华盛顿――为寻求较为凉爽的气候，动植物在向山区高地迁移。一些鱼类的活动范围和数量缩小。其他的物种因无法适应气候变化而数量越来越少，可能走向灭绝。

这些发现来自一项范围广泛的研究――《气候变化对生物多样性、生态系统和生态系统服务功能的影响》（Impacts of Climate Change on Biodiversity, Ecosystems and Ecosystem Services）。研究由来自美国地质调查局（U.S. Geological Survey）、学术界和侧重环保的非政府组织的科学家合作完成。

该科研小组集成了迄今有关候变化如何影响生态系统、这些生态系统为人类或其他生命形式提供的资源或实用功能、以及在这些生态系统内的生命多样性的了解。这份于12月18日发布的报告的结果将被纳入《国家气候评估报告》（National Climate Assessment）。根据法律规定，《国家气候评估报告》每四年向总统和国会提交一次。下次报告日期是2013年。

最新研究检视了来自美国全国各地的气候数据。这些数据显示，在降雨量、结冰天数、动物迁徙次数和物种繁殖习性方面发生了许多变化。亚利桑那州立大学坦佩校园（Arizona State University in Tempe）科学家、该项研究的主要作者之一南希•格林（Nancy Grimm）指出，这些变化正在“引发贯穿各生态系统的连锁效应。”

报告中的一个关键发现是，“越来越多的证据在显示可直接归因于气候变化的种群数量下降和局部灭绝。”

气候变化可能会打乱将各个生态系统物种交织在一起的生命网中的微妙平衡。温度升高可能使昆虫过早出现，从而使在季节性迁移中以新生幼虫为食物资源的候鸟无以食用。

与那些候鸟一样，我们人类也可能会发现，气候的变化会剥夺我们所依赖的资源。

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科学家在一头阿拉斯加白鲸身上安装了一个跟踪装置。水体污染和过度狩猎使得这种生物的生存受到威胁。

全国野生动物保护协会（National Wildlife Federation）气候学家、该项研究的另一位主笔阿曼达•施陶特（Amanda Staudt）说：“气候变化对于生态系统的影响对民众和社区会产生重大影响。”“气候条件的改变正在影响生态系统的实用功能，诸如沿海生物栖息地在抑制风暴潮方面所发挥的作用、或是我们的森林提供木材和帮助过滤饮水的能力。”

例如，暴雨频发会把更多的污染物冲向下游，从而改变饮水的质量或带来更大的水源性疾病威胁。

这项研究报告旨在向美国的政策制定者通报国内正在发生的这些变化，然而这并不意味着这些环境变化仅发生在美国。

施陶特在回复一封电子邮件查询时这样写道：“报告中详细介绍的美国的那些类型的气候变化绝对在影响着世界各地的物种和生态系统。”她指出，参与撰写本报告的60多位美国科学家中，有些人曾在其研究中参考了国际上的研究成果。

她引用了国际自然保护联盟（International Union for Conservation of Nature）的《濒危物种红色名录》（Red List of Threatened Species），其中确定了4,000多个受到气温升高、干旱加重的威胁和其它因气候变化而变迁栖息地的物种。这项研究表明，在所研究的4,000个物种中，29％受到极端温度的影响，28％受到干旱影响。

这项美国的研究表明，气候变化正在改变着具有重要商业价值的海洋鱼类数量和活动范围。美国地质调查局科学家及报告主要作者米歇尔•施陶丁格（Michelle Staudinger）说：“这些变化几乎肯定将会继续……从而导致一些本地渔场数目下降或消失，而另一些则可能增长并变得更有价值”――如果捕鱼业能够找到可行方式去适应变化的话。

《气候变化的影响》报告还明确肯定，气候变化是造成美国西部地区毁灭森林的野火和虫害的罪魁祸首。

报告指出，“积雪的巨大变化”、融化时间和土壤冻结频率，也正在给山区和相邻低地的土地和水域生态系统造成严重后果。

报告指出，找到适应方式对于保护多样化的物种和让保护环境者有效管理自然环境至关重要。报告作者之一、全国野生动物联合会负责气候适应研究的主任布鲁斯•斯坦因（Bruce Stein）说：“自然保护界正在努力探索”如何实现这一目标。

Scientists put a tracking device on an Alaskan Beluga whale. The creatures’ survival is threatened by water pollution and over hunting.

Washington — Animals and plants are moving up mountainsides seeking cooler temperatures. Some fish species have smaller ranges and less abundance. Other species are diminishing in their numbers, unable to adjust to climate change, with extinction being a possible outcome.

These findings come from a wide-ranging study — Impacts of Climate Change on Biodiversity, Ecosystems and Ecosystem Services — produced by a collaboration of scientists from the U.S. Geological Survey (USGS), academia and environmentally oriented nongovernmental organizations.

The scientific team synthesized current understanding of how climate change is affecting ecosystems, those resources, or services, that ecosystems supply to humans or other life forms, and the diversity of life within those ecosystems. The report, released December 18, is one resource that will be used in a National Climate Assessment that is prepared by law for the president and the U.S. Congress every four years and due in 2013.

Examining climatic data from all over the United States, the report shows many shifts in rainfall, freeze dates, animal migration times and species reproduction habits. These changes are “causing cascading effects that extend through ecosystems,” said Nancy Grimm, a scientist at Arizona State University in Tempe and a lead author of the study.

One key finding of the report reveals “increasing evidence of population declines and localized extinctions that can be directly attributed to climate change.”

Climate changes may disrupt the delicate balance in the web of life that binds the species of individual ecosystems. Warmer temperatures might make insects emerge too early for migrating birds that rely on the newborn bugs as a food source in their seasonal travels.

Like those migrating birds, we humans could also find that climate shifts deprive us of a resource on which we depend.

“The impact of climate change on ecosystems has important implications for people and communities,” said Amanda Staudt, a climate scientist at the National Wildlife Federation and another lead author on the report. “Shifting climate conditions are affecting ecosystem services, such as the role that coastal habitats play in dampening storm surge or the ability of our forests to provide timber and help filter our drinking water.”

For example, frequent torrents of rain can push more pollutants downstream, changing the quality of drinking water or posing a greater threat of waterborne disease.

The purpose of the report is to inform U.S. policymakers on how these changes are unfolding domestically, but that doesn’t mean these environmental changes are unique to this country.

“The sorts of climate impacts that the report details for the United States absolutely are affecting species and ecosystems around the world,” Staudt wrote in response to an email inquiry. She said that some of the more than 60 U.S. scientists involved in this report consulted international studies in their research.

She cites the International Union for Conservation of Nature's Red List of Threatened Species, which has identified more than 4,000 species threatened by increased temperatures, harsher droughts and other climate-related shifts in habitat. The research shows temperature extremes affecting 29 percent of the 4,000 species studied and droughts affecting 28 percent.

The U.S. research shows that climate change is shifting the abundance and geographic range of commercially important ocean fish. “These changes will almost certainly continue,” said Michelle Staudinger, a USGS scientist and lead author, “resulting in some local fisheries declining or disappearing while others may grow and become more valuable,” if the fishing industry can find an acceptable way to adapt to change.

Impacts of Climate Change also finds with high certainty that climate change is a top cause of wildfire and tree insect outbreaks that are killing forests in the western United States.

“Profound changes in snowpack,” the timing of melting, and the frequency of soil freezing are also causing serious consequences for land and water ecosystems in mountains and adjoining lowlands, the report finds.

Identifying ways to adapt is vital for the conservation of diverse species and effective management of natural environments by human environmental caretakers, the report says. “The conservation community is grappling” with how to achieve that end, said contributing author Bruce Stein, director of climate adaptation at the National Wildlife Federation.