Here is what will happen to most buildings as global warming accelerates

After the event has passed, the damage can be repaired and additional measures can reduce the risk of it happening again. But climate change will breed conditions where these parameters are exceeded more often and to a far greater degree. Some changes, such as higher average air temperatures and humidity, will become permanent. What were previously considered once-in-a-century floods may become a regular occurrence.

Some of these impacts are fairly obvious. Houses will be more prone to overheating, putting the lives of residents at risk. Flooding will happen more often and inundate greater areas, to the magnitude that some places might have to be abandoned. The village of Fairbourne in Wales has already been identified as a likely candidate. Failure to act on both of these threats in the UK was highlighted in a recent report by the Climate Change Committee.

To some extent, these impacts will be localised and containable, with fairly simple remedies. For example, overheating can be reduced by shading windows with awnings or blinds, good insulation, and ample ventilation. Perhaps more worrying are the insidious effects of climate change which gradually undermine the core functions of a building in less obvious ways.

Termites and melting asphalt

More intense wind and rain will cause external cladding to deteriorate faster and leak more often. Higher temperatures will expand the regions where some insects can live. That includes timber-eating termites that can cause major structural damage or malaria-carrying mosquitoes, from which living spaces must be redesigned to protect us.

Materials expand as they get hotter, especially metals, which can cause them to buckle once their designed tolerance is exceeded. For one skyscraper in Shenzhen, China, high temperatures were partially blamed for causing the structure to shake, forcing its evacuation, as the steel frame stretched in the heat. Extreme temperatures can even cause materials to melt, resulting in roads “bleeding” as the surface layer of bitumen softens.

Subsidence

Subsidence, a term referring to when the ground below a structure gives way, causing it to crack or collapse, is also expected to happen more often in a warmer world. Buildings with foundations in clay soils are particularly vulnerable, as the soils swell when they absorb water, then harden and shrink as they dry out. Changing rainfall patterns will exacerbate this.

Hence, extreme wind-driven rain events will be more prevalent in the future. As such, the exterior of the building will be subjected to more intense climate loads of longer duration that will, in turn, increase the risk of premature degradation of building elements, such as roof, wall and fenestration systems, and as well, as the risk of water entry of building elements, resulting in moisture-related problems.

An increase in global temperatures will cause a decrease in heating loads, as evidenced by reductions in heating degree days, and an increase in cooling loads, in particular in urban agglomerations where heat island effects may prevail over the hotter months.

 Lack of attention to extreme heat events may bring about overheating in buildings that, in turn, increase health risks to the vulnerable portion of the population such as the elderly, the sick and physically challenged, and the very young.

Concrete cancer

Perhaps the biggest concern is how climate change will affect reinforced concrete, one of Earth’s most widely used materials. Used in everything from skyscrapers and bridges to the lintels above windows in homes, reinforced concrete is made by placing steel rods within a mould and pouring wet concrete in. Once dry, this makes structures incredibly strong.

But a warmer, wetter climate will play havoc with the durability of this material. When the steel inside the concrete gets wet it rusts and expands, cracking the concrete and weakening the structure in a process sometimes referred to as “concrete cancer”.

Buildings in coastal areas are especially susceptible as the chloride in salt water accelerates rusting. Rising sea levels will raise the water table and make it saltier, affecting building foundations, while salt-spray will spread further on stronger winds.

At the same time, the concrete is affected by carbonation, a process where carbon dioxide from the air reacts with the cement to form a different chemical element, calcium carbonate. This lowers the pH of the concrete, making the steel even more prone to corrosion. Since the 1950s, global carbon dioxide levels have increased from around 300 parts per million in the atmosphere to more than 400. More carbon dioxide means more carbonation.

Carbon dioxide concentrations are rising mostly because of the fossil fuels that people burn for energy. Fossil fuels such as coal and oil contain carbon that plants pulled out of the atmosphere through photosynthesis over millions of years; we are returning that carbon to the atmosphere in just a few hundred.

Since the middle of the 20th century, annual emissions from burning fossil fuels have increased every decade, from nearly 11 billion tonnes of carbon dioxide per year in the 1960s to an estimated 36.6 billion tons in 2023 according to the Global Carbon Budget 2023.

Carbon cycle experts estimate that natural “sinks” or processes that remove carbon from the atmosphere, on land and in the ocean absorbed the equivalent of about half of the carbon dioxide we emitted each year in the 2011-2020 decade. The total amount of carbon dioxide in the atmosphere increases annually because we put more carbon dioxide into the atmosphere than natural sinks can remove.

The more we overshoot what natural processes can remove in a given year, the faster the atmospheric concentration of carbon dioxide rises. The annual rate of increase in atmospheric carbon dioxide over the past 60 years is about 100 times faster than previous natural increases, such as those that occurred at the end of the last ice age 11,000-17,000 years ago.

Climate change is indiscriminate

The tragic recent collapse of an apartment building in Miami in the US may be an early warning of this process gaining speed. While the exact cause of the collapse is still being investigated, some experts suggest it might be linked to climate change. Whether or not the link to climate change proves to be true, the event was a wake-up call, highlighting the fragility of our buildings.

 It should also be seen as a clear demonstration of a critical point; wealth does not protect against the effects of climate cannot stop them at the border. Climate change is indiscriminate. Buildings are vulnerable to these impacts no matter where in the world they are, and if anything, the modern buildings of developed countries have more things in them that can go wrong than simpler traditional structures.

Other climate problems are impossible to segregate to just poorer communities. Northern California’s air was rated the worst in the world from all the smoke. One might be able to buy a mask or an expensive home filter to compensate, not only are those technologies not 100 percent effective, but they are also an inescapable degradation of the quality of life. Nobody would choose walking around under a blood-red ashen sky with a respirator or staying inside a hermetically sealed house changing the air filter every few hours, over great lungfuls of clean air and blue skies.

What can be done?

The only option is to begin adapting buildings to meet the changing parameters in which they are operating. The sooner we begin retrofitting existing buildings and constructing new ones that can withstand climate change, the better.

Jabulani Sikhakhane recommends adapting designs inspired by nature. An emerging approach to urban design, ecomimicry, recognises the many lessons we can learn from the self-organising systems of the natural world. In the words of designer Van Day Truex, when it comes to design, Mother Nature is our best teacher. A

n ecomimicry approach starts with reading the local landscape like a book. By getting to know how different parts of a regional ecosystem intertwine, urban designers can integrate the ecological functionality that already exists in the landscape, such as an abundance of pollinators, natural flood defences and food, into what they build.

Examples include covering roofs in locally typical vegetation that can feed animals and humans, or building around, not over, coastal treasures such as dunes and mangrove forests, and incorporating habitat features of these landscapes into the new surrounding landscaping to increase habitat connectivity, ecosystem service provision and resilience.

With an awareness of nature’s importance gaining momentum, increasing numbers of entrepreneurs are developing nature-based designs with ecomimicry at their core. Welcoming biodiversity back into our urban areas can reconnect communities with nature, supporting equal access to the social, physical and psychological benefits nature provides us for free.

If ecomimicry is to gain a foothold in our landscapes, three things are necessary: We must involve local ecologists who understand the unique complexities of the habitats being altered. We must ensure that the inherent value of all creatures is reflected in our approach to urban design. And we must embed this approach into policy, so it lasts for years to come.

Carbon cycle

Since the middle of the 20th century, annual emissions from burning fossil fuels have increased every decade, from nearly 11 billion tonnes of carbon dioxide per year in the 1960s to an estimated 36.6 billion tons in 2023 according to the Global Carbon Budget 2023.

Carbon cycle experts estimate that natural “sinks” or processes that remove carbon from the atmosphere, on land and in the ocean absorbed the equivalent of about half of the carbon dioxide we emitted each year in the 2011-2020 decade. The total amount of carbon dioxide in the atmosphere increases annually because we put more carbon dioxide into the atmosphere than natural sinks can remove.

This article was first published by theconversation.com