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Amplified Risk: Understanding & Addressing Impacts to Communities from Geologic Hazards Affected by Climate Change

Our Amplified Risk program is analyzing and compiling current understanding of how climate change is likely to worsen geologic hazards and their impacts. The four-year, USAID-funded program is focusing on impacts likely to affect lower-resourced countries at risk from earthquakes and volcanic activity as well as the landslides and tsunamis that these events may trigger.

Building on the investigation of impacts, transdisciplinary teams from many countries will develop guidance to mitigate shifting risks, adapt to changing conditions, or prepare for the disasters that the changing climate may make more likely.

We are collaborating with officials and communities in three locations to reduce climate change-amplified local risks. The first is in the Philippines, a country at great risk from earthquakes, volcanic eruptions, and climate change impacts.


People stand amid collapsed buildings after the 2021 earthquake in southern Haiti. Two days after the earthquake, Tropical Depression Grace brought heavy rain, which slowed rescue and relief, and made life more difficult for those forced to live under tarps. Such “compound events” may become worse as hurricanes become more intense due to climate change. Photo by Voice of America (Left). Children took refuge on their school’s rooftop after a slurry of mud and debris (lahar) buried their community due to heavy typhoon rain following Mount Pinatubo’s volcanic eruption. Photo by U.S. Geological Survey (Right).

Our study reveals that there are a number of ways that climate change can amplify earthquakes, volcanic activity, and their secondary hazards. A few examples:

  1. As weather gets increasingly more severe (extreme rainfall, more frequent or severe droughts, more intense storms):

  • Earthquakes can trigger more extensive landslides on deeply saturated slopes than on drier slopes

  • Volcanic debris flows/lahars may increase in number and severity

  • Earthquakes may cause more widespread liquefaction in wet valley soils

  • Volcanic ash and other tephra becomes incredibly heavy when wet, collapsing roofs and downing power lines

  • Cycles of strong rain and drought can result in large fluctuations in reservoir levels and can trigger earthquakes

  • Low moisture and high temperature can increase the spread of post-earthquake urban and wildland fires

2. As temperatures warm, melting glaciers and snow release water and change the pressure on the underlying earth. In these conditions:

  • Volcanic debris flows/lahars may increase in number and severity

  • More explosive volcanic eruptions may result from depressurized magma chambers

  • Earthquakes may occur if the reduced pressure triggers movement along faults that were already nearly “ready” to move

3. With sea level rise, coastal erosion and extreme rain:

  • The extent of tsunami inundation can be increased

  • Coastal landslide-triggered tsunamis may increase

With increased frequency of climate change-intensified rainfall and storms, amplified events are becoming more likely to overlap with comparatively infrequent earthquakes and volcanic eruptions. When multiple hazards overlap, the resulting compound disasters often carry far worse consequences than a primary event or the separate hazards. Our team is exploring such effects and how communities can better prepare for the impacts.

Our team is developing Impact Briefs to inform communities about the range of amplified risks that may affect them locally, and about adaptations and mitigation actions that would help to reduce their risks. With guidance for disaster managers and local officials, we want the Impact Briefs to spur conversations about planning ahead for changes in their hazard and climate context.

Blog post: Climate Change Can Amplify Earthquake and Volcano Impacts


This program is made possible by the generous support of the American people through the United States Agency for International Development (USAID). This website and program products are the responsibility of GeoHazards International and do not necessarily reflect the views of USAID or the United States Government, and are based upon work supported by USAID under cooperative agreement # 720BHA22CA00035.

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