As the number and intensity of storms increases, Dr Liz Marlow of Cundall considers how we might become better prepared
Last month, yet another named storm, Darragh, swept across the UK, bringing peak wind gusts of 96mph and heavy rain. It is becoming more common for named storms to dominate the news headlines, particularly due to their magnitudes and their impact on communities.
With damage to roads, bridges, railway lines, property, power and water supplies caused by fallen trees and flying debris, together with the equivalent of a month’s rainfall in 48 hours leading to flash flooding, the disruption can be significant, as can the devastation caused to property and farming land.
So we must ask ourselves, if climate change is increasing the number of storms and their intensities, how much should we keep investing in insurance, rather than helping communities to become more resilient?
Firstly, we should draw a distinction between natural hazards and climate change. Natural hazards, as the name suggests, are natural. These include hurricanes, tsunamis, volcanic eruptions and, of course, floods.
Their intensities, however, are worsened by the effects of climate change. When a natural hazard is discussed within a context of climate change, it is the impact of climate change that generates uncertainty and leads to discussions about the probability of such events and the need for scenario planning.
Moving on to “resilience”, this term has multiple interpretations, but essentially it is about coping and preparing for a natural or social hazard. That is, a hindrance to a community’s access to essential resources like food, water and health service. We need to prepare for disruption and understand that climate change exacerbates some of these issues leading to more extreme and damaging consequences.
We must ask about the engineer’s role in designing for resilience and what the impact of climate change is on design codes
The United Nations Office for Disaster Risk Reduction defines resilience as “the ability of a system, community or society exposed to hazards to resist, absorb, accommodate, adapt to, transform and recover from the effects of a hazard in a timely and efficient manner, including through the preservation and restoration of its essential basic structures and functions through risk management”.
At this point, we must ask about the engineer’s role in designing for resilience and what the impact of climate change is on design codes. Are the current safety factors enough? And what does it mean for a building to be prepared and climate resilient?
Focusing on the hazard, according to CMIP6 model projections by the intergovernmental panel on climate change (IPCC), the wind gusts of future storms are likely to increase as the climate changes. While this might only be a minimal increase in a global context, the potential damage at a local level is massive.
While buildings and bridges are designed for wind codes, intense rainfalls bring the possibility of flood risk and surface water drainage issues. This exacerbates the issues of considering a community’s resilience to cope with no power or mains water – and this overall disruption is not a mandatory thought.
>> Also read: UK’s environmental adaptation strategy falls far short, says climate change committee
>> Also read: We still aren’t moving fast enough in the race against climate change
We have a problem of designing in isolation without considering local community needs and potential impacts. This must change.
Last year, my local community had no water supply for a week and had to go to the local carpark to obtain the emergency ration of water for drinking, cooking and washing. When multiple systems fail, communication with your community is essential, as is access to emergency systems such as hospitals and healthcare. In the UK, we have local resilience forums, but there is a need for communities to be made aware of their existence (local resilience forums: contact details - GOV.UK).
Our communities need to be better prepared as well as resilient and perhaps follow the example of the city of New York. Having experienced devastating weather events such as hurricanes Irene and Sandy, the New York City panel on climate change was set up as an independent advisory body to conduct research and analyse climate change data and advise local policymakers on resilience and adaptation strategies to protect against climate change-related hazards. As a result, with changes to their legislative processes, the city’s ability to cope with hazard events has dramatically improved.
It is simply no longer enough to just to tick the boxes of design codes and not account for climate risks over time
As windstorm intensities are uncertain and wind gusts increasing, along with intensity of rainfall, designers and constructors will need to adapt for they interact with land use change over time. Ultimately, design responsibility should be with engineers because of the multiple factors at play, particularly now in the UK with the Building Safety Act.
Having the insight of both climate science and responses, I ask myself serious questions about how engineers should prepare for the future and consider the “adaptation gap” of design codes and engineering knowledge in practice, as not all codes are climate risk informed. Is it enough to be just using generic uplifts for design parameters for one-in-a-hundred-years storms? Or do we need to be basing our design on actual climate science and modelling?
We require action on multiple levels to fast-track better decision-making and raise awareness that design codes also need reviewing to cope with tomorrow’s long-term problems.
It is simply no longer enough to just to tick the boxes of design codes and not account for climate risks over time. We should be designing for the here and now, according to the latest science and data, rather than looking retrospectively.
So, I ask those responsible for design, which scenarios and relevant design codes will you design according to? And, when complete, will it be part of a climate-resilient community?
No comments yet