Recycle water to avoid Malthusian spectre, says expert

Cautioning against the “reappearance” of the Malthusian spectre – that the Earth cannot indefinitely support an ever-increasing population-, noted water expert, Prof P M Natarajan, strongly urged that recycling water resources has become a must to ensure the earth’s “carrying capacity”.

Though advances in agriculture technologies and “Green Revolutions” have proved doomsday predictors wrong, the Malthusian predicament of “how many human beings can the earth support before resources run low and Nature takes over” is still relevant as “global water availability” has become a critical factor, Prof P M Natarajan said, voicing key concerns on “World Water Day” on Friday.

Sharing some of his insights with Deccan Herald, Prof Natarajan, a former member of the Tamil Nadu Planning Commission and presently Director, Centre For climate Change, Periyar Manniyammai University, Thanjavur, said there have been several estimates by scientists since 17th century on how many human beings can “Mother Earth” sustainably support- called the ‘carrying capacity’.

Citing research studies by scientists, he said the ‘more serious recent estimates’ put the earth’s ‘carrying capacity’ as ranging from 1 to 2 billion people to 30 billion people, “existing on minimum rations and using every available hectare of suitable land for high-intensity food production”. The world’s population (2012) has been put at almost 7.1 billion people.

The factors constraining the people ‘carrying capacity’ continue to be water, food and land. Pointing out to a University of Zaragoza in Columbia Study, the expert said the present water resources on earth has been put at 1386 cubic million km in volume, of which ‘fresh water’ availability is 42,000 cubic km and ‘dependable water resource’ at just 12,000 cubic km.