Our world today stands at the brink of climate change catastrophe. Thanks to indiscriminate combustion of fossil fuels over the last two centuries, we have been heating our planet more than ever, and this could have far-reaching consequences for our current and future generations. Buried deep in the pages of history is a tale of the ruin of an empire and its city which — scientists say — could have been — in large part — driven by abrupt changes in the climate. The city of Angkor and its Khmer empire had to face their demise by prolonged periods of drought and intense rainfall. And that’s an important lesson for all of us who have been struggling to understand our role and responses on the face of imminent climate change.
Known as the medieval hydraulic city, Angkor in Cambodia, Asia, saw itself flouring between 900 and 1300 AD and then declining, primarily pushed by erratic and intense weather events. It was considered to be one of the largest cities in the world of the pre-industrial era. With its complex and unparalleled canal systems, forts and temples — it was home to over 750,000 people. Water was the mainstay of the Khmer empire and its ability to collect and store water in its canals and reservoirs for agriculture purposes was one of its strengths. However, within a matter of a few decades, this once mighty and prospering kingdom fell prey to rival neighbouring empires and sudden climate changes which blocked most of its canal systems with sand sediments and led its people to abandon it and move to the south to Phnom Penh.
Southeast Asia has highly seasonal rainfalls. In the space between the 14th and 15th century, the city of Angkor faced unstable extreme weather with prolonged periods of drought — which lasted decades — with instances of intense rainfalls in between, which wreaked havoc on the hydrological system of the city. Rainfalls eroded away the system, and severed the links, leading to choked canals and exacerbating the risks of further flooding. The efforts of Angkor engineers to control the flood by diverting it to the existing river systems proved futile as that created new catchments. That caused massive casualties and abandonment of the city by its ruler and people en masse.
The collapse of Angkor is not just one example of a climate change catastrophe in the past. The centre of Mayan civilisation for centuries, the city of Tikal, in Guatemala, Central America, had a somewhat similar fate. Deforestation and severe drought in the region led to the fall of civilisation in the mid 9th century. These pages from the history go on to show the magnitude of the threat climate change can present before us in future. Unless we take transformative measures to reduce our greenhouse gases emission into the atmosphere — which has been elevating the temperature of the earth and triggering extreme weather events such as floods, drought, storms, heatwaves, and other large scale changes like rapid melting of glaciers in the Arctic, warming and rising oceans — our future too seems nebulous from here.