Text of my ‘When Worlds Collide’ column published in Ceylon Today Sunday newspaper on 3 June 2012

World Environment Day is once again being observed on June 5.

It’s 40 years since the first UN Conference on the Human Environment was held in Stockholm, Sweden, in June 1972, which led to the founding of the UN Environment Programme (UNEP). I was too young to remember anything of that event. But what happened exactly 20 years later is unforgettable.

World leaders – including Lankan Prime Minister D B Wijetunga – had converged to Rio de Janeiro, Brazil, for the Earth Summit. As they debated the fate of the planet, Greater Colombo received the heaviest rainfall in living memory: 492mm, or more than one-eighth of its annual rainfall, all on a single night.

World Environment Day 1992 dawned with many areas in and around Colombo under water. That flash flood cut across…