Continuing our Designing for Disaster series, disasters expert Ilan Kelman shares advice for designers and architects on averting catastrophe.

A generation ago, in 1999, a team led by disasterologist Dennis Mileti published a comprehensive review of disasters in the US titled "Disasters by Design". The key lesson for design professionals, based on decades of previous disaster science, was that disasters can be stopped through planning, engineering and architecture connected to other skills and professions. The choice has to be made to do so.

Choices are made, through policies, laws, client expectations, tender details and budgeting, among other constraints. How and where to site buildings, which materials to use and which design standards to follow.

Admit the limits and plan for what happens when (not if) those limits are surpassed

These choices determine how well infrastructure performs under pressure. Roofs could be designed and built to withstand the strongest winds possible, such as a powerful tornado passing over. It would be expensive and might increase problems in earthquakes, during which heavy roofs can increase collapse potential. Not to mention considering strikes from tornado-borne debris.

Alternatively, laws could require that wind, earthquakes, landslides, avalanches, tsunamis, volcanic ash and all other environmental hazards plus debris are accounted for. Many require similar design features, rather than trade-offs. The correct strength and slope of roofs can address wind, snow, and volcanic ash. Wall, door and window design for lateral forces helps with wind, floodwater and debris.

Irrespective, few structures could withstand everything from nature, and those might not be comfortable to use. Instead, understandable choices are made to balance different needs.

Admit the limits and plan for what happens when (not if) those limits are surpassed. As long as plenty of warning is available alongside safe and effective evacuation routes and sheltering for everyone, it is often best to get out of the way of a fire or a flood followed by rebuilding afterwards. Then, authorities and people affected must be committed to and certain of warning, evacuation, sheltering and reconstruction support for everyone.

The disaster is not a fire, a flood or wind, since sometimes people suffer during these hazards and sometimes they do not. The disaster is when infrastructure collapses lead to suffering, when people die during evacuation or sheltering, or when support for sheltering and reconstruction is absent, so again people suffer. The disaster is people suffering, rather than how buildings are affected by nature.

Disasters are caused by longer-term societal decisions taken with and without design professionals to avoid preparing for, mitigating damage from, reducing risk of and planning for environmental phenomena. The disaster is from society, not nature.

The disaster is people suffering, rather than how buildings are affected by nature

To convey this message and to confer responsibility for disasters on those with the power and resources to stop them, it is best to avoid the phrase "natural disaster". Disasters are not natural.

So what to do about the changing environment due to human-caused climate change? For tornadoes, the verdict remains undecided on how they are affected. Meanwhile, human-caused climate change appears to be leading to fewer hurricanes, but those which form are much more intense, meaning stronger winds and much more rainfall.

Designing for fewer hurricanes under human-caused climate change does not make sense, since a hurricane can and still will hit in hurricane alley during hurricane season. Considering more intense hurricanes is important for design, although it would have been necessary even without human-caused climate change, since floodplains and wind are affected by local decisions such as river engineering and high-rise development.

In fact, a strong hurricane could hit any year in any hurricane-prone location. The climate has long been changing, even without human influence, including several decades-long cycles leading hurricane numbers to wax and wane. Now, we are changing the climate quickly and substantially, far beyond the experience of modern humanity, with the effects all around us and visible now.

One enormous, frightening change that is impacting infrastructure and killing people every summer is heatwaves which are longer and more intense than we have experienced previously.

The signal from human-caused climate change is clear in heat-humidity values exceeding the human ability to survive outdoors, from India and Pakistan to London and Paris to British Columbia and Washington state. We can attribute many heatwave deaths to human-caused climate change, especially when it does not cool down sufficiently over successive nights and then our bodies do not recover from the day's heat.

We are caught in wider societal systems and expectations forcing choices that can lead to disasters

Twenty-four-seven indoor cooling is one approach. It is expensive, it burdens the power grid leading to power outages, and not everyone can stay indoors during a heatwave. Jobs are particularly affected in agriculture, construction, and delivery. Indoor garment workers in South Asia are also feeling the impacts, since their workplaces are typically crowded with poor ventilation. Implementing designs to help all these sectors under expected heat-humidity combinations is challenging.

Instead, stopping human-caused climate change would be the most successful choice for avoiding heatwave disasters. Laws and policies could require infrastructure to incorporate energy use reduction while switching to local and renewable energy supplies.

Wider planning aspects would support walking, cycling, and public transportation, factoring in safety, reliability, and all weather. These points then circle back to avoiding disasters in any weather – including the terrifying heatwaves happening now and certain to get worse due to human-caused climate change.

Design professionals can make choices to prove that disasters are not natural. More often, we are caught in wider societal systems and expectations forcing choices that can lead to disasters.

It is particularly challenging to address all concerns together. Imagine designing and building a school which is self-sufficient in energy and water while being outside an expanding floodplain – perfect for climate change, yet it then collapses in the next earthquake. Or building an entirely disaster-resistant school, accounting for all climate-change impacts, in a country where girls are not permitted to attend.

"Disasters by Design" refers not only to infrastructure damage during weather and other environmental phenomena. It also refers to long-term societal decisions forcing people into circumstances that cause problems for their everyday living.

Ilan Kelman is a professor of disasters and health at University College London's Institute for Risk and Disaster Reduction and is the author of multiple books on the subject of disasters, including Disaster by Choice.

The image is courtesy of the National Oceanic and Atmospheric Administration via Unsplash.

Designing for Disaster

This article is part of Dezeen's Designing for Disaster series, which explores the ways that design can help prevent, mitigate and recover from natural hazards as climate change makes extreme weather events increasingly common.