There is little doubt that climate change threatens Panama.

Rising seas will submerge the low-lying Caribbean islands of San Blas, a tourist attraction and home to several thousand Guna, an indigenous group.

Warmer temperatures will speed evaporation, and thus reduce water levels in Lake Gatun.

But pinning blame for recent droughts on climate change is harder.

毫无疑问，气候变化威胁着巴拿马。

海平面不断上升，加勒比海上低海拔的圣布拉斯群岛(San Blas)将被淹没，这里既是旅游胜地，也是数千名土著古纳人(Guna)的家园。

气温升高将加速蒸发，进而降低加通湖的水位。

但越来越难将近年的干旱归咎于气候变化。

Panama’s worst droughts have happened during extreme occurrences of El Niño, a natural phenomenon in which warm water moves eastwards across the equatorial Pacific Ocean.

Longer cycles like the Pacific Decadal Oscillation, which alternates every 20-30 years between warm phases that make El Niños stronger and more frequent and cooler ones, make the role of climate change harder to discern.

巴拿马最严重的干旱都发生在极端厄尔尼诺现象期间，这是一种温暖海水流向赤道东太平洋的自然现象。

周期更长的自然现象让气候变化的影响更难辨别。

比如太平洋十年涛动，其暖相位和冷相位的变换周期为20至30年，涛动处于暖相位时厄尔尼诺现象会更强、更频繁。

Residents of the capital do not doubt that changes are afoot.

The rainy season once brought daily showers of three to four hours.

Now the same amount of rain falls in an hour.

Eight of the ten biggest storms in the city, measured by rainfall within 24 hours, have occurred since 2000.

Despite those downpours, the canal area has had six straight years of below-average rainfall.

The dry season is lengthening.

This year it began a month earlier than usual and ended a month late.

The current drought is the first severe one to occur in a mild El Niño year.

巴拿马城的居民毫不怀疑即将发生的变化。

过去，雨季每天有三到四个小时的降雨。

现在，一小时内就有同等降雨量。

巴拿马城24小时内降雨量最大的十次暴雨中有八次发生在2000年以后。

尽管暴雨频发，但运河地区的降雨量已经连续六年低于平均水平。

旱季正在变长。

今年的旱季提前了一个月到来，又晚了一个月结束。

当前的干旱是首次在厄尔尼诺现象温和的年份里发生的严重干旱。

This unprecedented concurrence suggests that climate change is directly responsible, the ACP believes.

To be completely sure you’d have to wait a hundred years,” notes Carlos Vargas, the ACP’s vice-president for water and environment.

And even if climate change is not the culprit now, it may strengthen future El Niños, which would lengthen droughts and increase their intensity.

Some scientists think that if, as expected, the equatorial eastern Pacific warms faster than other regions, extreme El Niños will double in frequency to once a decade by 2100.

ACP认为，这种前所未有的并存现象表明气候变化是直接原因。

ACP水与环境事务副总裁卡洛斯·瓦尔加斯(Carlos Vargas)指出：要百分百确定这一点还得等一百年。

”而即使现在气候变化还不是罪魁祸首，它也可能在未来加剧厄尔尼诺现象，让干旱延长并加重。

一些科学家认为，如果如预期的那样，赤道东太平洋的升温速度快于其他地区，那么到2100年，极端厄尔尼诺现象出现的频率将翻倍，达到十年一次。

Water shortages imperil the canal’s expansion plans.

In 2016 a new set of locks allowed the passage of NEOPANAMAX ships.

The canal needs another upgrade to accommodate new ultra-large” vessels.

But work cannot start while water levels are so uncertain, ACP officials say.

水资源短缺危及运河的扩建计划。

2016年，一组新船闸建成，新巴拿马型”船只得以通行。

为了能让新的超大型”船只通行，运河还需要再次升级。

但ACP的官员表示，水位如此不确定，无法开启升级工作。

If droughts become frequent, shipping firms may favour more reliable routes between the Atlantic and Pacific oceans, such as rail lines across the United States.

Someday, climate change could open up for navigation the ice-clogged Northwest Passage through the Arctic.

That would cut by about 4,000km (2,500 miles) the length of a journey from Shanghai to New York, which is 19,500km via Panama.

如果干旱频发，船运公司可能会选择大西洋和太平洋之间更可靠的路线，例如穿越美国的铁路。

未来，经过北极冰封海域的西北航道可能会因气候变化变得适于通航。

届时，从上海到纽约的航程将减少约4000公里，而经巴拿马运河需航行1.

95万公里。

To secure the canal’s future, the ACP has to plan now.

We cannot go back to what we had in the past,” says Mr Vargas.

Already the ACP has stopped producing hydroelectricity from the Gatun dam.

It is studying ways to raise water levels, including by digging a third artificial lake to supply Panama city and piping water from the Indio river to Lake Gatun.

They’re going to have to do all of them,” says Merei Heras, a former environment minister, sipping a drink in a café as rain pelts down.

Deepening Lake Gatun is not an option because the mountains nearby would collapse.

为了确保运河的未来，ACP必须立即制订计划。

瓦尔加斯说：我们没法再回到从前。

”ACP已经停止了加通大坝的水力发电，现在正在研究提高水位的方法，包括挖掘第三个人工湖为巴拿马城供水，以及从印第奥河(Indio)向加通湖送水。

这些项目都得上。

”前环境部长梅雷·赫拉斯(Merei Heras)在咖啡馆里啜着一杯饮料说，外面大雨如注。

加深加通湖是行不通的，因为附近的山体会崩塌。

Drought-proofing the canal will be disruptive, forcing people to move and hurting habitats down-river from water-diversion projects.

Panama’s only answer to the global havoc caused by climate change, it seems, is to do local damage.

给运河做防旱工程将产生破坏性后果，迫使人们搬迁，损害引水工程下游的自然环境。

看来，巴拿马运河应对气候变化造成的全球性破坏的唯一办法就是在当地搞破坏。

【巴拿马，暴雨频发，雨量不足查看网站：[db:时间]】