Sara Hughes, University of Michigan and Michael Wilson, Pardee RAND Graduate School

Water scarcity is often viewed as an issue for the arid American West, but the U.S. Northeast’s experience in 2024 shows how severe droughts can occur in just about any part of the country.

Cities in the Northeast experienced record-breaking drought conditions in the second half of 2024 after a hot, dry summer in many areas. Wildfires broke out in several states that rarely see them.

By December, much of the region was experiencing moderate to severe drought. Residents in New York City and Boston were asked to reduce their water use, while Philadelphia faced risk to its water supply due to saltwater coming up the Delaware River.

Before the drought, many people in the region weren’t prepared for water shortages or even paying much attention to their water use.

As global temperatures rise, cities throughout the U.S. are more likely to experience hotter, drier conditions like this. Those conditions increase evaporation, drying out vegetation and soil and lowering groundwater tables.

The Northeast drought was easing in much of the region in early 2025, but communities across the U.S. should take note of what happened. They can learn from the experiences of cities that have had to confront major water supply crises – such as Cape Town, South Africa; São Paulo, Brazil; Melbourne, Australia; Las Vegas; and New Orleans – and start planning now to avoid the worst impacts of future droughts.

Lessons from cities that have seen the worst

Our new analysis of these five cities’ experiences provides lessons on how to avoid a water supply crisis or minimize the effects through proactive policies and planning.

Many cities have had to confront major water supply crises in recent years. Perhaps the most well-known example is Cape Town’s “Day Zero.”

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After three years of persistent drought in the region, Cape Town officials in fall 2017 began a countdown to Day Zero – the point at which water supplies would likely run so low that water would be turned off in neighborhoods and residents would need to fetch a daily allocation of water at public distribution points. Initially it was forecast to occur in April 2018.

Water rates were raised, and some households installed flow restrictors, which would automatically limit the amount of water that could be used. Public awareness and conservation efforts cut water consumption in half, allowing the city to push back its estimate for when Day Zero would arrive. And when the rains finally came in summer 2018, Day Zero was canceled.

A second example is São Paulo, which similarly experienced a severe drought between 2013 and 2015. The city’s reservoirs were reduced to just 5% of their capacity, and the water utility reduced the pressure in the water system to limit water use by residents.

Water pricing adjustments were used to penalize high water users and reward water conservation, and a citywide campaign sought to increase awareness and encourage conservation. As in Cape Town, the crisis ended with heavy rains in 2016. Significant investments have since been made in upgrading the city’s water distribution infrastructure, preventing leaks and bringing water to the city from other river basins.

Planning ahead can reduce the harm

The experiences of Cape Town and São Paulo – and the other cities in our study – show how water supply crises can affect communities.

When major changes are made to reduce water consumption, they can affect people’s daily lives and pocketbooks. Rapidly designed conservation efforts can have harmful effects on poor and vulnerable communities that may have fewer alternatives in the event of restrictions or shutoffs or lack the ability to pay higher prices for water, forcing tough choices for households between water and other necessities.

Planning ahead allows for more thoughtful policy design.

For example, Las Vegas has been grappling with drought conditions for the past two decades. During that time, the region implemented water-conservation policies that focus on incentivizing and even requiring reduced water consumption.

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Since 2023, the Las Vegas Valley Water District has implemented water rates that encourage conservation and can vary with the availability of water supplies during droughts. In its first year alone, the policy saved 3 billion gallons of water and generated US$31 million in fees that can be used by programs to detect and repair leaks, among other conservation efforts. A state law now requires businesses and homeowner associations in the Las Vegas Valley to remove their decorative grass by the end of 2026.

Since 2002, per capita water use in Las Vegas has dropped by an impressive 58%.

Solutions and strategies for the future

Most of the cities we studied incorporated a variety of approaches to building water security and drought-proofing their community – from publishing real-time dashboards showing water use and availability in Cape Town to investing in desalination in Melbourne.

But we found the most important changes came from community members committing to and supporting efforts to conserve water and invest in water security, such as reducing lawn watering.

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There are also longer-term actions that can help drought-proof a community, such as fixing or replacing water- and energy-intensive fixtures and structures. This includes upgrading home appliances, such as showers, dishwashers and toilets, to be more water efficient and investing in native and drought-tolerant landscaping.

Prioritizing green infrastructure, such as retention ponds and bioswales, that help absorb rain when it does fall and investing in water recycling can also diversify water supplies.

Taking these steps now, ahead of the next drought, can prepare cities and lessen the pain.

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Sara Hughes, Adjunct Professor of Environment and Sustainability, University of Michigan and Michael Wilson, Professor of Policy Analysis, Pardee RAND Graduate School

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Timothy J McCoy, Smithsonian Institution and Sara Russell, Natural History Museum

A bright fireball streaked across the sky above mountains, glaciers and spruce forest near the town of Revelstoke in British Columbia, Canada, on the evening of March 31, 1965. Fragments of this meteorite, discovered by beaver trappers, fell over a lake. A layer of ice saved them from the depths and allowed scientists a peek into the birth of the solar system.

Nearly 60 years later, NASA’s OSIRIS-REx mission returned from space with a sample of an asteroid named Bennu, similar to the one that rained rocks over Revelstoke. Our research team has published a chemical analysis of those samples, providing insight into how some of the ingredients for life may have first arrived on Earth.

Born in the years bracketing the Revelstoke meteorite’s fall, the two of us have spent our careers in the meteorite collections of the Smithsonian Institution in Washington, D.C., and the Natural History Museum in London. We’ve dreamed of studying samples from a Revelstoke-like asteroid collected by a spacecraft.

Then, nearly two decades ago, we began turning those dreams into reality. We joined NASA’s OSIRIS-REx mission team, which aimed to send a spacecraft to collect and return an asteroid sample to Earth. After those samples arrived on Sept. 24, 2023, we got to dive into a tale of rock, ice and water that hints at how life could have formed on Earth.

The CI chondrites and asteroid Bennu

To learn about an asteroid – a rocky or metallic object in orbit around the Sun – we started with a study of meteorites.

Asteroids like Bennu are rocky or metallic objects in orbit around the Sun. Meteorites are the pieces of asteroids and other natural extraterrestrial objects that survive the fiery plunge to the Earth’s surface.

We really wanted to study an asteroid similar to a set of meteorites called chondrites, whose components formed in a cloud of gas and dust at the dawn of the solar system billions of years ago.

The Revelstoke meteorite is in a group called CI chondrites. Laboratory-measured compositions of CI chondrites are essentially identical, minus hydrogen and helium, to the composition of elements carried by convection from the interior of the Sun and measured in the outermost layer of the Sun. Since their components formed billions of years ago, they’re like chemically unchanged time capsules for the early solar system.

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So, geologists use the chemical compositions of CI chondrites as the ultimate reference standard for geochemistry. They can compare the compositions of everything from other chondrites to Earth rocks. Any differences from the CI chondrite composition would have happened through the same processes that formed asteroids and planets.

CI chondrites are rich in clay and formed when ice melted in an ancient asteroid, altering the rock. They are also rich in prebiotic organic molecules. Some of these types of molecules are the building blocks for life.

This combination of rock, water and organics is one reason OSIRIS-REx chose to sample the organic-rich asteroid Bennu, where water and organic compounds essential to the origin of life could be found.

Evaporites − the legacy of an ancient brine

Ever since the Bennu samples returned to Earth on Sept. 24, 2023, we and our colleagues on four continents have spent hundreds of hours studying them.

The instruments on the OSIRIS-REx spacecraft made observations of reflected light that revealed the most abundant minerals and organics when it was near asteroid Bennu. Our analyses in the laboratory found that the compositions of these samples lined up with those observations.

The samples are mostly water-rich clay, with sulfide, carbonate and iron oxide minerals. These are the same minerals found in CI chondrites like Revelstoke. The discovery of rare minerals within the Bennu samples, however, surprised both of us. Despite our decades of experience studying meteorites, we have never seen many of these minerals.

We found minerals dominated by sodium, including carbonates, sulfates, chlorides and fluorides, as well as potassium chloride and magnesium phosphate. These minerals don’t form just when water and rock react. They form when water evaporates.

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We’ve never seen most of these sodium-rich minerals in meteorites, but they’re sometimes found in dried-up lake beds on Earth, like Searles Lake in California.

Bennu’s rocks formed 4.5 billion years ago on a larger parent asteroid. That asteroid was wet and muddy. Under the surface, pockets of water perhaps only a few feet across were evaporating, leaving the evaporite minerals we found in the sample. That same evaporation process also formed the ancient lake beds we’ve seen these minerals in on Earth.

Bennu’s parent asteroid likely broke apart 1 to 2 billion years ago, and some of the fragments came together to form the rubble pile we know as Bennu.

These minerals are also found on icy bodies in the outer solar system. Bright deposits on the dwarf planet Ceres, the largest body in the asteroid belt, contain sodium carbonate. The Cassini mission measured the same mineral in plumes on Saturn’s moon Enceladus.

We also learned that these minerals, formed when water evaporates, disappear when exposed to water once again – even with the tiny amount of water found in air. After studying some of the Bennu samples and their minerals, researchers stored the samples in air. That’s what we do with meteorites.

Unfortunately, we lost these minerals as moisture in the air on Earth caused them to dissolve. But that explains why we can’t find these minerals in meteorites that have been on Earth for decades to centuries.

Fortunately, most of the samples have been stored and transported in nitrogen, protected from traces of water in the air.

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Until scientists were able to conduct a controlled sample return with a spacecraft and carefully curate and store the samples in nitrogen, we had never seen this set of minerals in a meteorite.

An unexpected discovery

Before returning the samples, the OSIRIS-REx spacecraft spent over two years making observations around Bennu. From that two years of work, researchers learned that the surface of the asteroid is covered in rocky boulders.

We could see that the asteroid is rich in carbon and water-bearing clays, and we saw veins of white carbonate a few feet long deposited by ancient liquid water. But what we couldn’t see from these observations were the rarer minerals.

We used an array of techniques to go through the returned sample one tiny grain at a time. These included CT scanning, electron microscopy and X-ray diffraction, each of which allowed us to look at the rock at a scale not possible on the asteroid.

Cooking up the ingredients for life

From the salts we identified, we could infer the composition of the briny water from which they formed and see how it changed over time, becoming more sodium-rich.

This briny water would have been an ideal place for new chemical reactions to take place and for organic molecules to form.

While our team characterized salts, our organic chemist colleagues were busy identifying the carbon-based molecules present in Bennu. They found unexpectedly high levels of ammonia, an essential building block of the amino acids that form proteins in living matter. They also found all five of the nucleobases that make up part of DNA and RNA.

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Based on these results, we’d venture to guess that these briny pods of fluid would have been the perfect environments for increasingly complicated organic molecules to form, such as the kinds that make up life on Earth.

When asteroids like Bennu hit the young Earth, they could have provided a complete package of complex molecules and the ingredients essential to life, such as water, phosphate and ammonia. Together, these components could have seeded Earth’s initially barren landscape to produce a habitable world.

Without this early bombardment, perhaps when the pieces of the Revelstoke meteorite landed several billion years later, these fragments from outer space would not have arrived into a landscape punctuated with glaciers and trees.

Timothy J McCoy, Supervisory Research Geologist, Smithsonian Institution and Sara Russell, Professor of Planetary Sciences, Natural History Museum

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Ashley Bosa, Boise State University

When a wildfire notification goes off on your mobile phone, it can trigger all kinds of emotions and confusion.

You might glance outside and see no smoke. Across the street, your neighbors have mixed reactions: One is leisurely walking their dog, another is calmly packing a small bag, while a third appears to be preparing for an extended vacation.

The notification advises you to grab your “go bag,” but then panic can set in as you realize you don’t have one ready. So, you scour the local emergency management website for guidance and discover how much you’ve overlooked: important documents such as birth certificates, an extra flashlight, your children’s medications, a phone charger.

Before you can gather your thoughts, a second notification arrives – this time telling you to evacuate.

Packing the car, wrangling children or a skittish cat, figuring out where to go – it can feel frenzied in the face of danger. As you pull out, you join a traffic jam on your street, with a black smoke plume rising nearby and neighbors still loading their cars.

This chaos highlights a worst-case scenario for wildfire evacuations – one that can cause delays, heighten risks for evacuees and complicate access for emergency responders. It’s why researchers like me who study natural hazards are developing ways to help communities recognize where residents may need the most help and avoid evacuation bottlenecks in the face of future disasters.

The importance of being prepared

Confusion is common in the face of disasters, and it underscores the need for communities and individuals to be prepared.

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Delays in evacuating, or the inability to evacuate safely, can have catastrophic consequences, not only for those trying to flee but also for the first responders and emergency managers working to manage the crisis. These delays often stem from a lack of preparedness or uncertainty about when and how to act.

A study of survivors of an Australian wildfire that killed 172 people in the state of Victoria in 2009 found that two-thirds of survivors reported that they had carried out an existing disaster plan, while researchers found the majority of those who died either didn’t follow a disaster plan or couldn’t. Forecasters had warned that high temperatures were coming with very low humidity, and public alerts had gone out about the high fire risk. https://www.youtube.com/embed/Wq4VCI2JwgM?wmode=transparent&start=0 Residents had little time to evacuate as the Eaton Fire spread into Altadena, Calif., on Jan. 7, 2025. Source: NBC.

How people perceive risks and the environmental and social cues around them – such as how much smoke they see, their neighbors’ choices or the wording of the notification – will directly affect the speed of their response.

Past experience with a disaster evacuation also has an impact. Rapid population growth in recent years in the wildland-urban interface – areas where human development meets wildfire-prone areas – has meant that more people with little or no experience with wildfires are living in fire-risk areas. Wildland areas also tend to have fewer evacuation routes, making mass evacuations more difficult and time-consuming.

Adding to the complexity is the fact that large wildfires are occurring in regions not historically prone to such events and during times of the year traditionally considered outside of wildfire season. This shift has left communities and emergency response teams grappling with unprecedented challenges, particularly when it comes to evacuations.

Computer models can help spot risks

To address these challenges, researchers are developing systems to help communities model how their residents are likely to respond in the event of a disaster.

The results can help emergency crews understand where bottlenecks are likely to occur along evacuation routes, depending on the timing of the notice and the movement of the fire. They can also help fire managers understand where neighborhoods may need to be notified faster or need more help evacuating.

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My team at the Hazard and Climate Resilience Institute at Boise State University is working on one of these projects. We have been surveying communities across Idaho and Oregon to assess how people living in the wildland-urban interface areas perceive wildfire risks and prepare for evacuations.

Using those surveys, we can capture household-level decision data, such as which evacuation routes these residents would take, how many cars they plan to drive and where they would evacuate to.

We can also gauge how prepared residents would be to evacuate, or whether they would likely stay and try to defend their home instead.

With that data, we can simulate how long it will take emergency response teams to evacuate an entire community safely. The models could also show where difficulties with evacuations might be likely to arise and help residents understand how they can adjust their evacuation plans for a safer escape for everyone.

Bridging the gap between awareness and action

One of the key goals of this research is to bridge the gap between awareness and action.

While many residents in wildfire-prone areas understand the risks, translating that knowledge into concrete preparations remains a challenge. The concept of a “go bag,” for example, is widely promoted but often poorly understood. Essential items such as medications, important documents and pet supplies are frequently overlooked until it’s too late.

Clear and timely communication during wildfire crises is also essential. Evacuation warning messages such as “Ready, Set, Go!” are designed to prompt specific actions, but their effectiveness depends on residents understanding and trusting the system. Delayed responses or mixed signals can create confusion.

As wildfire risk rises for many communities, preparedness is no longer optional – it’s a necessity. Emergency notifications vary by state and county, so check your local emergency management office to understand what to expect and sign up for alerts. Being prepared can help communities limit some of the most devastating impacts of wildfires.

Ashley Bosa, Postdoctoral Researcher, Hazards and Climate Resilience Institute, Boise State University

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This article is republished from The Conversation under a Creative Commons license. Read the original article.