Finnegan4
Biotic interactions drive key ecological and evolutionary processes and mediate ecosystem responses to climate change. The direction, frequency, and intensity of biotic interactions can in turn be altered by climate change. Understanding the complex interplay between climate and biotic interactions is thus essential for fully anticipating how ecosystems will respond to the fast rates of current warming, which are unprecedented since the end of the last glacial period. We highlight episodes of climate change that have disrupted ecosystems and trophic interactions over time scales ranging from years to millennia by changing species’ relative abundances and geographic ranges, causing extinctions, and creating transient and novel communities dominated by generalist species and interactions. These patterns emerge repeatedly across disparate temporal and spatial scales, suggesting the possibility of similar underlying processes. Based on these findings, we identify knowledge gaps and fruitful areas for research that will further our understanding of the effects of climate change on ecosystems.
The Future of Species Under Climate Change: Resilience or Decline?
Craig Moritz1,2,3,*, Rosa Agudo1
As climates change across already stressed ecosystems, there is no doubt that species will be affected, but to what extent and which will be most vulnerable remain uncertain. The fossil record suggests that most species persisted through past climate change, whereas forecasts of future impacts predict large-scale range reduction and extinction. Many species have altered range limits and phenotypes through 20th-century climate change, but responses are highly variable. The proximate causes of species decline relative to resilience remain largely obscure; however, recent examples of climate-associated species decline can help guide current management in parallel with ongoing research.
Climate Change Impacts on Global Food Security
Tim Wheeler1,2,*, Joachim von Braun3
Climate change could potentially interrupt progress toward a world without hunger. A robust and coherent global pattern is discernible of the impacts of climate change on crop productivity that could have consequences for food availability. The stability of whole food systems may be at risk under climate change because of short-term variability in supply. However, the potential impact is less clear at regional scales, but it is likely that climate variability and change will exacerbate food insecurity in areas currently vulnerable to hunger and undernutrition. Likewise, it can be anticipated that food access and utilization will be affected indirectly via collateral effects on household and individual incomes, and food utilization could be impaired by loss of access to drinking water and damage to health. The evidence supports the need for considerable investment in adaptation and mitigation actions toward a “climate-smart food system” that is more resilient to climate change influences on food security.
Climate Change and Infectious Diseases: From Evidence to a Predictive Framework
Sonia Altizer1,*, Richard S. Ostfeld2, Pieter T. J. Johnson3, Susan Kutz4, C. Drew Harvell5
Scientists have long predicted large-scale responses of infectious diseases to climate change, giving rise to a polarizing debate, especially concerning human pathogens for which socioeconomic drivers and control measures can limit the detection of climate-mediated changes. Climate change has already increased the occurrence of diseases in some natural and agricultural systems, but in many cases, outcomes depend on the form of climate change and details of the host-pathogen system. In this review, we highlight research progress and gaps that have emerged during the past decade and develop a predictive framework that integrates knowledge from ecophysiology and community ecology with modeling approaches. Future work must continue to anticipate and monitor pathogen biodiversity and disease trends in natural ecosystems and identify opportunities to mitigate the impacts of climate-driven disease emergence.
Ecological Consequences of Sea-Ice Decline
Eric Post1,*, Uma S. Bhatt2, Cecilia M. Bitz3, Jedediah F. Brodie4, Tara L. Fulton5, Mark Hebblewhite6, Jeffrey Kerby1, Susan J. Kutz7, Ian Stirling8, Donald A. Walker9
After a decade with nine of the lowest arctic sea-ice minima on record, including the historically low minimum in 2012, we synthesize recent developments in the study of ecological responses to sea-ice decline. Sea-ice loss emerges as an important driver of marine and terrestrial ecological dynamics, influencing productivity, species interactions, population mixing, gene flow, and pathogen and disease transmission. Major challenges in the near future include assigning clearer attribution to sea ice as a primary driver of such dynamics, especially in terrestrial systems, and addressing pressures arising from human use of arctic coastal and near-shore areas as sea ice diminishes.
