Whether Thomas Malthus will have the last laugh will be known in around 50 years. For most of the past few decades, powered by the confidence of the Green Revolution, we have been laughing at the Malthusian paranoia of population growth outstripping food production. World population has grown from around three billion in 1960 to around 6.8 billion today. But food production has kept pace.

Despite this achievement, the number of hungry, undernourished people in the world has grown from around 900 million to roughly one billion—a fall in the percentage, but an absolute increase. This is a failure, and most of us recognize it as such. Availability of food is not really the issue; it’s a market and governance failure. And our slowness in solving the problem is strange and reprehensible.

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This delay is not because of a lack of recognition of the problem. Globally, feeding the hungry is a key issue, not only for governments, but also for civil society. However slowly, the world’s might is working on this, driven by ethical, political and emotional concerns.

Yet, most of us do not realize that this equilibrium on the food front, with one big recognized problem to solve (with seemingly known solutions), is the calm before a storm.

To peep into the eye of this storm, here’s a thought experiment: Let’s go back to 1960, and in that pre-Green Revolution world, look at ways to increase food production, with the knowledge that world population would increase by around four billion in 50 years. How would we feed the extra mouths?

Now let’s impose some constraints on this experiment: As we try to boost food production, we cannot damage and deplete underground aquifers, nor overground water bodies, meaning we cannot draw more water than the rate of recharge. We cannot leach the soil. We cannot use fertilizers that increase the yield but pollute the life chain, damaging health, biodiversity and the soil. We cannot use pesticides that also pollute the life chain and environment, and eventually make the pests resistant. We cannot cut down more forests to increase agricultural land. We cannot mono-crop our farms, opening them to unknown risks. We cannot use so-called “high-yielding varieties", which are really “highly responsive varieties"—highly responsive to more irrigation and more fertilizers. We would still have to grow enough food for another four billion people.

But we did not do it this way. The Green Revolution had none of these constraints. In fact, world agriculture continues to operate with only tenuous consideration (if at all) for these issues.

But we have no choice but to have these constraints. That’s why the storm is brewing. The damage to environment and life from irrigation-profligate, fertilizer- and pesticide-intensive, mono-cropped, land-hungry agriculture has made feeding 6.8 billion mouths unsustainable. We do not see this deep damage every day; and so, we never ask the question—“how can we feed the 6.8 billion, with no damage to life and environment?" In fact, some of the key architects of the Green Revolution were the first to point out these problems with the way the Revolution actually unfolded.

To sense the full intensity of this brewing storm, we need to consider three more crucial (and closely entwined) fronts.

First, world population will grow to around nine billion by 2050. So this “constrained" agriculture—let’s call it sustainable agriculture—will have to produce enough food for all these people. As of now, we don’t even know how to do it for the 6.8 billion.

Second, we have to consider both the cyclical effects of current agriculture methods on climate change and vice versa. Depending on how you measure it, between 15% and 20% of man’s green house gas (GHG) footprint comes from agriculture—around the same amount that comes from industry.

Estimates vary, but there seems to be reasonable consensus that climate change will affect—though unevenly— global crop yields. There will be a significant fall in yields, without factoring in the effect of the chronic water scarcity that will develop.

Third, as populations grow out of poverty (around three billion people over the next few decades), and become wealthier, the demand profile of food changes, accordingly driving a change in agriculture output. The shift is to more protein-intensive food, i.e., from grains to meat and milk-based products. This significantly increases the ecological strain from agriculture. For example, the GHG footprint of the average Indian food basket is less than 1 tonne per capita, and that of the average American around 8 tonnes per capita.

The minority conscious of this brewing storm believes that with intense effort, we can deal with it, because we have the understanding and the technology. But how can this happen, when the majority of us are not even conscious of the problem? Place that in the context of how long it is taking to solve the one problem regarding food that we recognize globally—that of feeding the hungry billion.

If we don’t want Malthus to have the last laugh, we will have to make sustainable agriculture (what that could be is the subject of another column) as big a global priority as countering terrorism or driving economic growth.

Anurag Behar is co-CEO of Azim Premji Foundation and also leads sustainability initiatives for Wipro Ltd. He writes every fortnight on issues of ecology and education. Comments are welcome at othersphere@livemint.com