A jet drops fire retardant on the Bobcat Fire, 10 Sept 2020, California. (David McNew/Getty Images)

We Need to Manage a Careful Retreat From Climate Change, Scientists Urge

21 JUNE 2021

It's imperative that human societies factor a strategic 'managed retreat' into the ways they respond and adapt to climate change, researchers say, and figuring out how is a conversation that needs to be happening now.

 

Managed retreat is the coordinated movement of people and buildings away from risks, which, in the context of climate change, are approaching from numerous fronts, including sea level rise, flooding, extreme heat, wildfire, and other hazards.

While the notion of retreat may be an unpopular idea, it's vital that we reframe the conversation around what managed retreat really is, researchers say, to give ourselves the best chance of facing climate change with a full set of viable options that will be effective in the long term.

"Climate change is affecting people all over the world, and everyone is trying to figure out what to do about it," says disaster researcher A.R. Siders from the University of Delaware.

"One potential strategy, moving away from hazards, could be very effective, but it often gets overlooked."

Amidst other forms of adaptation actions – academically categorized as resistance, accommodation, avoidance, and advance – retreat is often looked down upon, researchers say. But it's important, they urge, given the scale of the climate crisis, that we don't view retreat as a form of defeat.

"Retreat has often been viewed as a failure to adapt or considered only when all other options are exhausted," Siders and co-author Katharine Mach, a climate risk researcher from the University of Miami, explain in their new study.

 

"But this conceptualization ignores lessons from numerous disciplines drawing on a long history of human movement and limits adaptation researchers and decision-makers in preparing for a broad range of futures."

In the new research, Siders and Mach review existing scientific literature on the strategy of managed retreat, and outline a roadmap of what a successful, strategic retreat from climate change might look like in the future.

Notably, they say, future managed retreat instances will be different from instances of managed retreat in the past, focused on localized, isolated, and smaller-scale disasters.

"For example, in the United States, voluntary home buyouts have helped ~45,000 families move out of flood-prone homes over the past 30 years," the researchers write.

"This represents a tiny fraction of the millions at risk [now and in the future] and is fewer than the number of homes experiencing repeat flood damage and the number of new homes built in floodplains."

Looking ahead, managed retreat could become a core element that complements other forms of response to climate change.

In addition to leaving areas outright, managed retreat could encompass making physical room for technological adaptations designed to withstand the effects of climate, such as building floating settlements, or encircling cities with storm or fire barriers.

 

It's likely that many future incarnations of managed retreat won't resemble forms we've seen in the past, which have mostly occurred in response to flooding. While flood risk and coastal inundation are certainly part of climate change, other hazards – such as wildfires and their smoke – mean new kinds of retreats will be needed.

"Future retreat may also increasingly result from slower-onset trends, such as continuing subsidence, recurrent high-tide flooding, permafrost melt, groundwater salinization, or desertification," the authors explain.

"Proactive retreat, planned before slow-onset changes severely threaten lives, livelihoods, and other things people value, is likely to be more effective and to reduce the psychological, sociocultural, and implementation burdens of retreat."

To successfully anticipate and plan for these problems, stakeholders will need to communicate across local, regional, national, and even international communities, involving both citizens, multiple levels of government, and the private sector too, the researchers say.

At the same time, managed retreat needs to absorb new kinds of adaptation visions influenced by architecture, environmental engineering, climate fiction, futurism, and security assessments – all places that could provide fresh ideas to help tackle the problems we are now facing.

"Adaptation visions have the potential to be bold, in pursuit of futures prepared for climate shocks that promote social justice, improve quality of life, and foster stronger relationships between peoples and between people and nature," the researchers explain.

"Strategic, managed retreat may not be implemented in many places. Yet bringing it into adaptation conversations now, despite (or even because of) its complexities, creates better chances of long-term, sustainable well-being under intensifying climate risks."

The findings are reported in Science.