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Natural Environment

Resilient urban design for climate risk mitigation

Urban climate adaptation isn't just about finding new solutions for new problems. In many cities, the biggest threat posed by planetary warming is the exacerbation of age-old risks and inequities.

World Built Environment Forum
9 June 2021

Historically climate-stressed cities are most vulnerable to intensifying weather patterns…

Or, put more simply, areas that have long been prone to flooding are more likely to experience flooding events than ever before. Drought afflicted regions, meanwhile, are becoming increasingly parched.

“The extremes are pretty amazing,” says Rob Blevins, Founder and Senior Meteorologist with METCON. “Manaus, on the Amazon River, recently set an all-time record for high flow and now there’s flooding across the city. At the same time, in Southern Brazil they’re suffering from power shortages caused by drought. Weather patterns are becoming more extreme, and you don’t have to look very hard to see it.”

The underlying cause of intensifying climate patterns is oceanic warming. Crystal Egger, President of Monarch Weather Consulting, explains: “When ocean waters warm, you see more evaporation – about 7% more water in the atmosphere. That’s going to lead to a higher incidence of precipitation events. There are forecasts showing that we can expect 20% more rainfall during storms. In some places, one-in-100-year floods are becoming one-in-10-year events. And then our dry regions are becoming dryer, suffering longer periods of drought and heat waves. The science is telling us that planetary warming will continue, so we’ll see further rises in global climate hazards.”    

When ocean waters warm, you see more evaporation – about 7% more water in the atmosphere. That’s going to lead to a higher incidence of precipitation events. In some places, one-in-100-year floods are becoming one-in-10-year events.

Crystal Egger
President, Monarch Weather Consulting

As the climate emergency unfolds, new cities are regularly added to risk lists. Nonetheless, those cities in need of the most urgent interventions tend to be those that have long been especially vulnerable to climate-related disaster. The floodwater threat is not new to places like Rotterdam, Miami and Osaka. But the urgency with which city leaders must act is ratcheting up. None can say they have not been warned.

…and the climate emergency is deepening existing social fault lines too

To frame climate change as an environmental emergency is to paint only a partial picture. In the urban context, existing social inequities are likely to widen without effective policy responses.

Resilient urban design for climate risk mitigation

Rising sea levels and climate related extreme weather events pose an existential risk to some of the world’s most economically and strategically important cities. How does the risk profile of natural hazards change from region to region, and where are the dangers most pronounced? What can policymakers, businesses and built environment professionals do to future-proof urban centres accordingly?

Proximity to water has long been considered a desirable feature for homes and workplaces, with high-price developments often springing up on seafronts and riverbanks. Locational premiums attached to such properties make them attractive to developers and a certain category of buyer alike. But the effects of rising sea waters threaten the viability of these projects and the security of their residents. Any mass retreat to higher ground could have complex knock on effects for less-advantaged communities. This is how David Baxter, CEO of Mitig8 Risk Management, introduces the phenomenon of “climate gentrification.”

He says: “Buildings in coastal areas are suffering the effects of rising sea levels, so developers have started looking inland. Land that is six or seven feet above sea level is better protected. But these are often the locations where poorer communities and working-class populations reside. As these areas gentrify, those people get pushed out.”

Of course, people cannot be forced to remain in at-risk areas. But inclusive urban regeneration requires developers to perform a notoriously difficult balancing act, even without the further complication of climate adaptation concerns. High-profile activist groups such as Extinction Rebellion and Black Lives Matter have been keen to underline the ethnic and socio-economic dimensions of the climate crisis. The onus will be on planners and policy makers to manage these sensitivities if they wish to avoid creating new grievances in these already-divided times.

Land that is six or seven feet above sea level is better protected from rising sea levels. But these are the locations where poorer communities and working-class populations currently reside. As these areas gentrify, those people get pushed out.

David Baxter
CEO, Mitig8 Risk Management

Unseasonal weather is bad for seasonal produce

The link between livestock farming and greenhouse gas emissions is well-explored. Many have accordingly revised their dietary habits, turning to veganism, vegetarianism, flexitarianism and pescatarianism. Though such options are clearly less carbon intensive, meat-free or restricted diets are not necessarily an uncomplicated “good thing” in climate terms. The average lettuce travels over 2000 miles to make it on to the American plate. And, unsurprisingly, the agricultural supply chain is threatened by numerous facets of the climate crisis, not least among them shifting seasonal norms.

“Spring is getting warmer,” warns Rob Blevins. “That’s causing fruit crops to bloom early. Japan just had its earliest ever cherry blossom. But the cold air is still around, and these sorts of crops – apples, peaches – are vulnerable to that. You see whole regions losing their entire fruit crop overnight.”  

One potential solution to this problem could be vertical farming – a currently imperfect but nonetheless intriguing proposal. Vertical farms are more resilient to unseasonal climate patterns such as long winters and wet summers. Furthermore, they can be situated in densely populated urban areas, reducing farm to plate distances and associated carbon footprints. They can also revive seemingly obsolete industrial real estate and stimulate local economies through jobs creation. They are, though, energy intensive and lack a proven business model. Any cities able to iron out these wrinkles could enjoy handsome dividends.