Cooling is essential to preserve food and medicine. It underpins data, industry and economic growth, is key to sustainable urbanisation and provides a ladder out of rural poverty. With temperatures rising, it increasingly makes much of the world bearable, or even safe to live in.

In developing countries, billions of people live without cooling and suffer the consequences daily. The lack of adequate cold storage and refrigerated transport causes 2 million vaccine-preventable deaths each year, and the loss of 200 million tonnes of food. There is no question that we will need far more cooling and by 2050 there could be more than 9.5 billion cooling appliances worldwide – more than 2.5 times today’s ~3.6 billion (Global Cooling Initiative).

Cooling is, however, energy intensive. We are seeing the development of more efficient cooling technologies. But even allowing for these, with projected growth in demand, the cooling sector will increase its overall energy consumption by 2050 by 90 per cent to ~7,500TWhs annually compared with 2017 levels (3,900TWhs).

Without decarbonising electricity production, this would result in an additional ~2.5GigaTonnes (GT) of CO2e annually, bringing the total C02e from cooling to more than 6GT. This is 40 per cent of the world’s total target for direct CO2e emissions for 2050 (13GT) if we are to hold temperature increases to 2°C. Decarbonising just the new projected cooling growth would require 3,000GWs of new installation; 75 per cent of the IEA’s projections for the global cumulative installed PV capacity by 2050.

Put simply, we have a problem.

This, however, is only half the picture. Under these projections, much of the world would still only have low penetration levels of cooling. We would still have high levels of food loss. With more of the world experiencing life-threatening temperatures and no cooling, and medicines and vaccines spoiled in the supply chain, we will not see the reductions in mortality nor the social advancement and economic growth that all we aspire to through the UN Sustainable Development Goals. If anything, combined with the impacts of climate change, impacts of a lack of cooling will get worse.

If we are to sustainably deliver cooling for all, we must stop thinking that green electricity and technology efficiency can meet the demand alone. We need step-change solutions; new system-level approaches that re-imagine the way we deliver cooling: recognising the thermal, waste and wrong-time energy resources available for cooling and accelerating to market the novel energy vectors, thermal stores and clean cooling technologies that can harness them.

The barrier is that when people talk about energy, they normally mean electricity, and when they talk about energy storage, they mean batteries. We need to change the question. Not ‘how much green electricity do I need to generate?’ But rather ‘what is the service we require, and how can we provide it in the most economic and fit for market way within the confines of our natural resources?’

Thinking thermally, not just electrically, is a big step-change; but without it, we are sitting on a carbon time-bomb. The challenge is how to embed this approach quickly enough to avoid investment in conventional equipment that locks in cooling emissions for years or decades.

One concern is that investment into cooling research in the EU/UK is less than 0.22 per cent of our engineering research budget. Globally, despite the widespread need for sustainable, affordable cooling, only 0.1 per cent of Overseas Development Assistance is spent on cooling.

Economic and social development and the environment have to live together; we can no longer have one at the expense of the other. Rather, our aim has to be a world where everyone can live well and within the sustainable limits of our planet. Clean cooling sits at the nexus of this challenge; not just clean electricity. And, with much of the demand for cooling increasing over the next decade, time is not on our side.