Rebuilding after disasters

When disasters strike—from floods, earthquakes, hurricanes, or wildfires—their destruction is immediately visible. Homes collapse, roads wash out, and communities are displaced. What is less visible, but just as consequential, is what happens next: the sudden scramble for the materials needed to rebuild.

As climate change makes disasters more frequent and severe, demand for cement, sand, gravel, timber, and steel is rising sharply. Without careful planning, post-disaster rebuilding can damage ecosystems, strain supply chains, increase greenhouse gas emissions, and undermine long-term community resilience—turning recovery into a new source of environmental risk.

Major disasters often destroy or damage tens of thousands of buildings at once. Studies of post disaster recovery consistently show that rebuilding can create the equivalent of 15 years’ worth of construction demand in just days or weeks.

The state of supply chains illustrates a lagging response to short term events, particularly in low-income or geographically isolated regions. The result is familiar across continents: shortages of basic materials, price increases of 30%–40%, and prolonged delays in recovery. And when demand for materials spikes rapidly, extraction expands especially where regulation is weakest or oversight is limited.

After the 2004 Indian Ocean tsunami, increased demand for sand fueled illegal river mining across Sri Lanka, accelerating erosion, destroying fish habitats, and damaging farmland. Following Haiti’s 2010 earthquake, expanded quarrying near Port-au-Prince degraded landscapes, polluted air and water, and consumed scarce freshwater resources.

Rivers, wetlands, forests, and coastal zones play critical roles in reducing disaster risk. They buffer floods, stabilize shorelines, regulate water flows, and support food systems. Damaging nature in the name of reconstruction increases vulnerability to the very shocks and stressors communities are trying to recover from.

Disasters generate enormous volumes of debris as earthquakes, floods, and storms leave behind mountains of concrete, masonry, metal, wood, and hazardous waste.

The 2023 Türkiye–Syria earthquake produced an estimated 100 million cubic meters of rubble, creating intractable disposal problems. After Typhoon Haiyan in the Philippines, debris clogged waterways and was dumped into wetlands, creating long-term risks to ecosystems and public health.

Yet much of this debris has value. Globally, better management practices for managing hazardous waste are available, and concrete can often be crushed and reused as aggregate, metals can be recycled locally, and treated wood can be repurposed safely. When debris is managed safely and strategically, it can reduce demand for new materials, lower emissions from transport, and create local jobs.

Construction materials have significant climate and environmental footprints. Cement—a key ingredient in concrete—is among the world’s most carbon intensive materials. Cement production accounts for roughly 6–8 percent of global carbon dioxide emissions, while concrete as a system contributes even more when pollution from mining, transport, and processing are included. Post disaster reconstruction can sharply increase cement demand in a short period, pushing emissions higher just as communities are grappling with climate driven destruction. This creates a dangerous feedback loop: rebuilding increases emissions, which in turn worsen climate impacts and amplify future disaster risk.

Sand, a key ingredient in concrete, is (after water) the world’s most consumed natural resource—over 50 billion tons each year. Sand extraction destroys habitats, alters water flows, destabilizes riverbanks and coastlines, and accelerates erosion and flooding. It degrades fisheries, causes deltas and wetlands to sink and undermines food security and livelihoods for millions of people, and often involves illegal extraction and violent crime.

The choice is not whether to rebuild, but how. Rebuilding that ignores material and environmental impacts may restore infrastructure quickly, but it leaves communities more exposed to risk over time. Rebuilding that respects ecosystems, limits emissions, and treats debris as a resource can strengthen resilience far beyond the immediate recovery period.

When governments and disaster management actors plan early, they can reduce or eliminate illegal extraction, stabilize prices, reduce waste, and protect ecosystems. When they do not, reconstruction efforts often displace harm—shifting costs to nature, neighbouring communities, and future generations. The materials used after disasters shape the world that emerges from them. Getting those choices right is essential not only for recovery, but for a liveable future.

Learn more about sustainable building materials management.