Beating the Heat of Climate Change

August in Europe is typically a period when many businesses close for an extended break due to peak summer temperatures. This year those peaks have arrived earlier and carried on far longer than usual. In July, the mercury rose to 40 degrees (104 degrees Fahrenheit) in the UK, its highest ever temperature, and stayed there for several days. Already, this is the driest summer in 50 years.

While temperatures like these may be familiar to Southern Europe and parts of the US, they caused chaos in a country where few homes or small businesses have air conditioning, and the infrastructure is not designed for withstanding such highs. Train tracks buckled in the heat isolating many commuters, simultaneously wildfires erupted, and sections of a London runway needed to be closed because the tarmac began to melt. As of this writing, the UK government’s environmental agency officially declared a drought in eight out of 14 areas across England, which is projected to last into the new year.

The same impact was felt in France, Germany, and Spain. In multiple countries river flow is severely affected, with stored water volumes depleted. It is tempting to dismiss extreme heatwaves as a one-off seasonal phenomenon. After all, heatwaves have happened before in history with minimal consequences. But what we are seeing now in rate and regularity is undeniably a result of climate change.

The number of days with extreme heat doubled between 1960 and 2020, becoming more frequent and lasting longer. For those years of extreme heat, an annual loss of between 0.3% to 0.5% of the GDP is estimated, and if current projections are anything to go by, that figure will rise to 3.5% of the GDP by 2060.

Cities Take the Heat

Of all places, cities are the most vulnerable to climate change, with temperatures tending to run several degrees higher during heatwaves than in the surrounding countryside. This is because of the urban heat island effect created by the impact of large quantities of dark-hued, human-made surfaces (think roads, sidewalks, and buildings) that tend to absorb sunlight and trap heat. Cities experience average summer temperature rises of between 1.9 degrees Celsius and 4.4 degrees Celsius. Risks do not necessarily diminish when summer passes, as higher global temperatures cause wetter weather, with sea levels rising along coastal cities. Extreme weather is felt more acutely in urban areas. Built on concrete, they absorb solar radiation but not water, increasing the effects of heatwaves and the likelihood of severe flooding from heavy rains.

Currently over 56% of humanity is crowded together in cities, and it is projected that seven of 10 people will be urban dwellers by 2050, so adapting to scarce resources may require extraordinary water and energy management measures in affected countries.

As city density grows so does the need for newly constructed buildings for living and working that are energy efficient. However, in places like the UK, 80% of existing buildings will still be around by 2050 and many long after that. So, programs like the UKGBC Whole Life Carbon Roadmap targets the rapid decarbonization of existing buildings. Making the places where we live and work cool and comfortable in the future whatever the weather, while reducing the burden on the power grid and limiting the emission of CO2 into the atmosphere, is critical.

Economic and Individual Risks

High temperatures can be deadly as bright sunlight often leads to higher levels of air pollution, placing the most vulnerable, for instance children, the elderly and those with underlying health conditions, at risk for respiratory illness. Those deaths are more acute in developing countries with scarce resources to adapt and mitigate the effects of a changing climate.

Something familiar to all UK office workers over the past month is the impact of heat on work performance. Sweltering offices make workers on average 20% less productive, which has direct economic implications.

Over the past 30 years globally, there has been a steady rise of air conditioner use accounting for nearly 20% of the total electricity used today in buildings around the world. Space cooling puts enormous strain on electricity systems in many countries, while driving up emissions and increasing risks of summer blackouts due to power load as homes and offices try to maintain a comfortable room temperature. Air conditioning use is set to triple by 2050 as developing countries become more prosperous.

Although one heatwave effect is the absence of water, global warming has ramifications for changes in rainfall patterns during the year, and extreme events like storms and floods may cause contamination of water and food supplies. This also increases the risk of water and vector or mosquito-borne contagious diseases.

Mitigation Through Future Proofing Buildings

So, what mitigation measures are currently being explored?

On a national level in the US, as part of the Bipartisan Infrastructure Deal in 2021, the government is investing over $50 billion to protect against droughts, heat, and floods. Alongside this, the recent approval of the Inflation Reduction Act includes huge incentives to ramp up carbon-capture facilities, urge green hydrogen production, and boost US manufacturing of solar panels, wind turbines, and next-generation batteries.

Across the EU, the European Green Deal is a key initiative to drive energy efficiency in the building sector. Through initiatives like the Renovation Wave, the EU is taking aim at Europe’s older building stock of more than 220 million building units, most built before the 21^st century. The quantity of older building stock, 90% of which will still be standing by 2050, is even greater than in the UK. Making these existing buildings sustainable, which for the most part are not energy efficient and still rely on fossil fuels for heating and cooling, represents a major challenge but also an opportunity. City planning authorities and urban planners in cities across Europe and the US are beginning to make use of high-resolution heat maps to improve urban planning and protect citizen’s health as well as cultural heritage.

More recently, we have also seen the rise of the Urban Heat Officer in cities as diverse as Miami in the US, Athens in Greece, and Freetown in Sierra Leone. Their role is to address rising temperatures driven by climate change through increasing awareness of extreme heat risks, planning, and coordination of long-term-risk-reduction projects. There is no priority more important than the building sector, where GHG emissions from building operations (energy used to heat, cool, and light buildings) account for 28% of the global total.

One of the major considerations for commercial building owners right now is how to create work environments where users can be productive and kept cool and safe while effectively managing water and energy use to lower the burden of the heat-island effect. Already, changes to building regulations are forcing developers to rethink building design to prevent overheating. This same thinking needs to be adopted for existing buildings that are not currently energy efficient. Many UK building regulations now take account of ventilation and overheating as well as energy efficiency.

To do this effectively instead of just removing excess heat from our city buildings, we will need to prevent the sun’s rays from creating the problem in the first place through mitigation measures. Then, to reduce climate risks and strengthen the resilience of buildings, we have to create adaptation measures.

Mitigation Applied to Buildings

Mitigation measures aimed at reducing GHG emissions include promoting energy saving initiatives through a combination of high-tech and natural measures. For buildings this means switching energy sources from fossil fuels to renewable energy sources (wind and solar). This does not mean simply changing energy suppliers but considering how the building fabric can generate much of its own power by covering heat absorbing surfaces (particularly rooftops) with solar panels that reduce heat gain within the building as well as pressure on the local energy grid.

Where rooftops or balconies are accessible, the integration of vegetation to building projects (such as green walls, terrace and roof-top plantings) not only provides passive cooling methods but also creates welcoming spaces to support employee wellbeing. In addition, glazed surfaces will need tinted glass or blinds or shutters to keep out sunlight. New and retrofitted old buildings will have to be designed to increase ventilation with natural flows of air that keep internal temperatures down and reduce reliance on energy-intensive air conditioning.

To encourage better air quality for workers, building owners can also incorporate features that facilitate the use of non-motorized transport. The installation of parking lots for bicycles and charging stations for electric vehicles reduces the CO2 burden from vehicles.

Designers will have to comprehensively consider all facilities in terms of architectural concept, understanding how to adapt existing buildings as well as new structures.

Adaptation Applied to Buildings

Adaptation measures involve adjustments to the actual experience of climate change from sea-level rise to more intense extreme weather events. Existing buildings are especially vulnerable because the environmental conditions they were built to withstand have changed, impacting the structural features of the buildings as well as indoor conditions.

An inability to regulate indoor temperature not only creates thermal discomfort for users but negatively affects their health, wellbeing, and productivity. Ventilation systems that rely on passive cooling and heating are of fundamental importance. Buildings with passive design measures will be more comfortable and resilient during power outages. Incorporating building efficiency measures that reduce energy dependence on heating/cooling/electrical services that are prone to failure in extreme events will be of equal importance. Integrating energy storage and micro grids on site will increase energy resiliency during power outages. Having an intelligent building management system to control building blinds and shutters that automatically adjust to the sun’s position during warmer periods of the day and make allowances for seasonal changes will ensure comfortable temperatures all year round.

Likewise, water conservation will require strategies that promote efficient water use, reduction, and water treatment—the installation of systems to collect and treat grey or black water for use, for example, water from irrigation or toilets, as well as the introduction of double-flush toilets and low-flow taps and showers for kitchens and bathrooms.

Planning around potential flooding is equally important for businesses because sensitive operations can be disrupted by extreme weather events. Building in flood zones will require a raised floor level and a ban on basements to prevent flood water entering the building. Companies can prevent the kind of shutdowns that impact sensitive information by locating IT rooms and data centers away from lower-level areas.

An integrated energy efficiency strategy will need designers to include robust and resistant materials choices in building standards, especially for those materials such as metals, glass, and tiles that are carbon-intensive when newly manufactured. Practical mitigation options for the building sector include utilizing carbon sink as well as low-carbon materials and products in buildings, such as low-carbon bricks, green concrete, and recycled-content materials for internal and external flooring and cladding,

Conclusion

Ninety percent of our time is spent indoors, so ensuring our buildings offer protection against increasingly extreme weather as a result of climate change requires we adapt them to suit the evolving needs of occupants. This is one of the most important measures that architects, designers, and construction professionals can take in combatting this crisis. Drawing on our passion and ingenuity to apply construction knowledge supported by rapidly advancing technology is the best use of our skills to achieve net zero and quell global warming, ensuring our planet’s robust future.