The relationship between the risk to water security in each hydrological basin
Securing the world’s water supply is one of the greatest challenges of our time. Research at Stockholm University is now presenting an alternative method for quantifying the global risk of water scarcity. Results indicate higher risks to water supply than previously expected if accounting for the environmental conditions and governability where rain is produced.
The common idea of global water supply is rain falling on the earth’s surface and then stored in aquifers, lakes, and rivers. This idea is usually used to assess water security and the risk of water scarcity. However, a study, titled “Upwind moisture supply increases risk to water security” in Nature Water, shows how the water risks are dependent on governance and environmental conditions present upwind, which means the areas where the moisture for rain comes from.
“Water supply really originates beforehand, with moisture evaporated from land or in the ocean traveling in the atmosphere before falling as rain. This upwind moisture is commonly overlooked when assessing water availability,” says Fernando Jaramillo, associate professor of physical geography at Stockholm University and responsible for the study.
When a lake or river is shared between different countries or authorities, assessments and regulations mainly apply an upstream perspective, considering conditions in the direction upriver from the water body. Instead, an upwind perspective considers the area where evaporated water is transported before ending up as rain. The area is known as a “precipitationshed” and can cover large areas of the earth’s surface.
“For instance, in tropical South America, most of the Amazon basin is downstream of the Andes mountain range, whereas large areas of the Andes are in themselves downwind of the Amazon rainforest and depending on it, which makes these two regions dependent on each other for water supply,” says Jaramillo.
The study examined 379 hydrological basins worldwide, revealing that risks to water security are significantly higher when considering the upwind origin of water.
“With this approach, we see that 32,900 km3/year of water requirements worldwide face very high risk, a near 50% increase, compared to the 20,500 km3/year resulting from the more traditional upstream focus,” says José Posada, former doctoral student at Stockholm University and main author of the study.
Political control can have major consequences
Since a large amount of water is evaporated from plants, changes in land use can affect downwind water availability. If deforestation and agricultural development are predominant in upwind areas, the amount of moisture vegetation provides may decrease, reducing rainfall downwind and increasing the risk to water security.
“For coastal countries such as the Philippines, most of the rain comes from the sea, which means that land-use changes pose very little risk to water security. Rainfall in inland countries such as Niger, on the other hand, comes mainly from moisture that evaporates in neighboring countries such as Nigeria and Ghana. This puts many land-locked countries at high risk regarding how water security is affected by changes in land use,” says Jaramillo.
In other words, political factors such as environmental management and regulations in areas where moisture first evaporates can affect water safety in completely different areas.
“For instance, the Congo River basin, heavily reliant on moisture from neighboring countries with low environmental performance and governance according to global indicators, faces considerable risks due to potential deforestation and unregulated land use changes in neighboring areas,” says Lan Wang-Erlandsson, researcher at the Stockholm Resilience Center at Stockholm University and co-author of the study.
Environmental regulation requires an upwind perspective.
The study reveals why the lack of governability and environmental performance in a country upwind may be relevant to the water supply of a country downwind. It stresses the codependence between upstream/downwind and downstream/upwind countries.
“It is not possible to ignore the interdependence between countries. In the end, all water is connected, so we should not only mind how we manage our water resources within a region or country but also how our neighboring countries do,” says Wang-Erlandsson.
“We hope that the findings of this study can help identify where and to whom cooperation strategies and efforts can be directed to mitigate the causes of water-related tensions, including atmospheric water flows in transboundary decision-making and water governance frameworks. We stress the need for international cooperation to effectively manage upwind moisture sources,” concludes Jaramillo.
On November 8, 2018, a power line dropped into dry grass in the foothills of the Sierra Nevada mountains, north of Sacramento, and ignited the deadliest fire in California’s history. Powerful winds swept flames through Paradise and several other small towns in the tinder-dry forest, killing 85 people, destroying 18,000 structures, and causing more than $16 billion in damage.
Among the fire victims was the city’s water system, poisoned by the toxins in smoke. “Every time a home burns, it’s an open line to the atmosphere,” said Kevin Phillips, a former town manager and the district manager for the Paradise Irrigation District, which provides drinking water to more than 9,000 customers. “You are squirting water out [of lines that supply homes] at full speed and eventually [the system] depressurizes. That creates a vacuum effect and sucks in smoke with contaminants back into the system.” Smoke from burning trees, plastics — including PVC water pipes — and other materials contain benzene and other carcinogens. A year after the fire, testing revealed levels of benzene 80 times higher than the legal limit in some drinking water samples.
The road back to a healthy water supply has been long, requiring many rounds of flushing the system, testing, and replacing pipes. But this August, after seven years of work and expenditures of $40 million, the town’s new water system will be finished and all toxic substances flushed.
Flooding in Asheville washed away large water pipes and damaged backup pipes buried 25 feet underground.
From fires to floods, droughts, extreme heat, and sea level rise, climate change is taking a growing and serious toll on drinking water supplies around the world. The changes hit hardest in places with already stressed, or fragile, municipal water systems. And as such climate impacts worsen, they are forcing expensive fixes — if fixes exist at all.
“Climate change is having a significant impact on the availability of our water resources from a quality and quantity perspective,” said Alexandra Campbell Ferrari, executive director of the Center for Water Security and Cooperation. “We are not really addressing the challenges. Ultimately, we’ll be unprepared to address the floods and drought and pollution that we will continue to be faced with.”
More than half of the U.S. population drinks water that’s captured and filtered by forested lands. But with wildland fires growing in intensity, frequency, and duration, surface water supplies in those watersheds are increasingly contaminated with dissolved carbon, heavy metals, and excessive nutrients, including nitrogen and phosphorous, from burning trees and other forest materials. When fires burn houses and towns, plastic pipes and other human-made materials pollute the water system. And after the fires, mudslides often occur, washing sediment, debris, and other contaminants into surface water, compounding water quality problems.
Flooding poses a major threat to drinking water systems worldwide as the climate warms and the atmosphere holds ever more moisture. Last September, Hurricane Helene swept up the U.S. East Coast, dropping 14 inches of rain on Asheville, North Carolina, over the course of three days. The once-in-a-thousand-year deluge wiped out homes, businesses, and infrastructure in the mountain community — including the city’s water system.
The flooding washed away the large-diameter pipes that carried water from treatment plants to the rest of the system and damaged back-up pipes buried 25 feet underground. The 1,000 miles of smaller pipes in Asheville that carried water to businesses and residences were also heavily damaged.
This wreckage was even more striking because it happened to a system built in 2004, which was designed to be more resilient in the wake of a previous flood event. Officials “thought they were building the best they could with the means they had at the time,” Asheville Mayor Esther Manheimer toldTheNew York Times last year. “I don’t know how you can build a system that can withstand a 1,000-year flood situation like we just experienced. If you had all the money in the world, you probably could. When you’re a city on a budget of $250 million a year, you know, you can’t.”
“Wastewater systems are not designed for this changing climate. They were designed for an older climate that doesn’t exist anymore.”
The problem is worse in countries without, or with minimal, water infrastructure. Recent extreme flooding events in Pakistan, Niger, and Chad flooded sewers and latrines. Pathogens were washed into drinking water, which resulted in outbreaks of diarrhea and cholera. In Chad, which was already suffering from a food crisis, contaminated floodwaters also destroyed stores of food as well as crops in fields. In southern Brazil, flooding in the spring of 2024 contributed to an increase in leptospirosis in urban settings with inadequate sanitation systems.
High-intensity rain storms can also wash toxic chemicals from fertilized fields, industrial sites, and roads into streams and reservoirs. The contaminants complicate the water-treatment process as systems overflow, equipment breaks down, filters clog, and more disinfectant is required. Because many sewage and water treatment plants are built along streams and low-lying areas prone to flooding, as in Asheville, climate change is expected to damage more of these facilities. Such challenges increase the risk of contamination both immediately and over the long term.
“Wastewater systems are not designed for this changing climate,” said Sri Vedachalam. “They were designed for an older climate that probably doesn’t exist anymore.”
Wells are at risk too. Testing after Hurricane Helene showed that E. coli and coliform bacteria contaminated 40 percent of the private wells in the path of Helene. Studies have shown that flooding and heavy rains can cause human feces and other contaminants from leaky septic systems to seep into public and private wells. Some 53 million people in the United States rely on private wells, which are not regulated by the federal government and are not subject to mandatory treatment for contaminants
Droughts — made more frequent and intense by climate change — can also affect water quality. When water levels are low, organic material, such as decomposing leaves and other vegetation, gets concentrated in surface water sources, which spurs treatment plants to use more disinfectant — typically chlorine. But organic material can react with chlorine to create two families of toxic disinfection byproducts (DBP) — trihalomethanes and haloacetic acids. Utilities face a balancing act: Using too little chlorine could allow opportunistic pathogens to survive. Using too much chlorine could allow harmful DBPs to build up in drinking water. A recent analysis found some evidence that trihalomethanes, even at levels below regulatory limits in the U.S. and the European Union, increase the risk of bladder and colorectal cancer over decades of consumption; haloacetic acids are also considered a potential carcinogen.
In Mozambique, drought has led to a lack of clean water, leading to an increase in water-borne diseases like cholera.
Globally, rural areas that lack advanced water treatment systems also suffer. In Mozambique’s Nampula Province, climate-related drought has diminished rivers, shallow boreholes, and wells; the lack of clean water has contributed to rising cases of tropical diseases like scabies, schistosomiasis, and lymphatic filariasis, according to Doctors Without Borders, in addition to water-borne diseases like cholera and diarrhea. A solution: digging deeper and better-covered wells.
Fertilizer runoff and contaminated stormwater from extreme rainfall, combined with warmer water temperatures, are also increasing the frequency and intensity of harmful algal blooms in freshwater. After a massive algal bloom occurred in Lake Erie in the summer of 2014, residents of Toledo, Ohio, were warned not to drink their tap water because it contained cyanotoxins generated by thick green slicks of algae. Exposure to these naturally occurring compounds, through swimming in or drinking affected water, can cause serious illness and even death.
Experts say the risk of algal blooms, and their risk to drinking water, is growing. Lake Erie’s “blooms are starting earlier,” said Sean Corson, director of NOAA’s National Center for Coastal Ocean Science toldInside Climate News. “They’re lasting longer. Their peaks are larger. So, by some measures, they’re getting worse.”
Ocean water is also threatening drinking water supplies as river volumes decline. The Mississippi River has experienced a drought over the last two years, due to lack of precipitation and excessive heat. The low river levels have allowed saltwater to travel from the Gulf of Mexico further upstream, threatening to contaminate New Orleans’ drinking water.
“Lately it’s been an extremely low river,” said Mark “Hobbo” Cognevich, who works on water issues as a district representative for Plaquemines Parish, at the mouth of the Mississippi. “The seawater is rising and so it’s moving its way upriver against the freshwater coming down.” Saltwater intrusion has become more frequent in the last few years, said Cognevich. Last year, parish officials delivered bottled water to residents, and the utility occasionally trucks in reverse osmosis filters, or desalination units, to supplement its water treatment until a new plant in Belle Chasse with reverse osmosis capabilities can be completed.
To cope with the growing risk of fires to its water system, Paradise, California has learned hard lessons on how to prepare.
Utilities across the U.S. are working on various fronts to adapt to the changing water picture. In Paradise, to cope with the growing risk of fires, Phillips said the city has learned hard lessons on how to better prepare. “We put in concrete meter boxes everywhere so they are more resilient to heat,” he said. “We use brass meters, no more plastic meters. And every house is equipped with a backflow device, so if a house was to burn down there would no longer be the opportunity for a vacuum effect.”
According to a recent report by the Pacific Institute, the Center for Water Security and Cooperation, and DigDeep, which promotes clean-water initiatives in underserved communities, a key part of adapting to climate impacts on water systems is legal reform.
“Until our laws reflect some kind of instruction manual that says we need to think about how we are managing our water resources” — including protecting minimum stream flows and aquifer levels, reducing the amount of pollution going into water, and prioritizing equitable access to drinking water — “we aren’t going to achieve those goals,” said Ferrari, of the Center for Water Security and Cooperation. “The law creates the impetus for change.”
Water is essential to life, driving our economies and supporting the foundation of ecosystems. Yet, despite its critical role, many regions are facing severe water shortages.
Add to this the plight of a warming planet, and the result is an urgent global crisis that needs effective water management strategies.
Research conducted by Lorenzo Rosa of Carnegie Science and Matteo Sangiorgio of the Polytechnic University of Milan sheds light on the growing water crisis under various climate scenarios.
The experts emphasize a critical need for robust water policies, with insights that could prove instrumental in future preparations.
The water gap issue
A “water gap” happens when people need more water than what is available. This problem affects billions of people around the world.
The amount of water needed for drinking, farming, and industry is often more than what nature can provide. When people use too much water without allowing time for it to be replenished, natural sources like rivers, lakes, and aquifers start to dry up.
Over time, this continuous overuse creates a serious water shortage, making it harder for communities, farms, and businesses to get the water they need.
“Water scarcity is one of the greatest challenges facing humanity this century. About 4 billion people reside and about half the world’s irrigated agriculture is in regions that experience water scarcity for at least one month each year,” said Rosa.
Climate change and water shortages
The water scarcity issue is further complicated by climate change. Rising temperatures destabilize rainfall patterns, shift water cycles, and deplete natural freshwater sources.
This adds substantial strain to already fragile water systems, elevating the risk of shortages in urban and rural areas.
According to Rosa, higher temperatures accelerating evaporation rates can deplete water supplies, even in regions that have historically been stable. Unpredictable weather patterns causing droughts and floods further complicate water management.
Water demand amidst population growth
Population explosion further strains water resources with expanding cities requiring greater quantities for drinking, sanitation, and industrial usage.
Agricultural production must also increase to feed the growing population, making water conservation and management even more critical.
“We must be able to balance environmental resilience and the growing need for water in a warming world with a burgeoning population,” noted Rosa.
Rising temperatures and water shortages
The research paints a troubling picture. The baseline global water gap stands at nearly 458 billion cubic meters (121 trillion gallons) annually.
The water gap is expected to increase by 6% under 1.5°C (2.7°F) warming and by 15% under 3°C (5.4°F) warming.
“Even relatively modest increases in the water gap can put pressure on ecosystems and lead to severe shortages for agricultural use, resulting in food insecurity,” said Rosa.
Water resource management needs quick action and future planning. Building better systems to store and share water can help solve the problem. Advances in technology present possibilities like desalination of seawater and wastewater treatment and reuse.
Agriculture, a major consumer of global water, must adapt by shifting to crops that require less water or employing advanced irrigation techniques.
Finding solutions for water shortages
Rosa’s research plays an important role in finding solutions for water shortages. He is exploring ways to make irrigation more efficient so that less water is wasted.
Rosa also investigates how to keep soil moist for longer, which helps crops grow with less water. Another part of his work focuses on improving how water is stored, making sure it is available when needed.
In addition to water management, Rosa also examines how to reduce the harmful effects of fertilizer production on the environment. The goal is to make farming more sustainable, ensuring that future generations can grow food without harming natural resources.
As climate change intensifies, water shortages will continue to be a significant issue across the globe. It is essential for policymakers, researchers, and communities to collaborate on finding effective solutions.
By understanding water scarcity and exploring innovative approaches, we can work toward ensuring a sustainable water future.
Climate change impacts the world’s water in complex ways. Consider a water cycle diagram, like the one below; global warming is altering nearly every stage in the diagram. These changes will put pressure on drinking water supplies, food production, property values, and more, in the U.S. and all around the world.
Evaporation
Warmer air can hold more moisture than cool air. As a result, in a warmer world, the air will suck up more water from oceans, lakes, soil and plants. The drier conditions this air leaves behind could negatively affect drinking water supplies and agriculture.
On the flip side, the warmer, wetter air could also endanger human lives. A study out of Columbia University’s Lamont-Doherty Earth Observatory found that higher humidity will make future higher temperatures unbearable in some places, by blocking the cooling effects of our sweat.
Precipitation
When all that extra warm, extra wet air cools down, it drops extra rain or snow to the ground. Thus, a warmer world means we get hit with heavier rain and snowstorms. The northeastern U.S. is so far seeing the largest increase in the intensity and frequency of heavy precipitation events. And in the Central U.S., clusters of thunderstorms have been becoming more frequent and dropping more precipitation since 1979.
By changing air temperatures and circulation patterns, climate change will also change where precipitation falls. Some areas — such as the American West, Southwest, and Southeast — are expected to get drier. Meanwhile, the northern parts of the U.S. and the Midwest are expected to get wetter. These precipitation projections are already becoming reality.
The Southwest, southern Great Plains, and Southeast are predicted to see more intense and prolonged droughts, according to the National Climate Assessment. And most of the rest of the country is at risk of experiencing more severe short-term droughts, too. Researchers within the Earth Institute have found that climate change may already have exacerbated past and present droughts, and that drier conditions are making wildfires worse.
“The drought scenario could be mitigated by having more water storage in dams, which nobody’s working on,” Lall pointed out, “or in groundwater, which is being discussed in some places but is not that easy to do for large quantities of water.”
Changes in precipitation patterns will challenge many farmers, as well as natural ecosystems. Scientists at Columbia University’s International Research Institute for Climate and Society are creating tools and strategies to help farmers adapt to these challenges. Natural ecosystems, however, may not be able to adapt as quickly.
Surface Runoff and Stream Flow
The heavier bursts of precipitation caused by warmer, wetter air can lead to flooding, which can of course endanger human lives, damage homes, kill crops, and hurt the economy.
The America’s Water initiative at the Columbia Water Center has been working to identify the specific causes of catastrophic flooding, in order to more accurately predict them, to save lives and property. The project also made projections about how flooding will change as the world continues to warm. “On the action side, we looked at what structures like dams and levees need to be refurbished, and what zoning changes need to be done so that people are out of harm’s way?” said Lall.
Heavier rainstorms will also increase surface runoff — the water that flows over the ground after a storm. This moving water may strip nutrients from the soil and pick up pollutants, dirt, and other undesirables, flushing them into nearby bodies of water. Those contaminants may muck up our water supplies and make it more expensive to clean the water to drinking standards. The National Climate Assessment finds that water quality is already diminishing in many parts of the U.S, “particularly due to increasing sediment and contaminant concentrations after heavy downpours.”
In addition, as runoff dumps sediments and other contaminants into lakes and streams, it could harm fish and other wildlife. Fertilizer runoff can cause algae blooms that ultimately end up suffocating aquatic critters and causing a stinky mess. The problem is compounded by warming water, which can’t hold as much of the dissolved oxygen that fish need to survive. These conditions could harm fisheries, and make conditions unpleasant for folks who like to use lakes and streams for fishing, swimming, and other recreational activities.
Researchers within the Earth Institute at Columbia University are finding that green infrastructure, such as parks, wetlands, and other green areas, can help to absorb runoff and filter out its contaminants. These work on a small scale with everyday storms, although Lall notes they aren’t much help when it comes to floods.
Oceans
Warmer temperatures and increasing acidity are making life difficult for sea creatures. These changes are transforming food chains from the bottom-up. In addition, many fish are moving poleward in search of cooler waters, which has implications for the fishing industry and people who like to eat fish.
Temperature changes also have the potential to alter major ocean currents. Because ocean temperatures drive atmospheric circulation patterns, this could change weather patterns all over the world. Climate scientist Richard Seager from Columbia’s Lamont-Doherty Earth Observatory has found that higher ocean surface temperatures could make rainfall more variable, and thus less predictable, from year to year.
And of course, as ice sheets and mountaintop glaciers melt, they’re dumping extra water into the oceans; the resulting sea level rise jeopardizes coastal properties around the world.
Snowpack
Ordinarily, as winter snowpack melts in the springtime, it slowly adds fresh water to rivers and streams and helps to replenish drinking water supplies.
However, as the air warms, many areas are receiving more of their precipitation as rain rather than snow. This means less water is being stored for later as snowpack. In addition, the rain actually accelerates the melting of snow that’s already on the ground.
The lack of snowpack can lead to drier conditions later in the year, which can be bad news for regions that rely on snowmelt to refill their drinking water supplies. In California, for example, declines in snowpack have contributed to long-term drought and water shortages. At the same time, as the rains come faster rather than slowly melting from snow, California’s ability to control floods is decreasing.
A study last year out of Lamont-Doherty Earth Observatory found that increasing summer heat is driving off California’s morning clouds. This lack of clouds allows more sunlight to strike the ground, raising temperatures further, exacerbating drying and the risk of wildfires.
Changes in Water Demand
In addition to changing the water cycle, climate change could change how we use water and how much we need. Higher temperatures and evaporation rates could increase the demand for water in many areas.
Water Stress
These changes in water supply, demand, and quality will “exacerbate our current problem,” says Lall, “which is that we have aging water infrastructure across the country that is failing, and we simply do not have the capacity to deal with even historical variation, let alone what people are projecting for the future.”
Climate change will make water shortages more likely in parts of the U.S., particularly the southern U.S. and the Caribbean and Pacific islands.
An estimated 1.6 million Americans already don’t have regular access to safe drinking water. A study out of Michigan State University found that, because of climate change, aging infrastructure and other factors, up to 40.9 million American households may not be able to afford water and wastewater services in 2022.
A recent study from Harvard projects that by 2071, nearly half of the 204 fresh water basins in the United States may not be able to meet their monthly water demand. This is due in part to growing populations, but also because of the effects of climate change. Around 50 years from now, the study found, many U.S. regions may see their water supplies reduced by a third of their current size, while demand continues to increase. The authors warn this could pose serious challenges for agriculture.
What Can Be Done
Work from the Columbia Water Center could help municipalities to meet the challenges of the future; the America’s Water project has been examining how water can be allocated to prevent shortages, and where more water storage is needed to withstand future droughts.
To make these calculations, the Columbia Water Center teamed up with folks from Lamont-Doherty, using tree ring data to reconstruct droughts and floods from the last 700 years in all the major river basins in the U.S. In the process, they learned that in the 1300s and 1400s, the U.S. experienced droughts far more severe and widespread than anything we’ve seen in modern times.
“The reason for going back 700 years is that, whether or not people believe in future climate change projections, this is something that has happened, and so we should prepare for it in case it happens again,” Lall explained.
Whereas climate models always have some degree of uncertainty, he continued, with historical data, “it’s easier to convince people that, for example, if you remove some of the dams on the Colorado River, there’s really just no ability to meet even the more modest older droughts.”
Lall’s team built an open-source optimization model which allows anyone to investigate and explore different scenarios for water supply and demand in their own watershed. This tool can help to identify which crops would grow best under certain water regimes, or how adding renewable energy will affect the water supply.
Increasing water storage, making irrigation systems more efficient, and making sure crops are appropriate for the local climate are a few ways municipalities can help to stave off water stress. Wind and solar power projects can help, too, because they use less water than traditional power plants.
There are also things that the rest of us can do to help conserve water, like fixing leaky plumbing, taking shorter showers, watering the lawn less often, and avoiding foods that require a lot of water. For example, it requires 1,800 gallons of water to produce one pound of beef.
Lall also suggests that people learn more about how climate change is going to affect the water in their own region, and start taking action locally.
“In the process, you discover that your water system is inadequate to meet the challenges of climate change,” said Lall. “You will discover that the rivers that you go fishing in and jetskiing and things like that, they’re likely to become stinky swamps. Once you go through this discovery process, then it becomes much more tangible to get action at a local level, and start changing things from the bottom-up.”
A new study indicates more than 4 billion people in low- and middle-income countries (LMICs) lack access to safe drinking water, Swiss researchers reported yesterday in Science.
Combining household surveys and earth observation data (including satellite, airborne, and land-based data) with geospatial modelling techniques, a team led by researchers from the Swiss Federal Institute of Aquatic Science and Technology estimated that only 33% of the total population of 135 LMIC’s used a safely managed drinking water service (SMDWS) in 2020, leaving approximately 4.4 billion without access to safe drinking water. That’s more than twice the number of people estimated to lack access to safe drinking water in a 2020 by the World Health Organization and the United Nations (UN) Children’s Fund Joint Monitoring Programme for Water Supply, Sanitation and Hygiene.
The lowest national rates of SMDWS use were in sub-Saharan Africa. The study estimates that, in 12 countries in the region, less than 10% of the population used SMDWS in 2020.
Safe drinking water a ‘basic human right’
The study also found that access to safe drinking water in LMICs is primarily limited by fecal contamination, which affects nearly half the population in those countries and is indicated by Escherichia colicontamination in the primary drinking water source.
“Detection of fecal contamination in drinking water is concerning, as ingestion of fecal pathogens is a major driver of diarrheal disease, one of the leading causes of under-five child mortality globally,” the study authors wrote.
The authors note that access to safe drinking water is recognized as a basic human right and plays a core role in the UN’s 2030 Agenda for Sustainable Development. They add that drawing attention to the many regions lacking safe water could “inform the mobilization and effective allocation of financial resources and human capacity” to address the issue.
“By filling crucial data gaps, our results point toward a substantial underestimation of the number of people whose basic human rights to safe drinking water are not being met and provide information on which subcomponents may be limiting use of SMDWS regionally,” they wrote.
The Baku Dialogue on Water for Climate Action is intended to provide continuity between the annual UN climate negotiations and promote coherence and collaboration. It aims to ensure a consistent focus on water and its interplay with climate change, biodiversity loss, pollution, and desertification, focusing on actions at the international, regional, river and basin levels.
“Water is not just a victim of climate change but it is also a vital solution. Water is at the heart of achieving many Sustainable Development Goals. Without water there is no sustainable development,” said COP29 President Mukhtar Babayev. “Water must be integrated into full aspects of the global climate agenda.”
He said that the Caspian Sea – the world’s largest inland water body and an integral part of Azerbaijan’s national identity and economy – is shrinking, alongside the degradation of biodiversity. “This is an alarming prospect,” he said.
WMO is one of the founding partners of the Baku Dialogue on Water for Climate Action, which will be hosted by the UN Environment Programme.
The Baku Dialogue declaration resolves to:
promote dialogue and partnerships among countries at international, regional, river and basin levels,
strengthen the generation of scientific evidence on the causes and impacts of climate change on water resources, water basins and water-related ecosystems,
enhance water-related climate policy actions.
It received a ringing endorsement from speakers at a high-level side event in the closing stages of COP29.
Freshwater resources are increasingly under pressure from rising societal demands, environmental degradation and climate change.
“2023 was the driest for rivers globally in more than three decades of records. Almost half of the planet experienced lower than normal annual river flows. The world’s glaciers experienced their largest mass loss in almost fifty years of record-keeping. This is a worrying omen for future water security for billions of people,” WMO Deputy Secretary-General Ko Barrett told the high-level event.
“Water is at the heart of the international disaster risk reduction agenda and the Early Warnings for All initiative. This is essential, given that water-related hazards are the leading cause of human and economic losses in many countries,” she said.
Water is vital for climate change mitigation as a key enabler of greenhouse gas emission reductions. Water supports renewables like biofuels, hydropower, and is needed for cooling of low-emission power plants. Finally, water is essential for hydrogen and for producing minerals vital for battery technology.
“This makes the necessary green energy transition a thirsty business and is why we need integrated water and climate policies,” said Ko Barrett.
WMO Role
WMO will be a committed partner in implementation of the Baku Dialogue.
As the specialized UN agency for weather, climate and water, WMO will leverage its mandate to support informed decision-making. National Meteorological and Hydrological Services need to play a crucial role in integrating water data and information into development policies for informed decision-making. This builds on the expertise of WMO’s national hydrological advisers.
WMO is co-coordinator of the UN-Water Expert Group on Water and Climate Change, and offers comprehensive support to the UN System-wide Strategy on Water and Sanitation.
Improved water monitoring and data sharing is vital in order to improve integrated management of water resources.
Increased funding is essential to enhance water monitoring systems, implement early warning systems, and build resilience in communities vulnerable to water stress and extreme events.
The need for water action
The impacts of climate change are felt through water.
One-fifth of the world’s river basins are experiencing rapid changes in the area covered by surface waters
Glaciers have suffered the largest mass loss in 50 years.
Around 2.2 billion people still do not have access to safe drinking water, 3.5 billion lack access to safely managed sanitation,3 and at least 50% of the world’s population — around 4 billion people — live under highly water-stressed conditions, with the most vulnerable hit the hardest.
Over 90 percent of disaster-affected people and nearly 95 percent of infrastructure loss and damage were impacted by water-related disasters, while floods are one of the major sources of water pollution, threatening water quality and human health and safety.
The economic impacts of climate change on water resources are significant. Some regions could experience GDP declines of up to 6% by 2050 due to water-related impacts on agriculture, health, and incomes.
Without mitigating actions, global GDP could decrease by up to 18% by mid-century if temperatures rise by 3.2°C. These findings underscore the substantial economic risk posed by climate-induced disruptions to the hydrological cycle.
Nationally Determined Contributions
Integrating water management and cooperation into national climate policy, such as Nationally Determined Contributions and National Adaptation Plans, is crucial for effective climate adaptation and mitigation.
Understanding water availability and constraints can assist in deciding on climate change response options and guide the design of projects, reduce project risks and hence costs – a key issue as NDC 3.0 are being prepared.
Such integration ensures also a coordinated approach to managing shared water resources, enhancing resilience to climate impacts, and promoting sustainable development.
It allows countries to address water security, improve public health, and reduce climate-related vulnerabilities comprehensively across water dependent sectors.
By incorporating these elements into national climate policies, countries can leverage international cooperation to achieve their climate goals and ensure the provision of essential services
PFAS are in Miami’s rainwater. And it is the latest evidence the synthetic “forever chemicals” — that have raised health concerns for people and wildlife — hitch a ride on the water cycle, using the complex system to circulate over greater distances.
For more than a year, FIU researchers collected and analyzed 42 rainwater samples across three different sites in Miami-Dade County. A total of 21 perfluoroalkyl and polyfluoroalkyl substances, or PFAS, were detected, including PFOS and PFOA (since phased out of production over cancer concerns), as well as the newer varieties used in manufacturing today.
While profiles of several PFAS matched back to local sources, others did not. According to the study, published in Atmospheric Pollution Research, this suggests Earth’s atmosphere acts as a pathway to transport these chemicals far and wide — contributing to the worldwide pollution problem.
“PFAS are practically everywhere,” said FIU Assistant Professor of Chemistry and study author Natalia Soares Quinete. “Now we’re able to show the role air masses play in potentially bringing these pollutants to other places where they can impact surface water and groundwater.”
Widely used in consumer products — non-stick cookware, clothing, cosmetics, food packaging, detergents and firefighting foams, to name a few — PFAS were purposefully created to be almost indestructible. They don’t break down easily or simply go away. Once in the environment, they accumulate over time. People can ingest or inhale them, and exposure has been linked to liver and kidney damage, fertility issues, cancer and other diseases. The EPA warned even low levels of exposure can be dangerous, setting strict near-zero limits for some PFAS in drinking water.
It’s still unclear, though, how exactly these long-lived chemicals journey through the environment.
Quinete, who heads the Emerging Contaminants of Concern lab in FIU’s Institute of Environment, has been trying to piece this picture together.
Her research group is among the first to extensively track the prevalence of the persistent pollutants across South Florida. They’ve detected PFAS in drinking water and surface water including Biscayne Bay. And, subsequently, also found PFAS in animals that live in those areas, including oysters and economically important recreational fish and lobsters. Rain was the natural next place for the team to look.
PFAS can infiltrate the atmosphere by either evaporation or getting absorbed into microscopic particles and dust. Wind and shifting air currents shuttle them along. Eventually, it rains. As each drop falls to earth, it brings along some of the pollutants. The cycle begins and ends and begins again.
This played out in the team’s data.
Between October 2021 and November 2022, the most frequently detected and abundant PFAS in Miami’s rainwater, in 74% of samples, were PFCAs — commonly used in non-stick and stain-resistant products, food packaging and firefighting foams. The researchers previously detected high levels of these compounds in nearby surface waters, a sign they’re coming from local sources.
However, a noticeable shift occurred at certain times of year. PFAS concentrations suddenly skyrocketed during the dry season (October through May), coinciding with Northeastern air masses moving into Miami. More emerging PFAS also made an appearance including those typically found in North Carolina and other states, where facilities produce goods made with these particular chemicals.
“The season variations were interesting to us,” said Maria Guerra de Navarro, a graduate student in Quinete’s lab who helped lead the study. “We know there are northern states with manufacturing that matches back to the PFAS we saw, so it’s likely that’s where they are coming from.”
Here’s what the researchers suspect is happening: Drier air in northern currents creates perfect conditions for more PFAS-laden dust and particles to spread around. Rain “washing out” those pollutants from the air could account for higher contaminant concentrations. Guerra de Navarro is currently examining this kind of dry deposition, measuring how many PFAS can be packed into particles smaller than 10 microns — seven times smaller than the strand of a human hair (70 microns).
As with their past research, the team hopes the data can help guide future solutions and regulations for controlling and reducing PFAS.
“This is all about creating awareness that this is all one world,” says Guerra de Navarro. “What’s happens in one area can impact here, there, everywhere. We have to be thinking about how to prevent these chemicals from going all over the world.”
POSTVILLE, Iowa — A nonprofit environmental group has filed a federal lawsuit against Agri Star Meat & Poultry, alleging the Iowa meatpacking plant has repeatedly violated the Clean Water Act by discharging pollutants into Hecker Creek and the Yellow River.
Driftless Water Defenders, represented by Public Justice, FarmSTAND, and Larew Law Office, filed the lawsuit Monday in the U.S. District Court for the Northern District of Iowa. The legal action follows a 60-day notice period during which the group warned of its intent to sue, citing years of self-reported permit violations and a lack of enforcement from state regulators.
According to the complaint, Agri Star’s Postville facility has “discharged and continues to discharge pollutants” beyond legal limits, including ammonia nitrogen, total suspended solids, chloride, oil and grease, and biochemical oxygen demand. The lawsuit seeks declaratory and injunctive relief, financial penalties of up to $68,445 per day per violation, and court-ordered compliance measures.
“Agri Star has repeatedly violated the terms of its Clean Water Act permit over the course of many years,” said Daniel C. Snyder, director of the Environmental Enforcement Project at Public Justice, according to a Monday press release announcing the lawsuit. “The state has failed to secure Agri Star’s compliance with binding federal law. As a result, Driftless Water Defenders is doing exactly what Congress intended: acting as a private attorneys general to enforce the Clean Water Act when government regulators fail to do so.”
The lawsuit claims Agri Star has continued polluting Hecker Creek, a tributary of the Yellow River, despite holding a National Pollutant Discharge Elimination System permit issued by the Environmental Protection Agency, which contracts the Iowa Department of Natural Resources to carry out enforcement. The complaint alleges Iowa DNR has failed to carry out appropriate enforcement and that the meatpacking company has not only exceeded permitted pollutant levels, but also failed to conduct required water quality sampling and report results for additional contaminants.
Driftless Water Defenders President Chris Jones said in the press release that Iowa’s waterways are a public resource and must be protected. “The Yellow River has traditionally been one of Iowa’s recreational crown jewels—clean water where citizens can fish, hike, canoe and kayak,” he said. “If governmental agencies won’t enforce our clean water laws, citizens must step in to do that.”
Agri Star has a history of regulatory scrutiny. Last March, the company discharged 250,000 gallons of untreated beef processing waste into Postville’s wastewater system, causing a two-day shutdown of the city’s water treatment facility. According to the complaint, this followed at least five prior enforcement actions against the company by the U.S. Environmental Protection Agency.
Driftless Water Defenders’ notice of intent to sue, sent Dec. 23, cited violations including Agri Star’s September 2024 discharge of 1,149 pounds of ammonia nitrogen per day—more than ten times its permitted limit of 97 pounds. The same month, the plant allegedly released 19,165 pounds of total suspended solids per day, exceeding the legal limit of 293 pounds by a factor of 65.
Attorney James C. Larew, representing the plaintiffs, said the group had hoped Agri Star would take meaningful compliance measures after receiving the 60-day notice but received no such indication. “In filing a citizen suit, we intend to protect these vital resources as authorized and intended by the law,” Larew said in the press release.
Iowa DNR has previously told Iowa’s News Now that it is considering enforcement action against Agri Star for chloride violations and has issued a notice of violation. DNR officials have said Agri Star has struggled to meet new chloride limits that took effect in August 2024 and could face further penalties if it does not come into compliance.
The complaint calls for immediate compliance with permit limits, new pollution control technology, and additional staffing and training to ensure proper environmental management.
“People have the right to enjoy their local waterways, in the Driftless Region and everywhere,” said FarmSTAND attorney Holly Bainbridge in the press release. “After 60 days of notice, it’s time to enforce the Clean Water Act through the courts and make Agri Star stop polluting the Yellow River and Hecker Creek.”
Hydraulic fracturing, or “fracking,” is the process of injecting water, chemicals and sand into horizontal wells under high pressure to crack rock and release oil and gas.
Even though the oil and gas industry often uses a restrictive definition of “fracking” that refers only to the moment in the extraction process where the rock is fractured, the impacts of fracking go far beyond some broken rock.
What is fracking and why is it bad for the environment?
There are many activities needed to bring a gas or oil well into production, and all of them have environmental impacts.
Fracking requires a lot of water. More than 100,000 gallons of water are used to create a fracking well. Once the well is created, even more water and toxic chemicals are used to operate it.
Once the well has produced gas or oil, transporting it also carries environmental costs. The construction of infrastructure like pipelines and roads can change the shape of a landscape forever, decimating and fragmenting habitat that wildlife need to survive.
Fracking pollutes waterways
Fracking has polluted both groundwater and surface waterways such as rivers, lakes and streams.
Pollution can enter our waterways at several points in the fracking process. Fracking fluid can leak or spill as it is transported to the site of the well, mixed with chemical additives, and pumped from place to place. Fracking also involves highly pressurizing that liquid — so damage to the well infrastructure can result in blowouts that spew wastewater into the environment.
Wastewater from the fracking process is produced in enormous volumes – both as “flowback” immediately after fracking, and “produced water” over a longer period while a well is producing oil and gas. Fracking operators have no safe, sustainable way of dealing with this toxic waste.
Fracking waste contains dangerous pollutants. The toxic substances in fracking chemicals and wastewater have been associated with a variety of negative health effects, including cancer, endocrine disruption, and neurological and immune system problems.
Researchers at the Yale School of Public Health analyzed more than 1,000 chemicals found in fluid fracking and wastewater. Toxicity data were not available for many of them, but of the chemicals for which toxicity data were available, 65% were toxic.
That means at least 15% of the chemicals used in fracking are toxic or dangerous to human health – and the true number might be much higher.
And fracking doesn’t simply pollute water. It also removes water from the water supply both for us and the broader environment.
Each well that is fracked requires hundreds of thousands or millions of gallons of water. Unlike most industrial uses of water, in which water returns to the water cycle for further use, water used in fracking typically can’t be cleaned up for a broad range of other uses.
Water from fracking usually either remains in the well, is “recycled” to frack new wells, or is disposed of in deep injection wells. Injecting the water deep underground keeps it separate from natural aquifers, meaning that fracking takes billions of gallons out of the water supply annually.
Fracking damages wild places
Well pads, new access roads, pipelines and other infrastructure built for fracking turn forests and rural landscapes into industrial zones. Infrastructure to support fracking has directly damaged at least 679,000 acres of land since 2005. That’s an enormous area, just slightly smaller than Yosemite National Park.
What does developing the land to support new fracking wells mean for wild places and critical wildlife habitat?
Before drilling can begin, the land at the well site must be clear-cut and leveled so that drilling equipment, gas collection and processing equipment, and vehicles can operate. The removal of trees and plants completely destroys habitat wildlife need to survive, and leaves the soil vulnerable to erosion.
And the destruction doesn’t stop at the well site itself. Additional land must be cleared for roads to the well site, as well as for any pipelines and compressor stations needed to deliver gas to market. Roads can be especially dangerous to wildlife. By one estimate, each fracking well is responsible for more than 3,000 one way truck trips over its lifetime. Without wildlife crossings, that means a lot of animals end up as roadkill.
Overall, the development of natural gas infrastructure results in up to 23 acres of land cover disturbance per well pad.
Even habitat that isn’t directly destroyed can be damaged. The “edge habitat” surrounding an industrialized area becomes degraded and vulnerable to the spread of invasive plants.
Fracking harms wildlife
The loss of habitat associated with fracking, and the impacts of the operation of fracking wells, can have serious detrimental effects on wild animals.
Fracking creates air pollution that can seriously impact wildlife. A Colorado study revealed that exposure to air pollution from fracking could cause neurological problems, respiratory diseases, and cancer in wild animals.
The loud machines and bright lights of industrial fracking areas can change animals’ behavior and interfere with their ability to make use of the habitat they have left near fracking sites. Research on mule deer in Colorado found that the number of deer living on land essential to the species’ wintertime survival declined by 25 to 50 percent near gas and drilling operations.
The fragmentation of habitat associated with fracking development is especially hard on bird species that depend on large tracts of undisturbed habitat to survive. Endangered cerulean warblers, who need deep forest habitat, are experiencing population declines across their range, but researchers noted that the decline was 15 percent higher near fracking sites than in the wider region. Species such as the northern harrier, snowy owl, rough-legged hawk and American kestrel rely on 30 to 100 acres of undisturbed grassland for breeding or wintering habitat, which developments like pipelines and roads can fracture.
The clearing of land for well pads, roads and pipelines also threaten aquatic ecosystems by increasing sedimentation of nearby waterways and decreasing shade. One study found an association between increased density of gas drilling activity and degradation of ecologically important headwater streams.
Water contamination related to fracking can cause fish to die. After fracking equipment failed at an Ohio site in 2014, a fire broke out, causing trucks to explode and thousands of gallons of toxic chemicals to leak into an Ohio River tributary. More than 70,000 fish were killed by the pollution.
In a recently published paper, NASA scientists use nearly 20 years of observations to show that the global water cycle is shifting in unprecedented ways. The majority of those shifts are driven by activities such as agriculture and could have impacts on ecosystems and water management, especially in certain regions.
“We established with data assimilation that human intervention in the global water cycle is more significant than we thought,” said Sujay Kumar, a research scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and a co-author of the paper published in the Proceedings of the National Academy of Sciences.
The shifts have implications for people all over the world. Water management practices, such as designing infrastructure for floods or developing drought indicators for early warning systems, are often based on assumptions that the water cycle fluctuates only within a certain range, said Wanshu Nie, a research scientist at NASA Goddard and lead author of the paper.
“This may no longer hold true for some regions,” Nie said. “We hope that this research will serve as a guide map for improving how we assess water resources variability and plan for sustainable resource management, especially in areas where these changes are most significant.”
One example of the human impacts on the water cycle is in North China, which is experiencing an ongoing drought. But vegetation in many areas continues to thrive, partially because producers continue to irrigate their land by pumping more water from groundwater storage, Kumar said. Such interrelated human interventions often lead to complex effects on other water cycle variables, such as evapotranspiration and runoff.
Nie and her colleagues focused on three different kinds of shifts or changes in the cycle: first, a trend, such as a decrease in water in a groundwater reservoir; second, a shift in seasonality, like the typical growing season starting earlier in the year, or an earlier snowmelt; and third a change in extreme events, like “100-year floods” happening more frequently.
The scientists gathered remote sensing data from 2003 to 2020 from several different NASA satellite sources: the Global Precipitation Measurement mission satellite for precipitation data, a soil moisture dataset from the European Space Agency’s Climate Change Initiative, and the Gravity Recovery and Climate Experiment satellites for terrestrial water storage data. They also used products from the Moderate Resolution Imaging Spectroradiometer satellite instrument to provide information on vegetation health.
“This paper combines several years of our team’s effort in developing capabilities on satellite data analysis, allowing us to precisely simulate continental water fluxes and storages across the planet,” said Augusto Getirana, a research scientist at NASA Goddard and a co-author of the paper.
The study results suggest that Earth system models used to simulate the future global water cycle should evolve to integrate the ongoing effects of human activities. With more data and improved models, producers and water resource managers could understand and effectively plan for what the “new normal” of their local water situation looks like, Nie said.
