For a few weeks last month, the usually pristine skies over Singapore were covered with smog so thick I could have mistaken my hometown for a Chinese city such as Hong Kong or even Beijing.

Singapore and Malaysia endure a period of smoke haze every year as a result of the slash-and-burn methods used by farmers in Indonesia. This year was exceptionally bad because of dry weather and children, the elderly and people with chronic illnesses in the city state were advised to stay indoors.

When Indonesia burns, its immediate neighbours suffer, but there was a time when a geological event that occurred there had an impact on places as far away as the Yangtze River Delta. In the spring of 1815, a series of massive volcanic eruptions at Mount Tambora, on the island of Sumbawa, in the Dutch East Indies (modern-day Indonesia), created ash clouds that covered much of the northern hemisphere. With less sunlight penetrating the dense clouds, global temperatures fell and 15 years of climatic fluctuations followed.

According to renowned economic historians such as Li Bozhong, the Yangtze River Delta, China's breadbasket, was severely affected. The area saw two devastating floods, in 1823 and 1833, resulting in massive crop failures. Some argue that the social unrest those failures unleashed marked the beginning of the end for the Qing dynasty.