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Tsunamis are often thought of as rare, sudden disasters triggered purely by undersea earthquakes. Images of towering walls of water hitting coastlines reinforce the idea that they are geological events, separate from the slower-moving challenges of climate change. Yet while climate change does not directly cause most tsunamis, it is increasingly shaping the conditions that determine how often certain types of tsunami-like events occur and how destructive they become when they do.
Understanding this connection requires looking beyond the classic earthquake-driven tsunami and considering the broader category of large sea waves generated by landslides, ice collapse, and coastal instability. In these areas, a warming planet is quietly shifting the risk landscape.
Most major tsunamis originate from underwater earthquakes that displace large volumes of water. However, they can also be triggered by volcanic eruptions, underwater landslides, and even the collapse of glaciers into the sea. These latter mechanisms are where climate change begins to play a more noticeable role.
As global temperatures rise, ice sheets melt, permafrost thaws, sea levels increase, and weather patterns become more extreme. Each of these changes can destabilize natural structures that have long acted as barriers or anchors along coastlines and in polar regions. The result is not a simple increase in earthquake-driven tsunamis, but a higher likelihood of secondary processes that can generate large, fast-moving waves.
One of the most direct links between climate change and tsunami risk is sea level rise. As oceans expand due to warming waters and melting glaciers and ice sheets, the baseline sea level rises. This does not create tsunamis, but it dramatically worsens their impact.
A tsunami’s destructive power depends heavily on how far inland the water can travel. When sea levels are higher, even moderate tsunami waves can reach deeper into coastal communities. Areas that previously sat safely above wave reach may find themselves newly exposed.
Low-lying coastal cities, delta regions, and small island nations are especially vulnerable. Infrastructure such as ports, roads, and wastewater systems becomes more susceptible to flooding and damage. In effect, climate change amplifies the consequences of tsunamis, even when the triggering event remains unchanged.
In polar and high-altitude regions, climate change is reshaping landscapes, potentially increasing the likelihood of tsunami-like waves. As glaciers retreat, they leave behind steep, unstable valley walls that were once supported by ice. Without that support, rock faces can collapse into fjords or lakes, displacing large volumes of water.
Permafrost thaw further increases instability. Ground that was once permanently frozen is now softening, weakening slopes and coastal cliffs, and raising the risk of large landslides into nearby water bodies.
These processes are already producing real-world impacts. In 2017, a massive landslide in Greenland’s Karrat Fjord triggered a tsunami that damaged nearby villages. More dramatically, in September 2023, another Greenland landslide generated an estimated 200-meter-high tsunami and produced seismic waves detected globally, despite not being earthquake-driven. This event underscores how rapidly changing Arctic conditions can release extreme energy when unstable slopes fail.
Climate change is also increasing rainfall intensity in many regions. Heavier and more frequent downpours saturate soil, weaken slopes, and raise the likelihood of landslides. When these landslides occur near coastal cliffs, fjords, or large inland lakes, they can displace enough water to generate tsunami-like waves.
While not all landslides produce tsunamis, the combination of saturated ground, destabilized slopes, and rising temperatures is creating conditions where such events are becoming more plausible in certain regions. In some high-risk environments, particularly steep coastal and Arctic landscapes, these processes can unfold rapidly, leaving little time for warning or response.
Another indirect but important factor is coastal erosion. Rising sea levels and stronger storm surges are eroding coastlines that once served as natural buffers against wave energy. Mangroves, wetlands, coral reefs, and dunes all help reduce the force of incoming water.
Climate change is degrading many of these systems. Coral reefs, for instance, are highly sensitive to ocean warming and acidification. As they decline, coastlines lose a critical first line of defense. While reefs do not prevent tsunamis, their loss allows waves to maintain more energy as they approach shore.
Similarly, the degradation of mangroves and coastal wetlands reduces the ability of ecosystems to slow and absorb water movement. This increases the reach and intensity of flooding during tsunami events.
It is important to emphasize that climate change does not significantly influence the tectonic processes that cause most large tsunamis. Earthquakes deep beneath the ocean floor remain the primary driver of the most devastating historical events, such as the 2011 Tōhoku tsunami in Japan.
However, even in these cases, climate change can still affect outcomes. Rising sea levels mean that the same tsunami wave height can produce greater inland flooding. Coastal populations are also increasing in many parts of the world, meaning more people and infrastructure are exposed. In other words, while the frequency of earthquake-generated tsunamis may remain largely unchanged, the scale of human and economic impact is likely to grow.
The most important way to understand the relationship between climate change and tsunami risk is through the concept of compounding hazards. Climate change does not replace traditional tsunami risks — it adds layers that can intensify or expand them.
Higher seas increase flooding reach. Unstable slopes increase the likelihood of landslide-generated waves. Melting ice introduces new sources of sudden displacement. At the same time, growing coastal populations and infrastructure development increase exposure. These overlapping factors create a world where coastal hazards are no longer isolated events but interconnected risks influenced by both geological and climatic systems.
Addressing this evolving risk landscape requires more than traditional earthquake monitoring. Early warning systems must be expanded to include landslide-prone coastal regions and glacier-monitoring zones. In Arctic and fjord environments, real-time surveillance of slope stability is becoming increasingly important.
Additionally, urban planning is vital. Coastal development needs to account for higher baseline sea levels and greater wave reach. In some regions, this may mean relocating infrastructure or redesigning coastal defenses.
Nature-based solutions are also gaining attention. Restoring mangroves, wetlands, and coral reefs can help reduce wave energy and improve overall coastal resilience. While these ecosystems cannot stop tsunamis, they can reduce the severity of flooding and provide additional protection during extreme events.
Climate change is not rewriting the fundamental science of tsunamis, but it is reshaping the environments in which they occur and the damage they cause. In some regions, it is creating new pathways for tsunami-like events through landslides and ice collapse. In others, it is amplifying the reach and impact of waves driven by unrelated geological forces.
For coastal communities, the takeaway is not alarm but awareness. The risks are evolving, and so too must the systems designed to understand and manage them. As the planet continues to warm, the intersection of climate and geophysical hazards will become an increasingly important part of disaster preparedness and coastal resilience planning.
In this changing landscape, tsunamis remain rare but powerful reminders of Earth’s dynamic systems — and of the need to consider how a warming world is reshaping them.
