How to be cool: the next frontier of climate change mitigation

With pandemic measures largely restricting me to my apartment in hot and humid Taipei these last months, and currently waiting for typhoon In-Fa to make landfall, I have come to appreciate, or perhaps better said dread, the impacts of a heating planet.

The expected rise in frequency and intensity of extreme weather events will increasingly affect harvests and food prices in an overpopulated world, kill biodiversity in fragile but essential coral reefs, disrupt industrial supply chains and threaten homes and livelihoods, not only in the poorer parts of the world, but as recently seen also in ‘safe’ rich geographies like Germany and the US.

What is less spoken of are the devastating reinforcing feedback loops that global warming is triggering, from colossal amounts of methane greenhouse gas escaping from defrosting permafrost in high latitude arctic tundras, to a feedback loop literally happening closer to home: the increased need to cool ourselves.

Singapore’s founding father Lee Kuan Yew famously hailed air-conditioning as one of the enablers of his country’s productivity revolution. Preserving food and vaccines is hard to imagine without cooling and on a warming planet cooling is becoming increasingly crucial in combating heat related mortality, not only from direct impact on health, but also indirect, such as a higher incidence of violent crime during heat waves.

The IEA expects the number of air conditioning units worldwide to grow from 1 billion today to 6 billion by 2050. Unless radical efficiency gains are made, this would result in air conditioning consuming about 13% of all electricity worldwide (as much as all of India and China today) and producing 2 bn tonnes of CO2 per year. Not only would this contribute over 0.5 degrees Celsius of global warming by the end of the century, it already is a major factor in the heat-island effect currently observed in cities.

Staying cool without wrecking the planet further will require radically accelerating the transition to renewable energy sources. It will also require ‘smarter’ power grids to deal with more extreme peak energy demand, as increased AC use during heatwaves can cause peak power demands of 30%-50% above regular demand, already forcing power utilities to cut power supply or face wider blackouts.

But some of the highest payoffs will come from reinvention of the by now century-old AC technology, as RMI and the government of India (one of the geographies with highest expected growth in AC units) are trying to incentivise through the Global Cooling Prize. Promising innovations are happening, from technologies using radiative cooling such as SkyCool Systems, to the membrane and water-based cooling technology being developed by Singapore’s NUS, but investment in innovative cooling solutions (USD 350m in 2019) is still surprisingly underweighted compared to other energy transition technologies.

The bigger the challenge, the more we need to think in systems. For a massive challenge like cooling ourselves on a warming planet (1.1 bn people still lack access to cooling), learning and collaborating across sectors allows us to realise that the best cooling is the one we avoid. Passive design can play an important role here, for example improving wind flow through city design or covering buildings with ‘cool roofs’ of heat reflective colours or self-shading facades, such as explored by Foster & Partners, incorporating low carbon aluminium by producers such as Norsk Hydro. Singapore is arguably one of the most ambitious cities when it comes to system planning, deploying a ‘digital urban climate twin’ that allows it to evaluate numerous city system design scenarios. 

But the next frontier to explore might be working with nature as our teacher and ally. Nature based solutions in cities have the potential to mitigate long term climate change, support biodiversity, improve air quality and water management, boost liveability of cities and wellbeing of citizens, and reduce costs. Medellin created 30 green corridors across the city, reducing the temperature by more than 2 degrees Celsius. Milan is planning to plant 3 million trees by 2050 and green roofs in cities such as Athens and Vienna have shown to reduce energy use by up to 15% and hugely reduce peak loads.

Cities have become the perfect platform for visionary actors to join forces across stakeholders to identify and pilot nature-based systemic solutions to mitigate climate change.

What’s cooler than that?  




As first published on LinkedIn.