In a storied career, the diplomat Professor Tommy Koh also chaired the Earth Summit in 1992 and negotiated the Law of the Sea.

Synopsis: Every first and third Sunday of the month, The Straits Times analyses the beat of the changing environment, from biodiversity conservation to climate change.

The framers of the United Nations Convention on the Law of the Sea did not foresee global warming affecting oceans to the extent that it does - causing acidification and the death of coral reefs - said the top diplomat who was president of the 1973 conference that produced the Convention known as UNCLOS.

In this episode, Singapore’s ambassador at-large and foremost international environmental law expert Tommy Koh - who also chaired the pivotal 1992 Earth Summit - tells host ST's global contributor Nirmal Ghosh that plastic debris in the oceans now is of severe concern. He adds that the international community has also failed to be good stewards of the world's fisheries.

According to the Food and Agricultural Organisation (FAO), unsustainable practices have depleted about 90 per cent of major fisheries - and fishing fleets continue to be subsidised. The total capacity of the world’s fishing fleets is beyond the sustainable limit of the oceans.

Meanwhile, unlike climate change, the loss of biodiversity has failed to capture the popular imagination even as some scientists are calling the current era "the sixth extinction."

There is hope, however, that the international community is at a tipping point, with people and governments waking up to the danger of this unprecedented loss.