Summary:Kelp forests bounce back faster from marine heatwaves when shielded inside Marine Protected Areas. UCLA researchers found that fishing restrictions and predator protection strengthen ecosystem resilience, though results vary by location.Share:
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Marine Protected Areas give kelp forests a recovery edge after heatwaves, showing that local protections can buffer global climate pressures. Credit: Shutterstock
New research finds that Marine Protected Areas can boost the recovery of globally important kelp forests following marine heatwaves. The findings are published in the British Ecological Society’s Journal of Applied Ecology.
Using four decades of satellite images, University of California, Los Angeles (UCLA) researchers have looked at impacts Marine Protected Areas (MPAs) are having on kelp forests along the coast of California.
They found that although the overall effect of MPAs on kelp forest cover was modest, the benefits became clear in the aftermath of marine heatwaves in 2014-2016, when kelp forests within MPAs were able recover more quickly, particularly in southern California.
“We found that kelp forests inside MPAs showed better recovery after a major climate disturbance compared to similar unprotected areas.” Explained Emelly Ortiz-Villa, lead author of the study and a PhD researcher at UCLA Department of Geography.
“Places where fishing is restricted and important predators like lobsters and sheephead are protected saw stronger kelp regrowth. This suggests that MPAs can support ecosystem resilience to climate events like marine heatwaves.”
Professor Rick Stafford, Chair of the British Ecological Society Policy Committee, who was not involved in the study said: “It’s great to see these results and they clearly show that local action to protect biodiversity and ecosystem function can help prevent changes caused by global pressures such as climate change.
“However, it also demonstrates the need for effective MPAs. In this study, all the MPAs examined regulated fishing activity, and this is not the case for many sites which are designated as MPAs worldwide – including many in the UK.”
Kelp forests: a globally important and threatened ecosystem
Kelp forests our found around coastlines all over the world, particularly in cool, temperate waters such as the pacific coast of North America, The UK, South Africa, and Australia.
These complex ecosystems are havens for marine wildlife, including commercially important fish, and are one of the most productive habitats on Earth. They’re also efficient in capturing carbon and protect coastlines by buffering against wave energy.
However, kelp forests across the west coast of North America have declined in recent yeadue to pressures such as marine heatwaves, made more frequent and intense with climate change, and predation from increasing numbers of sea urchins, which have benefitted from population collapses of sea stars, which predate them.
Kyle Cavanaugh, a senior author of the study and professor in the UCLA Department of Geography and Institute of the Environment and Sustainability said: “Kelp forests are facing many threats, including ocean warming, overgrazing, and pollution. These forests can be remarkably resilient to individual stressors, but multi-stressor situations can overwhelm their capacity to recover. By mitigating certain stressors, MPAs can help enhance the resilience of kelp.”
Marine protected areas as a conservation tool
MPAs are designated areas of the ocean where human activity is limited to support ecosystems and the species living there. However, protections vary widely and while some areas are no-take zones, others have few restrictions or lack comprehensive management and enforcement. Many even allow destructive practices like bottom trawling.
Effective MPAs form a key part of the Kunming-Montreal Global Biodiversity Framework, agreed at COP15 in 2022, which commits nations to protecting at least 30% of oceans and land by 2030.
“Our findings can inform decisions about where to establish new MPAs or implement other spatial protection measures.” said Kyle Cavanaugh. “MPAs will be most effective when located in areas that are inherently more resilient to ocean warming, such as regions with localized upwelling or kelp populations with higher thermal tolerance.”
Emelly Villa added: “Our findings suggest that kelp forests could be a useful indicator for tracking the ecological health and climate resilience of protected areas and should be included in long-term monitoring strategies.”
Measuring the impact of marine protected areas
To understand the effects MPAs were having on kelp, the researchers used of satellite data from 1984-2022 to compare kelp forests inside and outside of 54 MPAs along the California coast.
By matching each MPA with a reference site with similar environmental conditions, they were able to test whether MPAs helped kelp forests resist loss or recover from extreme marine heatwaves which took place in the North pacific between 2014 and 2016.
The researchers warn that while their findings show that MPAs can help kelp recovery after marine heatwaves, the effect was highly variable depending on location.
“On average, kelp within MPAs showed greater recovery than in the reference sites. However, not all MPAs outperformed their corresponding reference sites, suggesting that additional factors are also play a role in determining resilience.” said Kyle Cavanaugh.
The researchers say that future work could look to identify these factors to better understand where and when MPAs are most effective at enhancing kelp resilience.
The Nepalese government plans to improve sanitation access to combat water-borne diseases, while the monsoon season further complicates health problems in the country.
Twenty people have died from water-borne diseases while more than 400 cases of acute watery diarrhea have been recorded so far this year in Nepal, according to IRIN.
While the South Asian country has the second largest freshwater resource in the world it suffers from limited drinking water sources due to pollution and disease. Roughly 15 million people, about half the population, face drinking water shortages, while another 5 million don’t have access to safe drinking water, according to the Federation of Drinking Water and Sanitation Users Nepal, an organization that monitors water and sanitation. And with monsoon season in full effect–it runs from about mid-April to mid-October–major drinking water problems are worsening. In 2009, Nepal recorded 370 deaths and 67,000 cases of AWD during the six-month period, according to the Nepal Red Cross. Women, children and the elderly are often the most effected.
To combat these illnesses, the Nepalese government intends to expand access to toilets from 14.4 million to 19 million people by 2011, the The Himalayan reports.
Flooding, unsanitary dumping, agriculture and political confrontation have lead to further pollution of ground and surface water as well as a damaged water infrastructure.
“With water sources drying up, erratic rainfall and poor management of water resources, the problems are worsening every year,” said Prakash Amatya the director of NGO Forum for Urban Water & Sanitation.
More than 80 percent of diseases reported in Nepal stem from unsafe drinking water and poor hygiene, according to a 2009 report released by Water Aid, an international NGO that strives to improve water access and sanitation for communities. The report, End Water Poverty, reveals that 10,500 children die before the age of five every year from diseases contracted from unsafe water, which includes dysentery, hepatitis and cholera.
“This situation could affect a large number of families who have already been reeling under the immense water shortage situation over the last many years,” Ajaya Dixit, director of the Nepal Water Conservation Foundation, a non-partisan NGO that researches water issues in the Himalaya-Ganga region, told IRIN.
Meanwhile communities higher up in the Himalayas have limited access to the five tributaries of the River Ganges that serve as Nepal’s main water sources. These people live on less than 5 liters of water per person per day, according to a 2004 report from the University in Kathmandu.
Water deficiencies contribute to political turmoil both within Nepal and the region itself, according to Dan Smith, the secretary general of International Alert, an independent peace building organization that works in more than 20 countries.
Nepal is embedded between India and China, which also have large agriculture demands that consume a majority of the Himalayan water. A recently proposed Indian dam project on the trans-boundary Kosi River that is a tributary of the Ganges river, has caused political and social uproar within Nepal, reports The Himalayan.
An environment-friendly plastic lost over 80% of its mass after 13 months underwater real-time deep-sea conditions.
Summary:A new eco-friendly plastic called LAHB has shown it can biodegrade even in the extreme environment of the deep ocean, unlike conventional plastics that persist for decades. In real-world underwater testing nearly a kilometer below the surface, LAHB lost more than 80% of its mass after 13 months, while traditional PLA plastic remained completely intact. The secret? Colonies of deep-sea microbes actively broke down the material using specialized enzymes, converting it into harmless byproducts like CO and water.
Researchers submerged LAHB films at a depth of 855 m near Hatsushima Island to test real-world deep-sea biodegradation. After 13 months, the LAHB plastic lost over 80% of its mass, showing its potential as a safer alternative to conventional plastics that persist in marine ecosystems. Credit: Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
Researchers have demonstrated a new eco-friendly plastic that decomposes in deep ocean conditions. In a deep-sea experiment, the microbially synthesized poly(d-lactate-co-3-hydroxybutyrate) (LAHB) biodegraded, while conventional plastics such as a representative bio-based polylactide (PLA) persisted. Submerged 855 meters (~2,800 feet) underwater, LAHB films lost over 80% of their mass after 13 months as microbial biofilms actively broke down the material. This real-world test establishes LAHB as a safer biodegradable plastic, supporting global efforts to reduce marine plastic waste.
Despite the growing popularity of bio-based plastics, plastic pollution remains one of the world’s most pressing environmental issues. According to the OECD’s Global Plastics Outlook (2022), about 353 million metric tons of plastic waste were produced globally in 2019, with nearly 1.7 million metric tons flowing directly into aquatic ecosystems. Much of this waste becomes trapped in large rotating ocean currents, known as gyres, forming the infamous “garbage patches” found in the Pacific, Atlantic, and Indian Oceans.
To tackle this, researchers have been searching for plastics that can be degraded more reliably in deep-sea environments. One promising candidate is poly(d-lactate-co-3-hydroxybutyrate) or LAHB, a lactate-based polyester biosynthesized using engineered Escherichia coli. So far, LAHB has shown strong potential as a biodegradable polymer that breaks down in river water and shallow seawater.
Now, in a study made available online on July 1, 2025, and published in Volume 240 of the journal Polymer Degradation and Stability on October 1, 2025, researchers from Japan have shown for the first time that LAHB can also get biodegraded under deep-sea conditions, where low temperatures, high pressure, and too limited nutrients make breakdown of plastic extremely difficult. The study was led by Professor Seiichi Taguchi at the Institute for Aqua Regeneration, Shinshu University, Japan, together with Dr. Shun’ichi Ishii from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Japan and Professor Ken-ichi Kasuya from Gunma University Center for Food Science and Wellness, Japan.
“Our study demonstrates for the first time that LAHB, a microbial lactate-based polyester, undergoes active biodegradation and complete mineralization even on the deep-sea floor, where conventional PLA remains completely non-degradable,” explains Prof. Taguchi.
The research team submerged two types of LAHB films — one containing about 6% lactic acid (P6LAHB) and another with 13% lactic acid (P13LAHB) — alongside a conventional PLA film for comparison. The samples were submerged at a depth of 855 meters near Hatsushima Island, where deep-sea conditions, cold temperatures (3.6 °C), high salinity, and low dissolved oxygen levels make it hard for microbes to degrade plastic.
After 7 and 13 months of immersion, the LAHB films revealed clear signs of biodegradation under deep-sea conditions. The P13LAHB film lost 30.9% of its weight after 7 months and over 82% after 13 months. The P6LAHB film showed similar trends. By contrast, the PLA film showed no measurable weight loss or visible degradation during the same period, underscoring its resistance to microbial degradation. The surfaces of the LAHB films had developed cracks and were covered by biofilms made up of oval- and rod-shaped microbes, indicating that deep-sea microorganisms were colonizing and decomposing the LAHB plastic. The PLA film, however, remained completely free of biofilm.
To understand how the plastic decomposes, the researchers analyzed the plastisphere, the microbial community that formed on the plastic’s surface. They found that different microbial groups played distinct roles. Dominant Gammaproteobacterial genera, including Colwellia, Pseudoteredinibacter, Agarilytica, and UBA7957, produced specialized enzymes known as extracellular poly[3-hydroxybutyrate (3HB)] depolymerases. These enzymes break down long polymer chains into smaller fragments like dimers and trimers. Certain species, such as UBA7959, also produce oligomer hydrolases (like PhaZ2) that further cleave these fragments, splitting 3HB-3HB or 3HB-LA dimers into their monomers.
Once the polymers are broken down into these simpler building blocks, other microbes, including various Alpha-proteobacteria and Desulfobacterota, continue the process by consuming the monomers like 3HB and lactate. Working together, these microbial communities ultimately convert the plastic into carbon dioxide, water, and other harmless compounds that ideally return to the marine ecosystem.
The findings of this study fill a critical gap in our understanding of how bio-based plastics degrade in remote marine environments. Its proven biodegradability makes it a promising option for creating safer, more biodegradable materials.
“This research addresses one of the most critical limitations of current bioplastics — their lack of biodegradability in marine environments. By showing that LAHB can decompose and mineralize even in deep-sea conditions, the study provides a pathway for safer alternatives to conventional plastics and supports the transition to a circular bioeconomy,” says Prof. Taguchi.
Summary:In 2023, the world’s oceans experienced the most intense and widespread marine heatwaves ever recorded, with some events persisting for over 500 days and covering nearly the entire globe. These searing ocean temperatures are causing mass coral bleaching and threatening fisheries, while also signaling deeper, system-wide climate changes.
Marine heatwaves surged to record-breaking levels in 2023, disrupting ecosystems and fisheries across 96% of the ocean. Scientists warn this may mark the beginning of a fundamental climate shift. Credit: Shutterstock
The global marine heatwaves (MHWs) of 2023 were unprecedented in their intensity, persistence, and scale, according to a new study. The findings provide insights into the region-specific drivers of these events, linking them to broader changes in the planet’s climate system. They may also portend an emerging climate tipping point. Marine heatwaves (MHWs) are intense and prolonged episodes of unusually warm ocean temperatures.
These events pose severe threats to marine ecosystems, often resulting in widespread coral bleaching and mass mortality events. They also carry serious economic consequences by disrupting fisheries and aquaculture. It’s widely understood that human-driven climate change is driving a rapid increase in the frequency and intensity of MHWs.
In 2023, regions across the globe, including the North Atlantic, Tropical Pacific, South Pacific, and North Pacific, experienced extreme MHWs. However, the causes underlying the onset, persistence, and intensification of widespread MHWs remain poorly understood.
To better understand the MHWs of 2023, Tianyun Dong and colleagues conducted a global analysis using combined satellite observations and ocean reanalysis data, including those from the ECCO2 (Estimating the Circulation and Climate of the Ocean-Phase II) high-resolution project.
According to the findings, MHWs of 2023 set new records for intensity, duration, and geographic extent, lasting four times the historical average and covering 96% of the global ocean surface. Regionally, the most intense warming occurred in the North Atlantic, Tropical Eastern Pacific, North Pacific, and Southwest Pacific, collectively accounting for 90% of the oceanic heating anomalies.
The researchers show that the North Atlantic MHW, which began as early as mid-2022, persisted for 525 days, while the Southwest Pacific event broke prior records with its vast spatial extent and prolonged duration. What’s more, in the Tropical Eastern Pacific, temperature anomalies peaked at 1.63 degrees Celsius during the onset of El Niño.
Using a mixed-layer heat budget analysis, the scientists discovered diverse regional drivers contributing to the formation and persistence of these events, including increased solar radiation due to reduced cloud cover, weakened winds, and ocean current anomalies. According to the researchers, the 2023 MHWs may mark a fundamental shift in ocean-atmosphere dynamics, potentially serving as an early warning of an approaching tipping point in Earth’s climate system.
QARAOUN, Lebanon (Reuters) -Water levels at Lebanon’s largest reservoir on the Litani River have fallen to historic lows amid what experts describe as the country’s worst drought on record, threatening agriculture, electricity production, and domestic water supplies.
The Litani River National Authority said inflows to Lake Qaraoun during this year’s wet season did not exceed 45 million cubic metres, a fraction of the 350 million cubic metres annual average.
Last year, the figure stood at 230 million. The water currently available in Lake Qaraoun – around 61 million cubic meters – was unusable due to severe pollution, the authority said.
“There were dry years in 1989, 1990 and 1991, but this year is the driest,” said Sami Alawieh, head of the river authority. “We are facing a water scarcity problem across all Lebanese territories and water basins.”
Drone footage of Lake Qaraoun shows a dramatically receded shoreline, exposing cracked earth and dead vegetation.
Lebanon’s hydroelectric plants tied to the Litani basin have been shut down, Alawieh said, causing financial losses and intensifying electricity rationing by Electricite du Liban.
“We have two factors: the decline in rainfall and the pressure on groundwater,” he said.
A study by the authority found climate warming and shifting weather patterns have contributed to more frequent dry seasons and higher temperatures, exacerbating soil moisture loss and reducing the recharging of groundwater reservoirs.
The state utility has slashed supply in some areas from 20 hours a day to as little as 10.
In the fertile area around Qaraoun village, in the Bekaa Valley, farmers were already feeling the impact.
“I have never seen such drought or scarcity of rain as this year,” said Safa Issa. “We used to get snow up to a metre high. Now, it’s been 10 years since we’ve seen any.”
The strain has been compounded by erratic supply of electricity needed to run irrigation systems.
“You irrigate for three hours, then stop for three,” said Fayez Omais, another local farmer.
Suzy Hoayek, an adviser to the Ministry of Energy and Water in Beirut, said a nationwide awareness campaign to reduce consumption would be launched within 10 days.
“The most important thing is to manage demand,” she said.
Summary:Hawaiian coral reefs may face unprecedented ocean acidification within 30 years, driven by carbon emissions. A new study by University of Hawai‘i researchers shows that even under conservative climate scenarios, nearshore waters will change more drastically than reefs have experienced in thousands of years. Some coral species may adapt, offering a glimmer of hope, but others may face critical stress.Share:
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Coral and red urchin in Maui, Hawai’i. Credit: Andre Seale
Across the globe, oceans are acidifying as they absorb carbon dioxide from the atmosphere, threatening coral reefs and many other marine organisms. A new study, led by oceanographers at the University of Hawai’i at Mānoa, revealed that unprecedented levels of ocean acidification are expected around the main Hawaiian Islands within the next three decades.
Increased ocean acidification has the potential to harm marine life by weakening the shells and skeletons of organisms such as corals and clams, amplifying the effects of existing stressors, and threatening ocean-based ecosystems. However, researchers have hope, as some organisms have shown signs of adapting to the changing waters. The study helps researchers, conservationists and policymakers understand the future challenges facing Hawaiian coral reefs and provides information for preserving these critical ecosystems for future generations.
Researchers within the laboratory group of Brian Powell, professor in the Department of Oceanography at the UH Mānoa School of Ocean and Earth Science and Technology (SOEST), used advanced, fine-scale computer models to project how ocean chemistry around the main Hawaiian Islands might change over the 21st century under different climate scenarios based on how much carbon dioxide societies continue to emit.
“We found that ocean acidification is projected to increase significantly in the surface waters around the main Hawaiian Islands, even if carbon emissions flatline by mid-century in the low emission scenario,” said Lucia Hošeková, lead author of the paper and research scientist in SOEST. “In all nearshore areas these increases will be unprecedented compared to what reef organisms have experienced in many thousands of years.”
Emissions shape coral reef future
The extent and timing of these changes vary depending on the amount of carbon added to the atmosphere. In the high‐emission scenario, the team found that ocean chemistry will become dramatically different from what corals have experienced historically, potentially posing challenges to their ability to adapt. Even in the low‐emission scenario, some changes are inevitable, but they are less extreme and occur more gradually.
The team calculated the difference between projected ocean acidification and acidification that corals in a given location have experienced in recent history. They refer to this as ‘novelty’ and discovered that various areas of the Hawaiian Islands may experience acidification differently. Windward coastlines consistently exhibited higher novelty, that is, future conditions deviate more dramatically from what coral reefs have experienced in recent history.
“We did not expect future levels of ocean acidification to be so far outside the envelope of natural variations in ocean chemistry that an ecosystem is used to,” said Tobias Friedrich, study co-author and research scientist in the Department of Oceanography. “This is the first ocean acidification projection specifically for Hawaiian waters to document that.”
Coral’s potential to adapt
Previous studies have shown that a coral that is exposed to slightly elevated ocean acidity can acclimatize to those conditions, thereby enhancing the coral’s adaptability.
“The results show the potential conditions of acidification that corals may experience; however, the extremity of the conditions varies based on the climate scenario that the world follows. In the best case, corals will be impacted, but it could be manageable. This is why we continue new research to examine the combined effects of stresses on corals,” said Powell. “This study is a big first step to examine the totality of changes that will impact corals and other marine organisms and how it varies around the islands.”
Colorado River Basin Suffers from a Warm and Dry Spring
Officials, farmers, and others who depend on the Colorado River received a grim prediction last week that Lake Powell, the second largest reservoir in the basin, will receive less than half of the yearly median amount of water over the next three months, which could mean cutbacks in the future.
The Colorado River carves through the Grand Canyon | Credit: Grand Canyon NPS
The snowpack at the beginning of April was less than normal, and the spring has been very warm and dry in the Rocky Mountains, which has led to low runoff.
Currently, Lake Powell is at 31 percent capacity, and Lake Mead, the largest reservoir in the country, is at 32 percent after about 25 years of severe drought. A study done three years ago showed that the drought in the Western U.S. was the driest two decades in the last 1,200 years.
Officials in the seven states of the Colorado River Basin, including Utah, Wyoming, Colorado, New Mexico, Arizona, Nevada, and California, met last week and have yet to come to an agreement on how they will share water in the coming years after the existing guidelines expire at the end of 2026. If no agreement is reached, the federal government will likely impose its own plan, which could lead to much litigation.
Meanwhile, a new study is showing that ground and surface water in the Colorado River Basin have been depleted during the last 20 years by an amount that is equivalent to the total capacity of Lake Mead. NASA satellite imagery shows the severity of the region’s crisis. Jay Famiglietti, the senior author of the study and a professor at Arizona State University, toldthe Guardian that groundwater is disappearing nearly 2.5 times faster than surface water. He added that everyone in the U.S. should be worried about the crisis in the Southwest, because much of the country’s food is grown there. In addition, the river provides drinking water to 40 million people in the U.S. and Mexico.
High Court Decision Could Allow Oil Trains along the Colorado River
A controversial plan to transport crude oil by rail along portions of the Colorado River is much closer to becoming a reality after the U.S. Supreme Court overturned a lower court’s decision blocking it.
Amtrak’s California Zephyr train travels along the Colorado River near McCoy, Colorado. | Credit: Tony Webster/Creative Commons
Environmental groups and Eagle County, Colorado, home of Vail Ski Resort, had challenged an agency decision that permitted the two-mile-long trains to ship crude oil from Utah’s Uintah Basin to the Gulf Coast. They argued that the Surface Transportation Board did not weigh the downstream effects should a tanker derail and pollute the Colorado River, threatening the environment and communities. Additionally, they said the agency had not considered how refining five billion gallons of additional oil per year would exacerbate global warming.
An appellate court agreed, but the Supreme Court, in a unanimous decision, with Justice Gorsuch recusing himself, decided that some judges have incorrectly reviewed an agency decision under the National Environmental Policy Act (NEPA) and used it to block or slow down many projects. All three of the Court’s liberal justices agreed with the decision, which has a much broader effect than just the potential of endangering people and the environment by oil tankers that could derail.
Justice Kavanaugh, writing for the Court, said that overly intrusive judicial review has led to delay upon delay and higher costs. NEPA, he continued, is to inform decision-making, not paralyze it. NEPA requires federal agencies to assess the environmental effects of proposed major actions prior to making decisions. However, this case narrows the scope of all environmental reviews of major infrastructure projects like highways and pipelines.
Earlier, the Supreme Court severely reduced environmental regulation by limiting rules on water pollution and runoff and allowing long-standing agency actions to be challenged in court, according to the Washington Post. The Court has also cut away at the ability of the EPA to regulate greenhouse gas emissions and air pollution.
Darkening Oceans Raises Concerns about Food Webs and Fisheries
The world’s oceans are getting darker. That’s the conclusion of a new study out last week that says there’s cause for concern.
According to researchers from the University of Plymouth, 21 percent of the global ocean—an area spanning more than 75 million sq km—has darkened over the past two decades. | Credit: Naja Bertolt Jensen / Unsplash
“Ocean darkening” occurs when sunlight and moonlight can’t penetrate the upper layers of the ocean called the “photic zone,” which is home to 90 percent of all marine life and one of the most productive habitats on Earth. According to researchers from the University of Plymouth in the UK, over one-fifth (21 percent) of the global ocean—around 75 million square kilometers—has darkened over the past two decades.
Typically, darkening can occur near coastlines because of agricultural runoff and increased rainfall making the waters murkier. However, this new research shows that it’s happening in the open ocean, which they suggest could be from hotter temperatures causing increased algal blooms that reduce light penetration below the surface. It could also be the result of changes in ocean circulation patterns driven by global warming.
The researchers used data from NASA’s Ocean Color Web, which breaks the global ocean down into a series of 9km pixels, to assess the changes and found that the most prominent shifts in photic zone depth in the open ocean were at the top of the Gulf Stream and around both the Arctic and Antarctic—areas of the planet experiencing the most pronounced shifts as a result of climate change. Conversely, the team also found around ten percent of the ocean had become lighter during the same study period.
The authors suggest that a shrinking photic zone in the upper ocean where marine organisms grow, hunt, reproduce, and photosynthesize, would create intense competition for resources and negatively affect food webs and global fisheries.
The word kuleana in the Hawai‘an language means a responsibility, right, or privilege to take care of one another—and to take care of the ‘āina—the land. Those terms were invoked when, on May 27, Governor Josh Green, MD, signed into law Act 96 (Senate Bill 1396) that establishes a “Green Fee” that will add a tax on hotel stays to protect the environment in the face of climate change. It’s a first for the state—and for the country.
On May 27, Hawai‘i Governor Josh Green signed into law Act 96 (Senate Bill 1396) that establishes a “Green Fee” that will add a tax on hotel stays to protect the environment in the face of climate change. | Credit: Hawai‘i Governor Josh Green, M.D./Flickr
The new “climate impact fee” is a response to the increased risk of natural disasters driven by global warming, like the wildfires on Maui in 2023. The revenue will provide a stable source of funding for environmental stewardship, hazard mitigation, and sustainable tourism, which together will enhance the islands’ resiliency.
The new law raises the amount of the current transient accommodations tax or TAT by 0.75 percent, or roughly $3 on a $400 hotel room per night. It will also apply to short-term rentals as well as to cruise ships—a sector that has long gone untaxed. The Green Fee is projected to generate $100 million annually, when it goes into effect in January 2026.
As the online publication Travel And Tour Worldreports, Hawai‘i joins a list of places around the globe like Greece, Bali, and the Galápagos Islands, where fees are being implemented in recognition that tourism, while economically vital, must be managed responsibly to protect the fragile ecosystems—that many people come to see—from the growing impacts of climate change.
Water scarcity threatens the health and development of communities around the globe. Climate change is intensifying the problem, pushing governments to find more innovative, collaborative ways to address water stress.
New Delhi residents fill containers with drinking water from a municipal tanker in June 2018. Adnan Abidi/Reuters
Water scarcity happens when communities can’t fulfill their water needs, either because supplies are insufficient or infrastructure is inadequate. Today, billions of people face some form of water stress.
Countries have often cooperated on water management. Still, there are a handful of places where transboundary waters are driving tensions, such as the Nile Basin.
Climate change will likely exacerbate water stress worldwide, as rising temperatures lead to more unpredictable weather and extreme weather events, including floods and droughts.
Introduction
Billions of people around the world lack adequate access to one of the essential elements of life: clean water. Although governments and aid groups have helped many living in water-stressed regions gain access in recent years, the problem is projected to get worse due to global warming and population growth. Meanwhile, a paucity of international coordination on water security has slowed the search for solutions.
Water stress can differ dramatically from one place to another, in some cases causing wide-reaching damage, including to public health, economic development, and global trade. It can also drive mass migrations and spark conflict. Now, pressure is mounting on countries to implement more sustainable and innovative practices and to improve international cooperation on water management.
Water stress or scarcity occurs when demand for safe, usable water in a given area exceeds the supply. On the demand side, the vast majority—roughly 70 percent—of the world’s freshwater is used for agriculture, while the rest is divided between industrial (19 percent) and domestic uses (11 percent), including for drinking. On the supply side, sources include surface waters, such as rivers, lakes, and reservoirs, as well as groundwater, accessed through aquifers.
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But scientists have different ways of defining and measuring water stress, taking into account a variety of factors including seasonal changes, water quality, and accessibility. Meanwhile, measurements of water stress can be imprecise, particularly in the case of groundwater. “Any numbers out there have to be taken with a grain of salt,” says Upmanu Lall, a Columbia University professor and water expert. “None of these definitions are typically accounting for groundwater usage, or groundwater stock.”
What causes water scarcity?
Water scarcity is often divided into two categories: physical scarcity, when there is a shortage of water because of local ecological conditions; and economic scarcity, when there is inadequate water infrastructure.
The two frequently come together to cause water stress. For instance, a stressed area can have both a shortage of rainfall as well as a lack of adequate water storage and sanitation facilities. Experts say that even when there are significant natural causes for a region’s water stress, human factors are often central to the problem, particularly with regard to access to clean water and safe sanitation. Most recently, for example, the war in Ukraine damaged critical infrastructure, leaving six million people with limited or no access to safe water in 2022.
“Almost always the drinking water problem has nothing to do with physical water scarcity,” says Georgetown University’s Mark Giordano, an expert on water management. “It has to do with the scarcity of financial and political wherewithal to put in the infrastructure to get people clean water. It’s separate.”
At the same time, some areas that suffer physical water scarcity have the infrastructure that has allowed life there to thrive, such as in Oman and the southwestern United States.
A variety of authorities, from the national level down to local jurisdictions, govern or otherwise influence the water supply. In the United States, more than half a dozen federal agencies deal with different aspects of water: the Environmental Protection Agency (EPA) enforces regulations on clean water, while the Federal Emergency Management Agency (FEMA) prepares for and responds to water disasters. Similar authorities exist at the state and local levels to protect and oversee the use of water resources, including through zoning and rehabilitation projects.
Which regions are most water-stressed?
The Middle East and North Africa (MENA) is the worst off in terms of physical water stress, according to most experts. MENA receives less rainfall than other regions, and its countries tend to have fast-growing, densely populated urban centers that require more water. But many countries in these regions, especially wealthier ones, still meet their water needs. For example, the United Arab Emirates (UAE) imports nearly all of its food, alleviating the need to use water for agriculture. The UAE and other wealthy MENA countries also rely heavily on the desalination of abundant ocean water, albeit this process is an expensive, energy-intensive one.
Water Stress Is a Global Challenge
Darker shaded areas have more physical water stress; but myriad factors, including infrastructure, governance, and population, all contribute to water availability.
Physical water stress in 2014, defined as withdrawals as a share of renewable surface and groundwater supplies> 80%40–80%20–40%10–20%< 10%Arid and low water useDCABE
+-
One in three members of the Navajo Nation lacks running water, while non-Navajos nearby generally have indoor plumbing.A
For centuries, Italy’s aquifers provided easy access to clean water, but the now outdated infrastructure is putting pressure on the country.B
The DRC has over half of Africa’s water reserves, but millions of Congolese don’t have access to clean water, contributing to disease and malnutrition.C
On top of Yemen’s physical water scarcity, years of war have wiped out water services, leaving millions without basic water supplies.D
India is among the most water-stressed countries, in part due to its population, pollution, and the exploitation of groundwater.E
Sources: National Geographic; Navajo Water Project; UNICEF; World Resources Institute; WRI Aqueduct.
Meanwhile, places experiencing significant economic scarcity include Central African countries such as the Democratic Republic of Congo, which receives a lot of rain but lacks proper infrastructure and suffers from high levels of mismanagement.
Even high-income countries experience water stress. Factors including outdated infrastructure and rapid population growth have put tremendous stress on some U.S. water systems, causing crises in cities including Flint, Michigan, and Newark, New Jersey.
How is climate change affecting water stress?
For every 1°C (1.8°F) increase in the global average temperature, UN experts project a 20 percent dropin renewable water resources. Global warming is expected to increase the number of water-stressed areas and heighten water stress in already affected regions. Subtropical areas, such as Australia, the southern United States, and North African countries, are expected to warm and suffer more frequent and longer droughts; however, when rainfall does occur in these regions, it is projected to be more intense. Weather in tropical regions will likewise become more variable, climate scientists say.
Agriculture could become a particular challenge. Farming suffers as rainfall becomes more unpredictable and rising temperatures accelerate the evaporation of water from soil. A more erratic climate is also expected to bring more floods, which can wipe out crops an overwhelm storage systems. Furthermore, rainfall runoff can sweep up sediment that can clog treatment facilities and contaminate other water sources.
In a 2018 report, a panel consisting of many of the world’s top climate researchers showed that limiting global warming to a maximum 1.5°C (2.7°F) above preindustrial levels—the aim of the Paris Agreement on climate—could substantially reduce the likelihood of water stress in some regions, such as the Mediterranean and southern Africa, compared to an unchecked increase in temperature. However, most experts say the Paris accord will not be enough to prevent the most devastating effects of climate change.
What are its impacts on public health and development?
Prolonged water stress can have devastating effects on public health and economic development. More than two billion people worldwide lack access to safe drinking water; and nearly double that number—more than half the world’s population—are without adequate sanitation services. These deprivations can spur the transmission of diseases such as cholera, typhoid, polio, hepatitis A, and diarrhea.
At the same time, because water scarcity makes agriculture much more difficult, it threatens a community’s access to food. Food-insecure communities can face both acute and chronic hunger, where children are more at risk of conditions stemming from malnutrition, such as stunting and wasting, and chronic illnesses due to poor diet, such as diabetes.
Even if a water-stressed community has stable access to potable water, people can travel great lengths or wait in long lines to get it—time that could otherwise be spent at work or at school. Economists note these all combine [PDF] to take a heavy toll on productivity and development.
Living in a Water-Stressed World
A housing development lies on the edge of Cathedral City, a desert resort town in southern California, in April 2015.Damon Winter/New York Times/Redux
The COVID-19 pandemic heightened the need for safe water access. Handwashing is one of the most effective tools for combating the coronavirus, but health experts noted that three in ten individuals—2.3 billion people globally—could not wash their hands at home at the pandemic’s onset.
How has water factored into international relations?
Many freshwater sources transcend international borders, and, for the most part, national governments have been able to manage these resources cooperatively. Roughly three hundred international water agreements have been signed since 1948. Finland and Russia, for example, have long cooperated on water-management challenges, including floods, fisheries, and pollution. Water-sharing agreements have even persisted through cross-border conflicts about other issues, as has been the case with South Asia’s Indus River and the Jordan River in the Middle East.
However, there are a handful of hot spots where transboundary waters are a source of tension, either because there is no agreement in place or an existing water regime is disputed. One of these is the Nile Basin, where the White and Blue Nile Rivers flow from lakes in East Africa northward to the Mediterranean Sea. Egypt claims the rights to most of the Nile’s water based on several treaties, the first dating back to the colonial era; but other riparian states say they are not bound to the accords because they were never party to them. The dispute has flared in recent years after Ethiopia began construction of a massive hydroelectric dam that Egypt says drastically cuts its share of water.
Ethiopian Dam Ignites Tensions With Egypt, Sudan Over Nile Waters
Flow
direction
Cairo
Sources of Nile
River water in Egypt
EGYPT
Blue Nile: 57%
White Nile: 31%
Other: 12%
Lake
Nasser
RED
SEA
Nile
SUDAN
Khartoum
White Nile
Blue Nile
ETHIOPIA
SOUTH
SUDAN
Grand Ethiopian
Renaissance Dam
Lake Victoria
Sources: Mada Masr; UN Food and Agriculture Organization.
Transboundary water disputes can also fuel intrastate conflict; some observers note this has increased in recent years, particularly in the hot spots where there are fears of cross-border conflict. For example, a new hydropower project could benefit elites but do little to improve the well-being of the communities who rely on those resources.
Moreover, water stress can affect global flows of goods and people. For instance, wildfires and drought in 2010 wiped out Russian crops, which resulted in a spike in commodities prices and food riots in Egypt and Tunisia at the start of the Arab uprisings. Climate stress is also pushing some to migrate across borders. The United Nations predicts that without interventions in climate change, water scarcity in arid and semi-arid regions will displace hundreds of millions of people by 2030.
What are international organizations and governments doing to alleviate water stress?
There has been some international mobilization around water security. Ensuring the availability and sustainable management of water and sanitation for all is one of the UN Sustainable Development Goals (SDGs), a sweeping fifteen-year development agenda adopted by member states in 2015. Smart water management is also vital to many of the other SDGs, such as eliminating hunger and ensuring good health and well-being. And while the Paris Agreement on climate does not refer to water explicitly, the United Nations calls [PDF] water management an “essential component of nearly all the mitigation and adaptation strategies.” The organization warns of the increasing vulnerability of conventional water infrastructure, and points to many climate-focused alternatives, such as coastal reservoirs and solar-powered water systems.
However, there is no global framework for addressing water stress, like there is for fighting climate change or preserving biodiversity. The most recent UN summit on water, held in March 2023, was the first such conference since 1977 and didn’t aim to produce an international framework. It instead created a UN envoy on water and saw hundreds of governments, nonprofits, and businesses sign on to a voluntary Water Action Agenda, which analysts called an important but insufficient step compared to a binding agreement among world governments.
Some governments and partner organizations have made progress in increasing access to water services: Between 2000 and 2017, the number of people using safely managed drinking water and safely managed sanitation services rose by 10 percent and 17 percent, respectively. In 2022, the Joe Biden administration announced an action planto elevate global water security as a critical component of its efforts to achieve U.S. foreign policy objectives. But the pace of climate change and the COVID-19 pandemic have presented new challenges. Now, many countries say they are unlikely to implement integrated water management systems by 2030, the target date for fulfilling the SDGs.
Still, some governments are taking ambitious and creative steps to improve their water security that could serve as models for others:
Green infrastructure. Peruvian law mandates that water utilities reinvest a portion of their profits into green infrastructure (the use of plant, soil, and other natural systems to manage stormwater), and Canada and the United States have provided tens of millions of dollars in recent years to support Peru’s efforts [PDF]. Vietnam has taken similar steps to integrate natural and more traditional built water infrastructure.
Wastewater recycling. More and more cities around the globe are recycling sewage water into drinking water, something Namibia’s desert capital has been doing for decades. Facilities in countries including China and the United States turn byproducts from wastewater treatment into fertilizer.
Smarter agriculture. Innovations in areas such as artificial intelligence and genome editing are also driving progress. China has become a world leader in bioengineering crops to make them more productive and resilient.
Recommended Resources
The Wilson Center’s Lauren Risi writes that water wars between countries have not come to pass, but subnational conflicts over the resource are already taking a toll.
CFR’s Why It Matters podcast talks to Georgetown University’s Mark Giordano and the Global Water Policy Project’s Sandra Postel about water scarcity.
The World Economic Forum describes the growing water crisis in the Horn of Africa, while National Geographic looks at how the prolonged drought is pushing wildlife closer to towns.
The World Resources Institute’s Aqueduct maps the areas facing extremely high water stress.
The United Nations shares facts about water and its role in all aspects of life.
BuzzFeed News interviews residents of Jackson, Mississippi, who lost access to safe water after freezing temperatures wreaked havoc on the city’s decaying infrastructure.
World Water Day is held every year on 22 March to raise awareness of global freshwater challenges and solutions.
This year’s theme is Glacier Preservation, highlighting how their rapid melting threatens water security and livelihoods.
World Water Day is held every year on 22 March, and is a United Nations (UN) day focused on raising awareness of the importance of freshwater.
This year’s World Water Day theme, Glacier Preservation, highlights the urgent need to protect glaciers, as their rapid melting threatens water security, ecosystems and livelihoods, requiring collective global and local action.
“Glaciers may be shrinking, but we cannot shrink from our responsibilities … Action this year is critical. Every country must deliver strong national climate action plans aligned with limiting global temperature rise to 1.5 degrees Celsius,” reminds UN Secretary-General, António Guterres.
This year’s theme is Glacier Preservation. Image: United Nations
In 2021, more than 2 billion people lived in water-stressed countries. This is expected to be made worse as a result of climate change and population growth.
And so World Water Day has been observed since 1993 to highlight the work that remains to ensure everyone on Earth has access to clean drinking water. And while it’s a high-profile issue – check out our podcast with Matt Damon below – the figures above emphasize the challenges that remain, especially with freshwater usage increasing each year.
The World Health Organization warns that “historical rates of progress would need to double” for the world to achieve universal coverage of basic drinking water services by the end of the decade.
Only 0.5% of water on Earth is useable and available freshwater – and climate change is dangerously affecting that supply, says the World Meteorological Association. Over the past 20 years, terrestrial water storage – including soil moisture, snow and ice – has dropped at a rate of 1cm per year, with major ramifications for water security.
Natural resource shortages, including water insecurity, is a major risk over the next decade. Image: World Economic Forum
From climate change to urbanization and demographic changes, water supply systems face numerous risks. Indeed, the World Economic Forum’s Global Risks Report 2025lists “natural resource shortages” as the 4th biggest risk over the next decade.
That’s why raising awareness on conserving and protecting freshwater for everyone on Earth is vital, especially as the world looks to find – and implement – solutions.
Water and climate change are inextricably linked, with glaciers playing a critical role in maintaining freshwater availability. Rising global temperatures are accelerating glacial melt, disrupting the seasonal flow of meltwater that feeds major river systems. These rivers support agriculture, drinking water supply, and hydropower for millions of people, particularly in lowland regions.
As glaciers recede, water sources become less predictable, leading to prolonged droughts, reduced soil moisture, and declining groundwater levels. At the same time, excessive glacial melting can contribute to flooding, landslides and glacial lake outburst floods, endangering communities and infrastructure. These disruptions affect ecosystems, food security and livelihoods, making glacial melt a key driver of water-related challenges in a changing climate.
Find out more about the challenges in the session below from our Annual Meeting in 2024 –Out of Balance with Water.
Innovation to help improve water security
Innovation and entrepreneurial thinking can also help conserve and protect freshwater sources. The World Economic Forum’s UpLink platform supports purpose-driven entrepreneurs by building ecosystems to help scale their businesses, focusing on solutions for global challenges such as climate change, ecosystem degradation and inequality.
One of its Top Innovators is a Latin American Climatech company connecting farmers seeking to improve irrigation practices with companies focused on water security. Kilimo implements measurable, auditable actions that deliver water volumetric benefits through partnerships between farmers and companies. With this business model, it aims to promote climate adaptation and ensure water availability for communities, ecosystems and economic development.
Meanwhile, the video below shows how sustainable water management practices, including conservation techniques like Ice Stupas and Glacial Grafting, can help mitigate some of these challenges by supporting water storage and availability in vulnerable regions.
Collaboration between public and private sectors has a significant role to play in providing clean water for all, and ensuring a sustainable, resilient global water system. The Forum’s Water Futures Community is a collaborative platform driving solutions and finance to address emerging water challenges, advancing the global water agenda through dialogue and partnerships.
Nairobi, 28 August 2024 – In half the world’s countries one or more types of freshwater ecosystems are degraded, including rivers, lakes and aquifers. River flow has significantly decreased, surface water bodies are shrinking or being lost, ambient water is growing more polluted, and water management is off-track. These are some of the findings of three reports tracking progress on freshwater, published today by UN-Water and the UN Environment Programme (UNEP).
The triennial series of reports is focused on progress towards achieving the goal of “clean water and sanitation for all” (SDG 6) through protecting and restoring freshwater sources. Based on greater data sets than ever before, the reports reiterate the call to scale up support for Member States in tackling challenges through the UN System-wide strategy for water and sanitation and the accompanying upcoming Collaborative Implementation Plan.
“Our blue planet is being rapidly deprived of healthy freshwater bodies and resources, with dire prospects for food security, climate change and biodiversity,” said Dianna Kopansky, Head of the Freshwater and Wetlands Unit, Ecosystems Division at UNEP. “At this critical point, global political commitments for sustainable water management have never been higher, including through the passing of a water resolution at the last UN Environment Assembly in February, but they are not being matched by required finance or action. Protection and restoration policies, tailored for different regions, are halting further loss and show that reversing degradation is within reach. We absolutely need more of them.”
Widespread degradation
A reported 90 countries, most in Africa, Central- and Southeast Asia, are experiencing the degradation of one or more freshwater ecosystems. Other regions, such as Oceania, mark improvements. Pollution, dams, land conversion, over-abstraction and climate change contribute to degradation of freshwater ecosystems.
Influenced by climate change and land use, river flow has decreased in 402 basins worldwide – a fivefold increase since 2000. A much smaller number is gaining in river flow.
Loss of mangroves due to human activities (e.g., aquaculture and agriculture) poses a risk to coastal communities, freshwater resources, biodiversity, and climate due to their water filtration and carbon sequestering properties. Significant decreases of mangroves were reported in Southeast Asia, though the overall net rate of deforestation has leveled off in the last decade.
Lakes and other surface water bodies are shrinking or being lost entirely in 364 basins worldwide. A continued high level of particles and nutrients in many large lakes can lead to algal blooms and low-oxygen waters, primarily caused by land clearance and urbanization, and certain weather events.
Nevertheless, the construction of reservoirs contributes to a global net-gain in permanent water, mainly in regions like North America, Europe, and Asia.
Low levels of water quality monitoring
The poorest half of the world contributes under 3 per cent of global water quality data points, including only 4,500 lake quality measurements out of almost 250,000. This reveals an urgent need to improve monitoring capacity.
Lack of data on this scale means that by 2030 over half of humanity will live in countries that have inadequate water quality data to inform management decisions related to address drought, floods, impacts from wastewater effluents and agricultural runoff.
Where good data are available, it shows that freshwater quality has been degrading since 2017. Where data are lacking, the signs are not promising.
Report authors recommend the expansion and development of routine government-funded monitoring programmes, as well as incorporating citizen science into such national programmes, and exploring the potential of satellite-based Earth observation and modelled data products to help fill the data gap.
Inadequate progress on water resources management in over 100 countries
Balancing competing needs for sustainable water use from society and the economy requires the implementation of integrated water resources management (IWRM) across sectors, at all levels and across borders by 2030.
47 countries have fully reached or almost reached IWRM, 63 countries need to accelerate implementation, while 73 countries have only limited capacity for IWRM. At the current rate of reported progress, the world will only achieve sustainable water management by 2049. This means that by 2030 at least 3.3 billion people in over 100 countries are likely to have ineffective governance frameworks to balance competing water demands.
Solutions include unlocking finance through revenue raising and cost recovery arrangements, investments in infrastructure and management, as well as coordinated action, greater institutional capacity and better monitoring networks.
NOTES TO EDITORS
About the UN Environment Programme (UNEP) UNEP is the leading global voice on the environment. It provides leadership and encourages partnership in caring for the environment by inspiring, informing and enabling nations and peoples to improve their quality of life without compromising that of future generations.
About UN-Water UN-Water coordinates the UN’s work on water and sanitation. It is comprised of UN Members States and international organizations working on water and sanitation issues. UN-Water’s role is to ensure that Members and Partners ‘deliver as one’ in response to water-related challenges.
GET WET! 