Why Are Disasters Getting Worse — And What Can We Do About It?

To understand what’s driving these changes — and how communities can protect themselves — we sat down with climate scientist Dr. Daniel Swain. In this Q&A, he breaks down the science behind today’s disasters, explains the role of trees in building resilience, and shares why there’s still reason for hope.

Q: Why do disasters seem to be getting worse?

A: We need to remember that not every natural hazard is automatically a “natural disaster.” A Category 5 hurricane in the middle of the ocean isn’t a disaster — until it hits people and infrastructure. Disasters happen when extreme weather events collide with human exposure and vulnerability. Losses are rising partly because climate change is intensifying events, but also because we’ve built more homes and infrastructure in harm’s way — creating what’s known as the “expanding bullseye effect.”

Q: How are weather patterns changing?

A: It depends on the type of storm and where you live, but one unifying factor is that a warmer atmosphere can hold more water vapor. I call this the “expanding atmospheric sponge effect.” Imagine a bigger sponge — it can soak up more water and release more when squeezed. This means both the heaviest downpours and the driest droughts are getting more extreme. Even if the number of certain storms like hurricanes or atmospheric rivers isn’t increasing everywhere, the most intense events are becoming more powerful — bringing heavier rain, higher storm surges, stronger winds, and in some places, more dangerous wildfire conditions.

Q: What role can trees play in protecting communities?

A: We know there's lots of physical and mental health benefits to having trees in the environment you interact with every day. In populated areas, trees are powerful allies against heat waves and even floods. Urban tree canopy can reduce neighborhood temperatures by 5–10°F, which can literally save lives in a heat wave. Trees also help manage water — slowing runoff, reducing flood risk, and recharging groundwater. The key is the right tree in the right place, especially in cities, where their benefits for health, resilience, and livability are huge.

Q: What can communities do to become more resilient?

A: It depends on the hazard. For floods, it could be better water management and infrastructure. For heat, trees are essential — but so is making sure cooling options like energy-efficient air conditioning are available when needed. Many of the most effective actions happen locally, where communities can make meaningful changes quickly.

Q: What are the health impacts of extreme weather?

A: Some are immediate, like injuries or deaths from the event itself. But many are longer-term: smoke from wildfires can worsen respiratory and heart conditions hundreds of miles away, heat waves can strain the body, and the stress of repeated evacuations can harm mental health. These impacts can affect millions each year, even those not directly in harm’s way.

Q: What gives you hope?

A: We can’t prevent every hazard, but we can reduce the harm they cause. Communities can adapt and become more resilient, even as climate change increases certain risks. The most effective solutions often happen at the local level, where individual and collective action can have a real impact.

Daniel Swain, PhD, is a climate scientist with the University of California’s Institute for Water Resources, part of Agriculture and Natural Resources, and a Research Partner with the National Center for Atmospheric Research based in Boulder, Colorado. 

His work focuses on how extreme weather events — such as droughts, floods, wildfires, and heat waves — are changing in a warming climate, and what those changes mean for both ecosystems and communities, especially in the western United States. A lifelong weather enthusiast, Dr. Swain is widely recognized for making complex science accessible through his research, public talks, and his popular Weather West blog.