A rot to answer: Mridula Ramesh links food loss, climate and cooking gas

Both organizations agree that we are losing and wasting too much.

Globally, food grown in an area larger than the Indian subcontinent is lost at the farm level every year. In India alone, the water contained in food wasted between farm and retail sales can meet the country’s domestic water needs.

Most losses occur before the crop leaves the field, either because it is left unharvested, improperly harvested, or is damaged in the process. Again, unlike Punjab, markets in most parts of India are not close to farms; Distance and poor logistics mean the smallest farmers in the poorest states suffer the most.

The scale is amazing. India loses (not wastes) enough rice to feed 70 million people every year – and rice is one of the crops with the lowest losses. Then there is more loss between mandi and retail. But even this pales in comparison to how much we waste at home, in restaurants, offices and retail stores.

When my Sundaram Climate Institute studied the impacts of food waste, we found that no one wants a garbage dump near their home. Why would they do this? These rotting mounds emit methane, attract stray animals, become breeding grounds for mosquitoes, and spew smoke (especially when garbage dumps are set on fire), which, as I noted in an earlier column, triggers chronic inflammation, among other things.

A commonly cited number for carbon emissions associated with food loss and waste (FLW) is 8% to 10% of global greenhouse-gas emissions. Seen this way, if global FLW were a country, it would emit more than India.

Meanwhile, a study published in the journal Nature Food in 2023 on cradle-to-grave emissions from food systems found that FLW accounts for 9.3 billion tonnes of CO2-eq emissions – or, a full 18% of global emissions, more than any country except China.

Now compare the outrage directed at a coal plant against the relative silence around FLW. The problem lies in that contradiction.

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Loss and wastage of food is a bad thing. Everyone knows this. Why do we underestimate its potential?

Is this because it masquerades as a municipal or farmer’s problem, when it is actually a geostrategic and climate issue? Or is it because in order to solve the problem we have to acknowledge our role in it, and actually work on being part of the solution?

The problem may be solved. The first step to change is better data. In 2022, the Government of India commissioned NABCONS (consultancy service of the National Bank for Agriculture and Rural Development, or NABARD) to survey 68,453 respondents across the entire supply chains – farmers, wholesalers, retailers, transporters, processors, storage operators – to map losses between the field and the store. This was a huge effort, but two problems limited its usefulness.

The first is old data. In my textile factory, I cannot expect today’s production to improve with data from three months ago, let alone three years ago. The same logic holds: reducing food losses requires ongoing monitoring, not a once-a-decade survey. Consider a continuous glucose monitor to manage diabetes.

The second is sampling. NABCONS randomly included 10 farmers from each village in its study. But not all farmers suffer equally. Agricultural economist Ashok Gulati and his colleagues at the Indian Council for Research on International Economic Relations (ICRIER) found in a 2024 study that the smallest farmers suffer the most in the transition between farm and market. A sample unaware of that skewness will underestimate losses exactly where they are worst. If I calculate my production based on data from my best machines, my factory will shut down.

Meanwhile, losses between sector and market – 72 freight trains a day, which is a conservative estimate – are costing the country, according to 2022 NABCONS data ₹1.52 lakh crore annually. Or roughly how much the central government spends on education.

This is mainly a cost borne by the farmer.

The Ministry of Food Processing Industries, whose budget is about 1/50th of that figure, commissioned a study that tells us this. This is a tragedy.

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Food loss is only part of the story. Homes, restaurants and offices generate 40% to 60% of FLW as waste. Here, the data is still thin. Managing these millions of tons of waste is a difficult task.

It is easy to control the weight of 17 kg. Why 17 kg? Because 11 years ago my house used to send this every day. And the lessons learned from reducing it to less than 700 grams are applicable to managing the millions of tonnes produced daily in our cities.

When I started managing my waste, I didn’t know how to get started. So, taking a cue from my factory, I started with measurements. I still keep daily logs in a slightly cumbersome Excel sheet. I’ll spare you the details (they’re in my 2018 book, The Climate Solution), but the core of it is this: Gather detailed data, and don’t lie to yourself.

Within a few weeks, patterns began to emerge. We learned that we generate around 17 kg of waste every day, most of it from the garden, while inside the house, the kitchen was the epicenter of the waste.

By then, I had become familiar with solutions in this area (and had begun to invest in some of them), and knew that the chemical key to turning waste into value lay in separating it into wet and dry, so that each could be processed separately. But how to do it?

The Japanese philosophy of poka yoke or idiot-proofing, which we practice in the factory, came to the rescue: design for ease of use, not virtue-signalling. This was possible only by observing how and when the waste was generated. What worked for us were three dustbins, placed side by side, without lids: one for rotten food and leftovers (which goes to the biogas plant), another for compostable materials including food and packaging, and the last for dry waste.

Now separation did not require extra seconds. The next big lesson was that no move should be smelly or unpleasant; It should all be so clean and so easy that no one has to summon the willpower or discretion to follow the new rules.

Once the waste was separated the solution was easily found. We tried anaerobic composting for some time before switching to a biogas plant. It’s less cumbersome, eliminates almost all of our food waste, and produces a little less than one cylinder a month (which is especially good at a time when everyone is worried about cooking gas).

Garden waste and biodegradable packaging goes into the compost bin, creating garden fodder that helps reduce the amount of water used in the garden. Why? As we saw in the previous column, each additional gram of carbon in the soil helps it store more water.

There are no flies or insects on open dustbins because the waste is managed periodically.

Each process is designed to be easy to follow, and hence easy to follow. We have had many dignitaries – ministers, activists, professors and diplomats – come up to us and peek into our dustbins and I ask them to get closer to the biogas plant (a little bigger than a domestic fridge) and take a deep breath. It has no smell.

And so, the system has persisted. In 11 years, a single household has kept over 55 tonnes of waste out of landfills, while also generating biogas, compost and even some cash (dry waste has an active market in India). The principle is simple: design for ease, based on granular data. Accuracy matters. This would never have happened if we did not know exactly where, when and what type of waste we produced.

The approach is scalable. Indore, which has successfully implemented waste segregation, converts more than 500 tonnes of wet waste a day into compressed natural gas (CNG) and powers 400 city buses with it, diverting the remaining gas to the domestic sector. Through this system it is also earning crores of rupees in the form of carbon credits.

I have invested in a company called Carbon Masters which converts over 100 tonnes of wet waste per day into biogas which it supplies to restaurants in Bengaluru and parts of Telangana. Amid the Middle East crisis, they have seen a surge in demand. Last week, I called Som Narayan, one of the co-founders. To my surprise, he didn’t pick up; Even more unusually, did not call back. When I finally managed to reach him, the excitement in his voice was palpable. “Sorry,” he said. “I’ve been on call until 10.30pm. For the first time in ten years, customers are calling us.”

Som told me that the Bengaluru Municipal Corporation is actively helping resolve supply logistics issues and discussing long-term contracts, which could help the company scale. Carbon Masters also makes fertiliser, another major, heavily subsidized import.

I asked him, what would happen if the Strait of Hormuz opened tomorrow? “It doesn’t matter,” Soma said. “Governments and customers are realizing that it is foolish to rely on any one energy source, and an imported energy source at that.”

Let’s be honest: It’s time to rethink our approach. The technology is here; Markets exist. Why aren’t there companies like Carbon Masters in every city? Why is Indore still relatively unique? One reason is that waste management is not seen as strategically important. Secondly, rebates and subsidies have only served to distort price signals and blunt the market’s ability to innovate. The third is the governance system and financial capacity of cities.

If we have to burn garbage, why would we collect data on it? And why wouldn’t we burn it when we see that it has no value?

If we are serious about climate, we must use markets to lead us in new directions. Will there be short-term pain? Definitely. But the likely outcome is a balance, including greater energy-independence, better climate resilience, stronger farm incomes and cleaner cities. It’s worth the compromise.

(Mridula Ramesh is a climate-tech investor and writer. She can be reached at tradeoffs@climateaction.net. Views expressed are personal)