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What is climate risk?
We can limit climate risk if we know how to identify, think about, and prepare for it
July 29, 2024

As we depart from the stable climate of the last 12 thousand years, the weather patterns underpinning our lives and societies are changing, creating risk to humans, our built environment, the natural world, and the systems we rely on. The first step to minimizing bad outcomes is understanding what climate risk is and how to assess it.

Weather events and climate risk

Human-caused climate change creates weather events and climate risk. Weather events include outcomes such as days with temperatures exceeding 100°F or extreme droughts continuing longer than a year, occurring or intensifying as a result of human-caused climate change. Climate risk is the potential harm to human or natural systems resulting from exposure to weather events. Once a weather event is in motion, the only thing we can control is our exposure. But because climate risk is about potential, it’s something we can limit if we know how to identify it, think about it, and prepare for it.

The severity of a climate risk depends on the exposure that a person, place, community, or system has to a weather event and how vulnerable or prepared they are for that specific event. While you can’t control what weather outcomes occur, you can limit your exposure to weather events, which can in turn limit your risk. You can also limit your risk by increasing your preparedness, which can decrease your vulnerability. This approach of limiting exposure and increasing preparedness can be done individually and collectively.

Types of climate risk

Risks resulting from climate change fall broadly into three types: exposure risks (often called first order risks), risks of physical damage (often called second order risks), and systemic response risks (often called third order risks.) Assessing climate risk is the process of examining the types of risk that could result from a weather event and measuring the probability of those risks against a person, place, or system’s vulnerability. 

Exposure risks (first order risk)

This type of climate risk results from potential exposure of a place, community, ecosystem, or population to a weather event made more likely by climate change. For example, a local weather event in Chiapas, Mexico is drought lasting longer than 12 months (year-plus drought). The exposure risk in Chiapas to this climate hazard depends on several factors, such as the likelihood of the year-plus drought (as projected by climate models), the number of inhabitants that would experience drought impacts, and the number of rain-fed farms in the area.

Risks of physical damage (second order risk) 

This type of climate risk results from possible physical damage due to exposure to a weather event. Exposure to any weather event has the potential to physically damage the human body, nature, the built environment, or other systems.

For example, several hours of exposure to temperatures above 100°F might cause a person to experience dehydration, fainting, or heat stroke. For the natural world, exposure to this temperature might result in increased evaporation of water sources and heat stress for plants and animals. For the built environment, high temperatures might degrade materials and compromise structures.

Systemic response risks (third order risk)

Both nature and human society are complex, adaptive systems. Such systems respond in multiple ways to outside forces. Third order climate risk results from a systemic response to either exposure to a weather event (first order risk), damage resulting from that exposure (second order risk), or even the awareness of potential damage. Third order risks can be economic, political, social, or natural. Examples include real estate value changes, policy changes, human migration or labor force change, and species extinction and migration.

To use the example of wildfire, insurance companies might respond to the risk of increased wildfire exposure in a given place by raising premiums, or pulling their coverage out of that area. In this case, the systemic risk of insurance companies abandoning the area results from potential exposure to a weather event. Another systemic response might be the movement of people, like migration out of the area in response to fires, the cost of rebuilding, and the prospect of higher insurance premiums.

Just as human systems respond to risk, so do natural systems. If increased wildfire exposure results in frequent fires in a given place, burning and destroying many trees, the ripple effects could drastically alter the local ecosystem. The systemic risk to the ecosystem results from physical damage due to weather event exposure. 

Climate risk and vulnerability

Vulnerability is the probability of harm based on how prepared a place, system, community or individual is for a weather event and the resulting climate risks. Vulnerability depends on how difficult it would be to prevent, recover from, and/or respond to a weather event and resulting risks—less preparation typically means greater vulnerability. To assess climate risk, you need to consider the probability of each type of risk in relation to vulnerability or preparedness.

Every place on Earth has weather it is more or less prepared for, based on the historical norm in that place. For example, the municipal government in Anchorage, Alaska is better equipped to respond to a snowstorm than a heatwave. In Cairo, Egypt, the population is likely more prepared for a heatwave than a flood. 

Using climate model data with Probable Futures maps, you can explore future weather event projections and begin to think about the vulnerability of different places, including where you live. In many places, even outcomes that were common occurrences historically are changing: More severe outcomes are becoming more frequent and less predictable. For example, between 0.5°C and 1.5°C of warming, the amount of precipitation in the 1-in-100-year storm in New York City increases by 31 mm (1.2 inches), potentially exceeding the limits the built environment was designed for, overpowering storm sewers and disrupting transit.

In the same progression of warming from 0.5°C to 1.5°C, Seville, Spain, goes from never experiencing 113°F heat to experiencing 2 days in an average year at this record-breaking temperature. Because this kind of heat did not happen at all historically, Seville may be less prepared for risks like melting infrastructure, the need for public cooling centers, or overpowering of the electrical grid.

Preparedness can make all the difference in a place’s climate risk. As weather patterns shift with our changing climate, climate data can project future weather outcomes and help you assess climate risks. Get started exploring climate risk in the places you care about, using our maps.

Want to visualize climate risk in places you care about? Begin by exploring Probable Futures maps.