Cane and able: Can sugar find a greener future, asks Mridula Ramesh

Piping hot tea, a dash of milk, a spoonful of sugar; stir and sip. The world recedes as the not-quite-scalding liquid floods the mouth. The bitter, brown brew, softened by milk and balanced by a fugitive sweetness at the edges of the tongue, makes for a heavenly cup. 
India is the home of cultivated sugarcane. “Iksu” is Sanskrit for sugarcane and it is said that Rama and the Ikshvaku clan may well have drawn their wealth, and their name, from sugarcane.
There are mentions of it in the Vedas and in early Buddhist and Tamil literature. The latter poetically portrays sugarcane as Kama’s bow (Kama being the Hindu god of love). The Arthashastra are replete with references to large-scale cultivation of this crop. Ayurveda, which is centred on balance, speaks of different sugars and their uses. Which raises the question: Are we in balance with sugar – in our food, our farms and our country’s climate plan?
Food
In a popular Huberman Lab podcast, Chilean geneticist and neurobiologist Charles Zuker discusses an experiment in which mice without taste receptors initially responded with equal indifference to both regular and sugared water. After 48 hours, however, the mice preferred the sugared water, even though they couldn’t taste it.
Scientists believe this is because the mice had developed a craving for the substance. And that happens because sugar activates the mesolimbic dopamine system (MDS), an ancient but diabolic pathway in the brain that rewards us for actions that help us stay alive.
Sugars are an efficient calorie source, so when we eat them, our brains flood with dopamine, telling us we did well. To receive the same rush of pleasure, though, we must consume more sugar the next time, which puts us on the road to sugar addiction.
Over decades, sugar’s image has yo-yoed. Today, it is considered Dietary Enemy #1, linked to obesity, metabolic dysfunction and Type 2 diabetes. Diabetes is a chronic illness and one of the ten top causes of death worldwide. South Asians are particularly vulnerable. In 2021, the International Diabetes Federation estimated there were 77 million adult diabetics and 25 million prediabetics in India alone.
I have relatives who have been diabetic for decades, and whose health depends on daily monitoring and management. Sadly, nearly half of Indian diabetics are unaware of their illness, leaving them more vulnerable to significant health issues.
The prevalence of Type 2 diabetes in India has risen from 2.1% in the early 1970s to 6.7% in 1990 and 8.7% in 2016. More than 13% of adults in Tamil Nadu, a diabetes hotspot, suffer from the disease. According to a 2021 study published in The Lancet, being overweight is the most significant risk factor for diabetes, followed by diet.
So, how has our diet changed?
From 1990 to 2016, official figures reveal we are eating less cereal (both grain and pulses) and far more edible oil, eggs, milk and sugar. Moreover, the average Indian household spends far more on processed food and sugary drinks today than it did in 1990. This mirrors diet-disease patterns reported in reviews published in journals such as The Lancet and Nature, which indicate that not eating enough whole grains, while ingesting too much refined grain, red meat, processed meat, and too many sugary beverages, are associated with higher risk of disease.
Maybe excess calories lie at the root of the problem, and sugary beverages and other naked carbohydrates (those without the fibre to fill us up) make it easier for us to consume more calories than we should?
“While developing diabetes is a multi-factorial process, there is no getting away from the fact that carb load plays a big role, and within carbs, sugar — both overt and hidden — play an important role,” says Cambridge-trained endocrinologist and diabetologist Dr Anand Kumar. Labelling food to inform customers of hidden sources of sugar and other ingredients may help.
But there appears to be more to this story.
One study found that Indians living in Chennai had a far higher diabetes prevalence than South Asians living in San Francisco and Chicago. Having lived in all three regions, I wonder if, aside from diet, exercise and environmental factors (such as inflammation caused by dioxins from burning garbage) also play a role.
If so, focussing on sugar alone will not solve the problem.
Farms
In the context of farms, let us ask: Is sugar a water villain?
The Commission for Agricultural Costs and Prices has found that sugarcane cultivation, which occupies less than 4% of Maharashtra’s cropped area, uses about 70% of its irrigation water. This causes severe water inequity in the state. Can we change this? How?
The sugar farmer and sugar industry depend on both cane yield (cane per acre) and recovery (sugar per tonne of cane), which are, in turn, affected by temperature and soil moisture. The crop thrives in hot, humid conditions and is well-adapted to India’s climate. But, alas, the climate is changing.
“When temperatures exceed 40 degrees Celsius, we have to give the plant enough water or it will get dessicated and the result will be very bad,” says Shanmuga Sundaram, head of R&D at EID Parry, one of India’s largest sugar producers.
Up to a point, the plant can cool itself with more water, but above 42 degrees Celsius, even with extra water, yield falls. That kind of temperature is becoming more common, especially in El Nino years, and especially in dry parts of peninsular India. And so, in 2023-24, an El Nino year, India’s sugar production fell sharply.
Meanwhile, sugarcane impacts climate too. Brazil, the 800-pound gorilla of sugar, is the plant’s adopted home. Cultivators began clearing rainforests here for the cash crop in the 16th century. Other crops followed. By the year 2000, Brazil had lost forest cover the size of France, in the Amazon. This has global climate consequences.
Closer to home, flooded sugarcane fields in India emit methane, a greenhouse gas 28 times stronger than carbon dioxide. By switching from flood to drip irrigation, studies have shown that methane emissions from paddy fields fall by about 80%. Could this be similar in sugarcane? We would need to test and see.
Fertiliser use raises carbon emissions and pollutes water too. Post-harvest residue-burning adds to the crop’s carbon footprint. Sugar mills crush cane numerous times and boil the juice to produce our sugar, which requires energy. When this energy is produced by burning sugarcane waste or bagasse, that makes the process carbon-neutral. If the mill recycles its waste water, that helps too.
By using less chemical fertiliser, mulching (rather than burning the waste), and crushing sugarcane only once — as in the production of the more-nutritious jaggery — we may make sugarcane greener. (Jaggery uses half the electricity while generating almost twice as much bagasse as sugar.)
“But going natural makes yield fall, so to make farmers bite, this would have to be incentivised,” says Muthiah Murugappan, CEO of EID Parry.
Perhaps if fertiliser wasn’t so heavily subsidised, and water and carbon were valued more highly, farmers would have been nudged that way automatically, and, with some luck, sugarcane farming would have been more sustainable.
To change the equilibrium, EID Parry engaged Cultyvate, a precision agri-water startup, to help reduce water consumption. Farmers hesitated to pay for the required technology; they saw no need to. The water it would save came to them free.
Eventually, EID Parry funded a pilot programme, with an eye on climate resilience. After a year, data revealed that flooding a field required 240,000 litres of water per acre, which dropped to 35,000 litres per acre when drip irrigation was used instead.
Because flooding required so much water (it’s like using a chainsaw on a pastry), it could be repeated fewer times in a season than drip irrigation. This meant that there were times when the plant needed moisture but didn’t get it. Taking its solution a step further, Cultyvate’s technology only turns on the drip irrigation when sensors show that a plant needs moisture.
Over a season, the Cultyvate method used 80% less water than flood irrigation — and 35% less water than regular drip irrigation. The real kicker was the yield: 30% greater than with flood irrigation and 18% higher than with regular drip irrigation. This happened because the plant got just what it needed, when it needed it.
Scaling this will be a challenge, because of the upfront costs. A system of carbon credits from methane savings, or indeed a sustainability premium on sugar from such fields, might help scale such efforts and build water resilience.
Country and climate
Most sugarcane fields in India are flood-irrigated. Carefully controlling water usage could increase sugarcane output while reducing water use across India.
“If by scaling these sustainable irrigation practises, we can improve national output by seven to 10 million tonnes over a reasonable period of time, say five years, then you’re talking. You have enough for biofuel dreams,” says Murugappan.
That’s gold in these geopolitically exciting times, when energy self-sufficiency is critical.
Today, political and corporate interest in electric vehicles and biofuels has exploded. Countries are wary about the critical mineral underbelly of electric vehicles, a concern that grew after China restricted shipments of gallium and germanium. This increased the allure of biofuels, which reduce fuel imports, reward farmers and are seen to be greener. What a bargain!
Unsurprisingly, countries feature biofuels front and centre in their Nationally Determined Contributions to reducing greenhouse gas emissions. It’s a way to flaunt green street cred. Brazil and India, the world’s largest sugar producers, both require rising levels of bioethanol to be blended into their petrol. This is only greener if we can reduce bioethanol’s watery underbelly.
A sustainability premium would help balance sugar’s relationship with diet, climate, water and farmer. But, with elections round the corner, don’t hold your breath.
(Mridula Ramesh is a climate-tech investor and author of The Climate Solution and Watershed. She can be reached on [email protected])