紐時賞析／高溫、洪水來襲⋯極端氣候惹禍 全美橋樑崩塌風險增

连结南达科他州北苏瀑市与爱荷华州苏瀑市的一座大桥，在河水暴涨后于6月坍塌。（纽约时报）

Extreme Weather Is Increasing Risk of Collapse for U.S. Bridges

极端气候惹祸 全美桥梁崩塌风险增

On a 35°C day this summer, New York City’s Third Avenue Bridge, connecting the Bronx and Manhattan, got stuck in the open position for hours. As heat and flooding scorched and scoured the Midwest, a steel railroad bridge connecting Iowa with South Dakota collapsed under surging waters. In Lewiston, Maine, a bridge closed after the pavement buckled from fluctuating temperatures.

纽约市连结布朗克斯与曼哈顿的第三大道桥，在今夏气温达摄氏35度的某天卡在开启状态数小时。随着高温与洪水席卷中西部，连结爱荷华州与南达科他州的一座火车铁桥因河水暴涨而坍塌。在缅因州路厄斯顿市，气温起伏导致路面变形，一座桥梁被迫封闭。

America’s bridges, a quarter of which were built before 1960, were already in need of repair. But now, extreme heat and increased flooding linked to climate change are accelerating the disintegration of the nation’s bridges, engineers say, essentially causing them to age prematurely.

四分之一美国桥梁建于1960年以前，原已需要整修。但如今有关气候变迁的极端高温与更频繁洪水正加速该国桥梁解体，工程师说，实质上造成它们提前老化。

The result is a quiet but growing threat to the safe movement of people and goods around the country, and another example of how climate change is reshaping daily life in ways Americans may not realize.

结果是对全美民众和货物的安全运输带来寂静但与日俱增的威胁，也再次显示气候变迁正以美国人可能没有发觉的方式重塑日常生活。

“We have a bridge crisis that is specifically tied to extreme weather events,” said Paul Chinowsky, a professor of civil engineering at the University of Colorado Boulder who researches the effects of climate change on infrastructure. “These are not things that would happen under normal climate circumstances. These are not things that we’ve ever seen at this rate.”

研究气候变迁对基础设施影响的美国波尔德科罗拉多大学土木工程教授奇诺斯基说，「我们正面临一场与极端气候事件紧密相连的桥梁危机。这不是正常气候条件下会发生的事情，这不是我们曾见过以这种速度发生的事情」。

Bridges designed and built decades ago with materials not intended to withstand sharp temperature swings are now rapidly swelling and contracting, leaving them weakened.

几十年前设计与建造的桥梁，使用的建材并未预期须承受气温剧烈变化，如今快速热涨冷缩让其变得脆弱。

“It’s getting so hot that the pieces that hold the concrete and steel, those bridges can literally fall apart like Tinkertoys,” Chinowsky said.

奇诺斯基表示，「气温变得这么热，支撑混凝土与钢材的组件和那些桥梁可能像积木一样解体」。

As temperatures reached the highest in recorded history this year, much of the nation’s infrastructure, from highways to runways, has suffered. But bridges face particular risks.

随着今年气温创历史新高，从高速公路到机场跑道，全美许多基础设施受到影响，但桥梁面临特别的风险。

A study in the journal PLOS ONE found that extreme temperatures resulting from climate change could cause 1 in 4 steel bridges in the United States to collapse by 2050. By 2040, failures caused by extreme heat could require widespread bridge repairs and closures, researchers found.

刊载于PLOS ONE期刊的一项研究发现，到2050年，气候变迁导致的极端气温恐让美国四分之一钢桥坍塌。研究人员发现，到2040年，极端高温造成的故障，可能导致广泛的桥梁维修与封闭。

Studies show that climate change has caused more rapid shifts between extreme heat and cold, said Royce Floyd, a professor of engineering at the University of Oklahoma. Those seesawing temperatures can cause pavement to squeeze from both sides onto a span, forcing the road and steel to buckle or crack, or even pushing steel beams out of alignment, Floyd found.

奥克拉荷马大学工程教授佛洛伊德表示，研究显示，气候变迁导致极端热与冷之间更加迅速转变。佛洛伊德发现，那些气温来回变化，可能造成路面由两端挤压桥梁，迫使道路与钢材弯曲或龟裂，甚至导致钢梁错位。

文／ Coral Davenport 　译／江昱蓁