一位僧人在仔细审视吴哥窟——已崩溃的高棉帝国的标志性寺庙群。在不到一百年的时间里，气候变化把这个寺庙群变成了一个被遗弃的村落。

——适应气候变化

作者：亚力山德拉·库斯托

“水是万物之源” ——希腊哲学家（泰利斯（Thales of Miletus），约公元前624-546

在我们思考未来时，我们往往忘记回顾我们的过去。当我的思维顺着泥泞的小径步入那据说曾经是辉煌的吴哥帝国（Angkor Empire）的废墟的丛林中时，那些倾圮的庙宇显然提醒着一个我们今天应该接受的教训。

从大都市到村落

当时，人口接近一百万的这个大都市是这个星球上最大的城市，高棉（Khmer）统治者设计了一个精妙的渠道与水库系统来储存雨季的雨水。有一个可预期的气候再加上这个可靠的基础设施，高棉帝国成了一个重要的农业国，并创造了大量财富，以致中国也派来了使节，而且，法国考古学家最近的发掘似乎显示，它的贸易活动甚至远达今天的伊朗。

可是，后来一切都改变了。树木年轮研究和在曾经是很有用的水库的泥淖中保存下来的花粉与植物标本描绘了这样一幅图景：在大约公元1350年，由于气候变更，那可靠的降雨模式发生了变化，有迹象显示，人们至少四次改造蓄水系统，来应对毫无疑问的一种连年干旱的气候模式。

没有可预测气候变化等重大变迁的先进设备，只有一个用石头砌成的蓄水系统，高棉人民根本无法快速改变他们的基础设施来因应该城市的缺水状况。走下枯竭的河床，看着那些古老的、用一度曾是神圣的庙堂里取来的精雕细刻的巨石建成的拱形堤坝的残迹，不难想象人们为适应变化所作的无望的努力。这种景象不由得你不寒而栗。在不到一百年中，那里只剩下一些小村落，人们纷纷逃离他们的伟大城市的黄金尖顶去寻找水源。

当今的水与气候变化状况

全球性气候变化是一个绝对的现实，再加上一个世纪以来的碳污染，我们当前面临的气候变化已经超越了已知的各种研究模型，并以急剧的步伐加速向我们逼近。就像在当年的高棉，人们将首先在水的方面感受到它的影响。在全球用水量增加与政治辩论进行的同时，全球各国均沿着与历史相撞的道路加速下滑 – 或许注定将被作为与标志着曾一度辉煌的高棉帝国的幽灵出没的废墟的墓志铭被记载下来：在一个气候变化的时期，以不能持续的方式使用资源、对关键基础设施的管理失当，以及对造水生态系统的破坏导致了崩溃。

当年的高棉人民可能并不明白他们面临的危险，但我们是清楚的。“水”是我们在本世纪面临的根本性挑战，除非作为水消费者的我们全体公民决心行动并大声疾呼，那些可能在将来审视我们的毁灭的人们将不会为我们的雄伟城市惊叹，而只会为我们所作的愚蠢选择而嗟叹。我敦促你们与我一起，不仅培养新习惯、采用新技术来节约水，并且坚持要求政府领袖们承诺推行有益于环境的气候政策。

亚历山德拉‧库斯托（Alexandra Cousteau）出身于具有航海和水资源保护传统的家庭，于2008年创建蓝色遗产国际（Blue Legacy International）组织，“注重通过展现水问题的相互关联，揭示我们这个水星球的动态”。该组织开发和推广传统式和新型的媒体项目，激励世界各地的人就至关重要的水问题采取行动。

A monk surveys Angkor Wat, the iconic temple complex of the fallen Khmer Empire. In less than a century, climate change transformed the complex into an abandoned village.

by Alexandra Cousteau

“Water sustains all.”
Thales of Miletus
Greek philosopher
ca. b.624 B.C.–d.546 B.C.

When we think about the future we all too often forget to look at our past. When my mind wanders down muddy pathways into the jungle that reclaims the ruins of the once majestic Angkor Empire, I am poignantly reminded that there’s a lesson in those fallen temples we should hear today.

From Metropolis to Village

The metropolis of nearly 1 million people was, in its day, the largest city on the planet. Khmer rulers engineered an ingenious system of canals and reservoirs to store water from the rainy season. With a predictable climate and reliable water infrastructure, the empire became a dominant agricultural producer and built wealth that drew ambassadors from China and, as recent excavations by French archaeologists seem to indicate, trade from as far away as modern-day Iran.

And then everything changed. Tree-ring studies, along with pollen and plant specimens preserved in the mud of the once great reservoirs, paint a picture: The dependable patterns of rainfall shifted sometime around 1350 due to climate change. Evidence indicates at least four efforts to alter the system to make up for what was no doubt thought of as a simple pattern of dry years.

Without sophisticated means of predicting an event like climate change and a water system quite literally set in stone, there was little the people of Angkor could do to alter their infrastructure fast enough to keep pace with the city’s thirst. It was chilling to walk down dry riverbeds and see falling ancient arches made of intricately carved stones stripped from once-sacred temples in a futile attempt to keep pace with the changes. In fewer than 100 years, only small villages remained as citizens fled the golden spires of their great city in pursuit of water.

Water and Climate Change Today

Global climate change is an absolute reality. Fueled by a century of carbon, our current climate change is already ahead of models and picking up speed at a dramatic pace. As in Angkor, its effects will be felt first in water. And while global consumption increases and politicos debate, the global community races down a collision course with history — possibly doomed to be remembered by the same epitaph that marks the ghostly ruins of the once great Angkor Empire: Unsustainable consumption of resources, mismanagement of critical infrastructure and destruction of water-shaping ecosystems during a period of climate change leads to collapse.

The Khmer people may not have understood what they were risking, but we do. Water is the defining challenge of our century, and unless we commit as consumers and speak out as citizens, those who someday examine our collapse will not marvel at the grandeur of our cities but at the foolishness of our choices. I challenge you to join me in not only embracing new habits and technology to conserve water, but in also insisting governmental leaders commit to meaningful climate policy.

Alexandra Cousteau, member of a family with a tradition of seafaring and water conservation, founded Blue Legacy International in 2008 to “tell the story of our Water Planet by focusing on the interconnectivity of water issues.” The organization develops and distributes traditional and new media projects to inspire audiences everywhere to take action on critical water issues.