2012年，超级风暴桑迪（Superstorm Sandy ）破坏了美国成千上万所房屋，对重要建筑造成数十亿美元的损失。(© AP Images)

很多人认为气候变化是其他地方发生的情况，只对其他人有影响。但是在美国很多沿海社区，人们正亲眼目睹气候变化造成海平面上升的现象。

美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration）高级官员霍利·班福德（Holly Bamford）说，“我们知道海平面正在上升，沿海社区更容易受极端气候和与气候相关的事态影响。”最近美国发表了一篇关于保护沿海结构的研究报告，霍利·班福德是共同作者之一。

腐蚀、极端气候事件和频繁的水患已经发生。自然条件为陆地设施提供了一定保护，有助于防止暴风雨和海水泛滥造成的危害，例如盐碱地、牡蛎养殖场、珊瑚礁、红树林、海草、沙丘和堰洲岛。这些自然屏障如果受到妥善保护，可以避免人工建造的设施受到海平面上升的危害。

自然屏障可以经过重新改造，形成防止海水侵蚀的缓冲地带，为人类的沿海建筑提供更长时间的保护。某些社区正将海堤后移，使自然屏障获得更好的立足点。

改造沿海结构有助于进一步增强对抗海平面上升的适应能力。有关社区还可以为保护建筑物建造海堤或水闸。这些行动如果能与现有或重建的自然屏障相结合甚至更为有效

报告认为，各沿海社区需要因地制宜选择防护措施，为寻求解决方案进一步开展研究，但重要的是必须采取行动。报告指出，“面对气候变化，换一种方式思考管理和保护美国海岸线的问题十分重要。”

美国总人口的40%生活在邻近海岸的地区，国民经济活动的大约一半在这些地区发生。 增强这些社区对抗气候变化的适应能力是全国性政策的一个重要组成部分。

全世界一半的人口在沿海或者邻近地区生活，所以制定适应性战略十分重要，世界各地的沿海城市尤其应该如此。

美国正在很多社会和经济部门 采取措施，努力降低导致气候变化的温室气体排放并努力实现清洁能源经济 。

A lot of people think climate change is something happening somewhere else to somebody else. But for people in many U.S. coastal communities, climate change is causing a rise in sea level right now, right in front of them.

“We know that sea levels are rising and that coastal communities are becoming more vulnerable to extreme weather and climate-related events,” said Holly Bamford, a top official at the National Oceanic and Atmospheric Administration (NOAA) and co-author of a recently published study about protections and barriers that can buffer seaside structures.

Erosion, extreme weather events and frequent flooding are already occurring. Nature protects the mainland from storm and coastal flooding with architecture of its own: salt marshes, oyster beds, coral reefs, mangroves, seagrass, sand dunes and barrier islands. If left in place, natural barriers protect man-made structures from sea level rise.

Natural barriers can be recreated to protect human infrastructure, providing a storm buffer and a longer life to seaside buildings. Some communities are moving their sea walls farther from the ocean, allowing natural barriers to regain a foothold.

Improvements to seaside structures can make them more resilient against a rising ocean, or communities may install sea walls or flood gates to protect buildings. These actions are even more effective when coupled with existing or recreated natural barriers.

No one solution will suit every coastal community, so potential solutions demand further research, the study finds. Still, the need to act is imperative. “In the face of climate change, it is critical to the health and prosperity of communities and the economy to think differently about managing and conserving U.S. shorelines,” the study says.

About 40 percent of the U.S. population lives near a coast, and just under half of national economic activity occurs in these areas. Building resilience against climate change in those communities is a critical element of national policy.

Half the world population lives on or near a coast, so resilience strategies could be widely valuable, especially in the world’s many seaside cities.

The United States is taking steps in many social and economic sectors to reduce greenhouse gas emissions causing climate change and move to a clean-energy economy.