Global records are not the only ones going up in flames, as highlighted by Dr Tim Fox, chair of IMechE’s working group on climate change adaptation, in a virtual event yesterday (12 November).
Half the world’s population faced extreme heat for at least 30 days last summer, Dr Fox said, while more than 1,500 records were broken worldwide this June as five continents baked in simultaneous heatwaves. That month was the 13th consecutive month to set a global heat record.
Co-author of “The hot reality: Living in a +50°C world”, Dr Fox set out how extreme heat will change the world, and how we can adapt to it. “When I began this piece of work nearly two years ago, I actually thought it would be quite difficult to convince people that we were going to see the sort of temperatures that I will be talking about in the report. But the last two years have really taken away that barrier,” he said.
Politicians, non-governmental organisations and lobbyists are once again gathered for Cop29 this month in Baku, Azerbaijan, with hopes for meaningful commitments in the fight against climate change. But the current policies being set and implemented around the world “will not really help us” mitigate the new reality of more frequent, prolonged and severe heatwaves, Dr Fox said.
The United Nations Environment Programme’s (UNEP) recent “Emissions Gap Report” said that the world is on track for 2.6-3.1ºC of warming compared to pre-industrial levels by the end of the century, while this week’s WMO report showed that the global average temperature for January-September was already 1.54ºC above pre-industrial levels.
“We can't stop our efforts in mitigation,” Dr Fox said. “We need to double down on those efforts, but we have to accept that we're going to have to undertake some serious adaptation and resilience capacity building to be able to cope with the sort of temperatures we're going to see.”
‘Clean cooling’ could be a critical component of that adaptation. It was a major focus at yesterday’s event, and Dr Fox and colleagues hope the approach could help humans to continue surviving and thriving, even as temperature records tumble.
Facing the heat
Focused on topics including healthcare and the built environment, “The hot reality” sets out the issues that extreme heat will cause, including predicted declines in food production. About 13% of global produce already is lost because of lack of integrity in the supply chain, Dr Fox said, with large amounts of perishable produce not entering a cold chain.
“Whatever we do produce, it's absolutely essential that that makes its way to the marketplace in a safe and nutritious condition,” he said. “The integrity of those supply chains, particularly those that have cooling within them, is going to become increasingly important.”
In the UK, other challenges include 90% of hospital buildings being vulnerable to overheating, and 55% of bedrooms – which would increase to 100% in a 2ºC warmer world, according to Dr Fox.
Worldwide, people in areas that already regularly face extreme heat and other health issues will be put under even more pressure. In Calcutta, India, the summer indoor heat stress index in urban slums has been measured at more than 5ºC higher than outside.
Higher temperatures have widespread implications for human health and mental health, Dr Fox said. “All of this is exacerbated by the urban heat island effect, where the centres of cities have much higher temperatures than the surrounding hinterland,” he said. “Ultimately, this leads to the tragedy of deaths. In the 1991 to 2018 period, 37% of heat-related deaths across 43 countries worldwide could be attributed to climate change-driven temperature rises.”
All of this will put immense pressure on cooling systems, which Dr Fox called to be recognised as critical infrastructure, including a focus on clean cooling. Originally conceptualised at the Centre for Sustainable Cooling, the approach is designed to reduce greenhouse gas emissions while also conserving natural resources, improving air quality, and enabling other sustainable goals.
Achieving such a system will not be easy, however. As temperatures increase, performance of refrigeration systems and air conditioning systems falls. In the UK, refrigeration equipment is typically designed for a maximum temperature of 31-32ºC, Dr Fox added.
“The refrigeration industry, and the engineering community in support of that, has some significant challenges to address increased pressure during these periods of intense heat,” he said.
“We as an engineering community need to understand that it's not just those heatwaves that will have a significant impact. Higher seasonal ambience and increased air moisture-holding capacity has an impact on the performance and reliability of machines over time, through constant operation outside of their optimum design envelopes.”
Keeping cool
Thankfully, there are a wide variety of potential solutions. Cooling for indoor farming and better supply chains could prevent wastage in food production and supply, for example, while a more responsive and targeted approach to vaccine deployment – including better cooling and use of rapid delivery drones – could reduce the 25% of vaccines that are lost due to degradation in the supply chain, particularly in countries that do not have the -20ºC storage facilities for sensitive vaccines.
“We need to see the development of accessible, low-cost, clean cooling technology options and appropriate training programmes,” said Dr Fox.
In construction, we also need to “rediscover” passive methods of cooling, he added – the use of building orientation, shading, reflective materials, green roofs and walls, natural ventilation and internal courtyards to reduce temperatures. “And of course, the same applies for the wider built environment, where natural shading, water bodies, water courses, green spaces and corridors can add to the cooling of urban environments.”
In cases where air conditioners and refrigeration are needed, engineers need to ensure their efficiency is at the highest possible level, he continued, with targets of “mandatory high performance”. There could also be a role for district cooling networks using “waste cold” from industrial processes.
Laying the foundations
Recognising cooling as critical infrastructure must play a critical part in humanity’s adaptation to rising temperatures, Dr Fox said. “If we don't do this… we'll be failing to lay the foundations for a well-adapted, climate-resilient cooling provision for society, creating vulnerability, low national resilience to rising temperatures and more frequent, severe heatwaves, and this will translate into risks to services as vital as food, health, industrial, digital,” he said.
“The stakes could not be higher – but the tangible outcomes and benefits are significant.”
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