How does a wetland cope with change? When extra high water flows into a wetland, the plants can withstand it – resist it – as long as the high water isn’t too deep or repeat too often to affect the established plant community. But if the water starts coming in more often or at different levels than before then the wetland community begins to adapt. Species that prefer higher or lower water levels begin to assert their dominance as the makeup of the wetland species adapt to the frequency or magnitude of changes in water levels. But if the water comes in and never leaves, then it may no longer be a wetland – it may be transformed into a lake. Wetland communities resist change within certain thresholds, adapt when those thresholds are exceeded, and if the thresholds are exceeded too often then the wetland transforms into something else.
This reminded me of how we design infrastructure and buildings. They are all designed to resist change to a pre-determined threshold: an earthquake of certain horizontal accelerations; a wind of a certain speed; a flood of a certain depth; etc. And this resist strategy works pretty well when the climate is stable. We could look at the last 100 years or so of weather data and use that to develop a probabilistic estimation of a built system’s likely performance based on the known weather extremes for each locale.
But now we know that the climate is not stable. The earth is already beginning to change. The likelihood of extreme weather events is changing. Native villages like Newtok are losing 70 feet of permafrost a year and need to move their village. Some river systems are mobilizing [pdf] sediments at accelerating rates with an increasing risk of catastrophic riverine floods, increasing localized flooding from higher groundwater levels, and storm surge in near-shore areas. As the ecosystems of the earth get closer and closer to their tipping points, climate and ecosystems may be transformed at the continental scale.
If natural systems are already adapting to climate change, how about us humans? Not so much. We still use the resist strategy in pretty much every way! Regulations and best practices throughout the world are based on resisting change. We require that roads, bridges, energy, water, wastewater systems, water supply systems, and buildings be designed to withstand events of a certain size based on the concept that climate of the past is a good proxy for the climate of the future. Even today as you drive past a road repair project it is quite likely that the contractor used a design storm of a certain intensity of the past to size the drainage system. Wastewater lines are sized by storm intensities of the past and water supply systems are based on drought experiences of the past. It’s pretty much universal: the reliability of most urban infrastructure systems are in some way based on the idea that the climate is relatively stable in any particular location.
But the climate is no longer stable. We need new strategies for designing and building infrastructure so that we provide flexibility and adaptability to the system. We need to design buildings and infrastructure that can adapt!
We can do adapt just like we can do resist. Alas, we rarely do adapt – at least so far. When we stick to resist as our only and best strategy that means that the buildings and infrastructure that surround us will be failing us more often. More often, even, than advertised. That is because many infrastructure and building projects complete a benefit: cost analysis. And how we determine whether or not an improvement is worth it to us, is in part dependent on how long it lasts! Yet when we continue to pretend that the climate of the future is the same as the climate of the past, we are setting ourselves up to create more victims and more survivors of failing systems. Irritating and uneconomic at the least or potentially catastrophic if loss of life is increased.
Resistance remains an important strategy. It’s just not our only one! Resisting what is wrong or to protect what is right is a perfectly fine strategy. Be good at it! But sometimes adaption is the way to go and the rules and norms of adaptation are different.
What about transformation? We need it and should fear it, too. Because as earth systems hasten towards this highly uncertain future, we may find shifts in ecosystems at the regional or continental scale. Yet on the other hand, transformation may be the only pathway forward if institutions continue to block adaptation.
We need to be more like a wetland. We need to resist change when we can, but if we are impacted again and again – before we recover from the last hit – we are going to need to start adapting. And if it comes down to it, we may need to transform, even if that means learn to swim like a fish or float like a duck.