Sugar’s not-so-sweet dilemma: the bitter reality of heat stress

On paper, the global sugar industry is enjoying a sweet spot. Worldwide production is increasing year-on-year, nearby sugar futures have bounced back from pandemic lows, and a healthy appetite for biofuels and natural sweeteners is propping up demand.

Yet sugar insiders are far from bullish. Why? Global trade’s dark clouds aren’t helping. Brazil, for example, the world’s largest sugar producer, is bracing itself for possible US-imposed agricultural tariffs. Talk of a US ban on candy and sugary drinks deepen the disquiet.

Away from the headlines, however, the global sugar industry is facing a more pernicious challenge: heat stress. With every year now seemingly the “hottest year on record”, heatwaves and extreme weather events are fast becoming the norm for major sugar producers like Brazil, Thailand, and India.

The threat to sugar is twofold. First, there’s the damage of heat stress to the crop itself. Sugarcane thrives on sunshine, but too much heat impedes photosynthesis, reduces transpiration, and triggers various negative biochemical reactions. The result: a dramatic drop both in plant growth and in sucrose content.

What threats face sugar production? Exacerbating these environmental stresses is the disruption that global heating has on rain patterns. Sugarcane is an especially thirsty plant; just one kilogram of sugar can require anything up 2,500 litres of water. Too much water, on the other hand, and “moisture stress” kicks in.

In short, with longer dry periods and more intense rainfall both on the horizon, sugar finds itself in the eye of an ugly climatic storm.

Threat two relates to those working in the sector. With summer temperatures often soaring above 40°C (104°F) in many sugar-producing countries, worker health is in very real jeopardy. In fact, nearly one third of sugar workers already experience unsafe working conditions, with the number projected to increase along with the rise in global temperatures.

The physiological impacts of heat stress are chilling. Research on sugarcane cutters in Thailand reveals an alarming combination of health complications, from headaches and muscle cramps to dry skin, swelling, and even fever. Separate research in Mexico and Central America adds the risk of kidney dysfunction sometimes resulting in premature death.

Can the bitter reality of heat stress be addressed? In the short term, partially.

How can sugar production be helped?For plant health, steps like improved irrigation, better water management, and crop rotation help blunt the worst effects of today’s changing weather. Drought and flood-resistant varieties also hold out hope. In a similar way, providing water, rest, and shade for workers is a simple yet critical step to protect them from the punishing heat and keep them safe and healthy.

Bonsucro is committed to improving worker safety and food security in the sugarcane sector, one of the world’s largest agricultural industries through certification and its Standard which ensures adherence to strict health and safety standards across the sugarcane supply chain.

But to avoid heat stress turning sugar’s long-term future sour, more needs to be done to tackle the root cause of the problem: namely, harmful emissions being pumped into the atmosphere.

The sugar industry has a critical role to play here; so reducing fertilizer use, fossil fuel combustion, residue burning, and the like. So too must other sectors. If not, the fallout won’t be limited to sugar – it’ll affect us all.