Lava flows have grown more vigorous in recent days and there's concern more homes may burn and more evacuations may be ordered. Still, scientists can't say whether lava flows from nearly two dozen fissures will continue to advance, or stop.

"We have no way of knowing whether this is really the beginning or toward the end of this eruption," said Tom Shea, a volcanologist at the University of Hawaii. "We're kind of all right now in this world of uncertainty."

In addition to ash fallout from explosions and the threat of lava crossing main highways, officials warned of another hazard Saturday as a flow advanced southeast to the ocean: Laze.

"Laze is when hot lava hits the ocean sending hydrochloric acid and steam with fine glass particles in the air," the Hawaii County Civil Defense agency said in an update to the public.

The area affected by lava and ash is small compared to the Big Island, which is about 4,000 square miles (10,360 square kilometers). Most of the island and the rest of the Hawaiian chain is unaffected by the volcanic activity on Kilauea.

State and local officials have been reminding tourists that flights in and out of the entire state, including the Big Island, have not been impacted. Even on the Big Island, most tourist activities are still available and businesses are open.

Evacuation orders for two neighborhoods with nearly 2,000 people were given after a first fissure opened on May 3. Officials have been warning neighboring communities to be prepared to evacuate.

A handful of people were trapped when a flow crossed a road Friday. Some had to be airlifted to safety.

"They shouldn't be in that area," said County Managing Director Wil Okabe.

Lava flows have become faster as fresher magma mixed with decades-old magma.

The change is attributed to new magma mixing with 1955-era magma in the ground, creating hotter and more fluid flows, scientists said.

By Saturday morning, two of 22 fissures had merged, creating a wide flow advancing at rates of up to 300 yards (274 meters) per hour. Aerial footage from the USGS showed fast-moving lava advancing to the southeast. The flow was 1.5 miles (2.4 kilometers) from the ocean, scientists said.

In the background, the footage showed lava fountaining 328 feet (100 meters) high at one of the fissures. The fountains are created by vents closing, forcing magma to burst through a single outpoint, Stovall said.

Civil Defense Administrator Talmadge Magno said a man suffered a "serious" leg injury Saturday when he was hit with a lava spatter while sitting on his porch near the Lanipuna Garden subdivision, the Star-Advertiser reported.

Edwin Montoya, who lives with his daughter on her farm near the site where lava crossed the road and cut off access, said the fissure opened and grew quickly.

"It was just a little crack in the ground, with a little lava coming out," he said. "Now it's a big crater that opened up where the small little crack in the ground was."

The Big Island volcano released a small explosion at its summit just before midnight Friday, sending an ash cloud 10,000 feet (3,048 meters) into the sky. The USGS's Hawaiian Volcano Observatory said eruptions that create even minor amounts of ashfall could occur at any time.

This follows the more explosive eruption Thursday, which emitted ash and rocks thousands of feet into the sky. No one was injured and there were no reports of damaged property.

It came two weeks after the volcano began sending lava flows into neighborhoods 25 miles (40 kilometers) to the east of the summit.

Hawaii County Civil Defense said a fissure near the neighborhood of Lanipuna Gardens has been continuously erupting, releasing a slow-moving lava flow. If that lava threatens a nearby highway, more people will be told to prepare for voluntary evacuation.

On Friday, fast-moving lava crossed a road and isolated about 40 homes in a rural subdivision, forcing at least four people to be evacuated by county and National Guard helicopters.

The wide lava flow was "very active" Saturday morning and advancing at rates of up to 300 yards (274 meters) per hour, scientists from the Hawaiian Volcano Observatory said.

Police, firefighters and National Guard troops were securing the area of the Big Island and stopping people from entering, Hawaii County Civil Defense reported. The homes were isolated in the area east of Lanipuna Gardens and Leilani Estates. Both neighborhoods had 40 structures, including 26 homes, decimated by lava over the past two weeks.

Three people still in that area Friday night were initially advised to shelter in place and await rescue by helicopter first thing Saturday. Since then, two of them got out on their own in the morning and one was evacuated by air, said Janet Snyder, spokeswoman for Hawaii County.

"They shouldn't be in that area. We told them they will be locked in," said County Managing Director Wil Okabe. "It's more serious now. They're putting their lives at risk."

He said he hopes people heed evacuation warnings.

County officials have been encouraging residents in other parts of the district to prepare for potential evacuations.

Edwin Montoya, who lives with his daughter on her farm near the site where lava crossed the road and cut off access, said he was at the property earlier in the day to get valuables.

"I think I'm lucky because we went there this morning and we got all the batteries out, and all the solar panels out, about $4,000 worth of equipment," he said. "They have to evacuate the people that are trapped up there right now in the same place that we were taking pictures this morning."

He said no one was on his property, but his neighbor had someone on his land.

"I know that the farm right next to my farm . he's got somebody there taking care of the premises, I know he's trapped," Montoya said.

Montoya said the fissure that poured lava across the road opened and grew quickly.

"It was just a little crack in the ground, with a little lava coming out," he said. "Now it's a big crater that opened up where the small little crack in the ground was."

Experts are uncertain about when the volcano will calm down.

The Big Island volcano released a small explosion at its summit just before midnight Saturday, sending an ash cloud 10,000 feet (3,048 meters) into the sky. The U.S. Geological Survey's Hawaiian Volcano Observatory said eruptions that create even minor amounts of ashfall could occur at any time.

This follows the more explosive eruption Thursday, which emitted ash and rocks thousands of feet into the sky. No one was injured and there were no reports of damaged property.

Scientists said the eruption was the most powerful in recent days, though it probably lasted only a few minutes.

It came two weeks after the volcano began sending lava flows into neighborhoods 25 miles (40 kilometers) to the east of the summit.

A new lava vent—the 22nd such fissure—was reported Friday by county civil defense officials.

Several open fissure vents are still producing lava splatter and flow in evacuated areas. Gas is also pouring from the vents, cloaking homes and trees in smoke.

The fresher, hotter magma will allow faster lava flows that can potentially cover more area, said Janet Babb, a geologist with the Hawaiian Volcano Observatory.

Much of the lava that has emerged so far may have been underground for decades, perhaps since a 1955 eruption.

Meanwhile, more explosive eruptions from the summit are possible.

"We have no way of knowing whether this is really the beginning or toward the end of this eruption," said Tom Shea, a volcanologist at the University of Hawaii. "We're kind of all right now in this world of uncertainty."

It's nearly impossible to determine when a volcano will stop erupting, "because the processes driving that fall below the surface and we can't see them." said volcanologist Janine Krippner of Concord University in West Virginia.

U.S. government scientists, however, are trying to pin down those signals "so we have a little better warning," said Wendy Stovall, a volcanologist with the observatory.

Thus far, Krippner noted, authorities have been able to forecast volcanic activity early enough to usher people to safety.

The greatest ongoing hazard stems from the lava flows and the hot, toxic gases spewing from open fissure vents close to homes and critical infrastructure, said Charles Mandeville of the U.S. Geological Survey's volcano hazards program.

Authorities have been measuring gases, including sulfur dioxide, rising in little puffs from open vents.

The area affected by lava and ash is small compared to the Big Island, which is about 4,000 square miles. Most of the island and the rest of the Hawaiian chain is unaffected by the volcanic activity on Kilauea.

State and local officials have been reminding tourists that flights in and out of the entire state, including the Big Island, have not been impacted. Even on the Big Island, most tourist activities are still available and businesses are open.

Columbia University Professor Jeffrey Sachs said the world's ways of producing and using energy need to change "much faster, much more dramatically" than political leaders looking to tap hydrocarbon reserves understand.

"So, if we want to move to zero emissions we better get the idea to move away from fossil fuels faster than Shell oil company thinks we can," Sachs told a conference in the Cypriot capital on the climate change challenges faced by Mediterranean countries and the Middle East.

Sachs said climate change bringing desertification, drought, crop failures and rising sea levels are putting the region's agriculture "in dire threat."

"It's worked well for the last 8,000 years and we're going to ruin it in this generation, and that's crazy," said Sachs, who also serves as an adviser to United Nations Secretary-General Antonio Guterres on sustainable development.

"This is the tinder of conflict, of mass migration, or all the things we don't handle decently," he added.

Sachs says the best approach is to set up interconnected power grids where emissions-free electricity from renewable energy sources in one region could be transmitted elsewhere.

For instance, an interconnected grid would enable North African and the Middle Eastern countries harnessing their ample solar power potential to transmit generated electricity to colder and less sunny northern Europe.

Sachs hailed China as the current world leader in the energy interconnection project and urged Europe to draw up similar plans.

Although opposing exploitation of east Mediterranean gas deposits, he urged countries moving ahead with such projects to take steps and steeply curb carbon emissions while preparing their economies for carbon-free electricity generation to fire up everything from cars, to ships and factories.

Sachs, who also heads Columbia University's Earth Institute, said Mediterranean countries could work together to draw up proposals on mitigating the challenges they face and submit them to a high-level U.N. climate summit set for September, 2019.

Hawaii County Civil Defense said police, firefighters and National Guard troops were securing the area of the Big Island and stopping people from entering.

The homes were isolated in the area east of Leilani Estates and Lanipuna Gardens—two neighborhoods where lava has destroyed 40 structures, including 26 homes, over the past two weeks.

Officials were assessing how many people were still in the newly threatened area. They were advising people to shelter in place and await further instructions.

County officials have been encouraging residents in the district to prepare for potential evacuations.

Edwin Montoya, who lives with his daughter on her farm near the site where lava crossed the road and cut off access, said he was at the property earlier in the day to get valuables.

"I think I'm lucky because we went there this morning and we got all the batteries out, and all the solar panels out, about $4,000 worth of equipment," he said. "They have to evacuate the people that are trapped up there right now in the same place that we were taking pictures this morning."

He said no one was on his property, but his neighbor had someone on his land.

"I know that the farm right next to my farm . he's got somebody there taking care of the premises, I know he's trapped," Montoya said.

Montoya said the fissure that poured lava across the road opened and grew quickly.

"It was just a little crack in the ground, with a little lava coming out," he said. "Now it's a big crater that opened up where the small little crack in the ground was."

Experts are uncertain about when the volcano will calm down.

The Big Island volcano had an explosive eruption at its summit Thursday, sending ash and rocks thousands of feet into the sky. No one was injured and there were no reports of damaged property.

Scientists said the eruption was the most powerful in recent days, though it probably lasted only a few minutes.

It came two weeks after the volcano began sending lava flows into neighborhoods 25 miles (40 kilometers) to the east of the summit.

A new lava vent—the 22nd such fissure—was reported Friday by county civil defense officials.

Several open fissure vents are still producing lava splatter and flow in evacuated areas. Gas is also pouring from the vents, cloaking homes and trees in smoke.

The fresher, hotter magma will allow faster lava flows that can potentially cover more area, said Janet Babb, a geologist with the Hawaiian Volcano Observatory.

Much of the lava that has emerged so far may have been underground for decades, perhaps since a 1955 eruption.

Meanwhile, more explosive eruptions from the summit are possible.

"We have no way of knowing whether this is really the beginning or toward the end of this eruption," said Tom Shea, a volcanologist at the University of Hawaii. "We're kind of all right now in this world of uncertainty."

It's nearly impossible to determine when a volcano will stop erupting, "because the processes driving that fall below the surface and we can't see them." said volcanologist Janine Krippner of Concord University in West Virginia.

U.S. government scientists, however, are trying to pin down those signals "so we have a little better warning," said Wendy Stovall, a volcanologist with the observatory.

Thus far, Krippner noted, authorities have been able to forecast volcanic activity early enough to usher people to safety.

The greatest ongoing hazard stems from the lava flows and the hot, toxic gases spewing from open fissure vents close to homes and critical infrastructure, said Charles Mandeville of the U.S. Geological Survey's volcano hazards program.

Authorities have been measuring gases, including sulfur dioxide, rising in little puffs from open vents.

The area affected by lava and ash is small compared to the Big Island, which is about 4,000 square miles. Most of the Big Island and the rest of the state's island chain is unaffected by the volcanic activity on Kilauea.

State and local officials have been reminding tourists that flights in and out of the Big Island and the rest of the of the state have not been impacted. Even on the Big Island, most tourist activities are still available and businesses are open.

The Kilauea volcano exploded at its summit shortly after 4 a.m. Thursday following two weeks of volcanic activity that sent lava flows into neighborhoods and destroyed at least 26 homes. Scientists said the eruption was the most powerful in recent days, though it probably lasted only a few minutes.

And it had a smell.

"This morning it smelled like sulfur so we had to close all the windows," Lindsey Magnani said Thursday as she and her family picked up masks in Volcano, Hawaii. She and her fiance, Elroy Rodrigues, had been sneezing all day, but their children—Kahele Rodrigues, 2, and Kayden Rodrigues, 3 months old—were doing OK.

Authorities handed out around 2,000 masks for protection for people living near the volcano. But geologists have warned that the volcano could become even more violent, with increasing ash production and the potential that future blasts could hurl boulders the size of cows from the summit.

But after Thursday's eruption, most residents found only thin coatings of ash, if they saw any at all, as winds blew much of the 30,000-foot (9,100-meter) plume away from people.

"It was a grit, like a sand at the beach," said Joe Laceby, who lives in Volcano a few miles to the northeast of Kilauea's summit. The ash was a bit of an irritant, he said, but "not too bad."

Laceby sealed windows and cracks in his home with cellophane wrap to keep out ash and volcanic gases. He has gas masks to protect himself from the toxic fumes and ash.

Winds kept the ash away from the Volcano Winery, tasting room manager Lani Delapenia said. A thin coating of white soot had blanketed tables and vines the day before, on Wednesday, but none wafted over the day of the 30,000-foot plume. The strength and direction of the wind makes all the difference, she said.

"The Volcano Village, and us at the winery, are doing well and we hope people still come and visit us and order wine because we are still pumping wine out," Delapenia said.

The vineyard also has a great view of the plume, she said.

Julia Neal, operator of Pahala Plantation Cottages about 28 miles (45 kilometers) southwest of the summit crater, said people have been picking up ash masks from county civil defense workers at the local community center. Some people working outside were wearing them. People with asthma were staying inside, she said.

The eruption reminded her of 2008, when Kilauea also had large summit eruptions and sent ash and gas over her community.

A light dusting fell Thursday, but the town had more ash a couple of days ago when people had to wash it off their cars, she said.

"People are renovating one of the historic buildings across the street. The school kids just stopped by. They're getting ready to graduate. Life is going on quite vibrantly here with people taking these precautions," she said.

The National Weather Service issued an ash advisory and then extended it through early evening, and county officials distributed ash masks to area residents. Several schools closed because of the risk of elevated levels of sulfur dioxide, a volcanic gas.

Dr. Josh Green, a state senator who represents part of the Big Island, said the immediate risk health risk comes from ash particles in the air. Anyone with respiratory difficulties, such as asthma or emphysema, should limit exposure to the ash, he said.

The Federal Aviation Administration extended a restriction on aircraft from entering the airspace up to 30,000 feet above sea level. The earlier limit was up to 10,000 feet (3,000 meters). The prohibition applies to a 5-mile (8-kilometer) radius around the crater.

Thursday's eruption did not affect the Big Island's two largest airports in Hilo and in Kailua-Kona.

The crater spewing ash sits within Hawaii Volcanoes National Park, which has been closed since May 11 as a safety precaution over risks of a violent eruption.

Scientists warned May 9 that a drop in the lava lake at the summit might create conditions for a large explosion. Geologists predicted such a blast would mostly release trapped steam from flash-heated groundwater.

Kilauea has also been erupting lava into neighborhoods 25 miles (40 kilometers) to the east of the summit crater since May 3. County civil defense officials on Friday reported a new lava vent in the area—the 22nd such fissure.

Kilauea, one of the world's most active volcanoes, has been erupting continuously since 1983. It's among the five volcanoes that form the Big Island, and it's the only one actively erupting. In 1924, an eruption killed one person and sent rocks, ash and dust into the air for 17 days.

Geologists with the University of Cincinnati examined drinking water in Carroll, Stark and Harrison counties, a rural region in northeast Ohio where many residents rely on water from private underground wells.

The time-series study was the first of its kind in Ohio to examine methane in groundwater in relation to natural gas drilling. The results were published in the journal Environmental Monitoring and Assessment.

"Some people had elevated concentrations of methane in their groundwater, but the isotopic composition showed it wasn't from natural gas" said Amy Townsend-Small, associate professor of geology in UC's McMicken College of Arts and Sciences.

"What we found is in most cases it was probably from underground coal in the area or biological methane produced in groundwater."

UC researchers collected 180 groundwater samples in total at homes in the three counties. Some of the sites were sampled multiple times. In particular, researchers looked for evidence of methane, the primary compound in natural gas. They also studied changes in the acidity or pH of the water, and changes to its conductivity.

They found no increase in methane concentration or composition in groundwater over the four years of the study, despite the presence of new shale gas wells drilled in the study area. Likewise, they did not find higher methane levels in closer approximation to shale drilling.

Researchers did find wide variability in methane concentrations in the drinking water, ranging from 0.2 micrograms per liter to 25.3 milligrams per liter, which is strong enough to catch fire in enclosed spaces. But researchers found no relationship between the methane observed in drinking water and the new gas wells.

"Clearly, additional monitoring is needed to determine whether methane concentrations and source signals in this region change as the number of oil and gas wells continues to increase," the study concluded.

Researchers identified the chemical composition of the water using gas chromatography, isotope ratio mass spectrometry, and radiocarbon dating in a UC geology lab. Understanding the chemical composition helps identify the source of methane found in drinking water: from natural gas extraction, organic decomposition or even from the digestive systems of nearby cows.

Lead author and UC graduate Claire Botner said the study solicited participation by homeowners who were willing to let researchers test their wells.

The study area has seen increasing interest from natural gas companies in recent years. It's located above a geological feature called the Utica Shale formation, which is known to harbor oil and natural gas. When UC launched its methane study in 2012, Ohio had issued 115 drilling permits for the region. By the study's end in 2015, nearly 1,600 permits had been issued, primarily for Carroll County.

Hydraulic fracturing is a process by which pressurized water, sand and chemicals are pumped into natural-gas wells more than a mile deep to break apart shale to release pockets of oil and natural gas.

Researchers hypothesized that methane concentrations in the drinking-water wells they sampled would increase over time with the growth of natural gas drilling in the area. This is a correlation researchers observed in Pennsylvania's Marcellus Shale region.

But that's not what UC's water tests revealed. The study concluded that methane observed in groundwater was "biogenic," or naturally occurring and independent of natural gas drilling.

"The study researchers in Pennsylvania thought the contamination issue was a failure of the well casings in the fracking wells," Townsend-Small said.

"Hopefully, that doesn't happen often. And that apparently didn't happen with the wells of homeowners we worked with for our study."

Townsend-Small has spent much of her career researching groundwater and methane. She and other UC geologists are studying the influence of the Great Miami River on groundwater in southwest Ohio at UC's C.V. Theis Groundwater Observatory. She also has studied atmospheric methane in relation to algae blooms in the Great Lakes and methane in arctic lakes in Alaska.

"Some people had elevated concentrations of methane in their groundwater, but the isotopic composition showed it wasn't from natural gas. It was from a different source," Townsend-Small said. "What we found is in most cases it was probably from underground coal in the area or biological methane produced in groundwater."

Study co-authors included UC professor emeritus David Nash and UC assistant professor of geology Joshua Miller.

Botner said if researchers were to replicate the study, she might recommend expanding it to include other hydrocarbons such as propane or look for carbonate isotopes associated with natural gas drilling.

"It's a controversial topic," Botner said. "But that's why science is so valuable. Maybe another study would confirm our findings or maybe they would find something else. Regardless, we would welcome more well testing."

Carroll County Commissioner Robert Wirkner said the findings were good news for residents. Like many of his neighbors, he gets drinking water at his house from a private well on his property.

Wirkner said gas companies test the drinking water of nearby homes before and after they drill a well to observe any changes in water quality.

"My water has been tested multiple times," he said. "So we're happy to hear the findings."

Townsend-Small said protecting wells from contamination is especially important in rural areas because there are few alternatives for clean drinking water. Digging a new or deeper well is expensive and would not necessarily solve a pollution problem. And there are few opportunities in rural areas to connect to public water lines.

"It would be great if homeowners had access to ongoing monitoring," she said. "In cities, you are reassured that your drinking water is safe. We pay the public water utilities to test the water every day. But if you have a private well, you just have to hope that it's not contaminated on a day-to-day basis."

More information:
E. Claire Botner et al, Monitoring concentration and isotopic composition of methane in groundwater in the Utica Shale hydraulic fracturing region of Ohio, Environmental Monitoring and Assessment (2018). DOI: 10.1007/s10661-018-6696-1

Rustem Amirov was alone on the 8,516 metre (27,940 feet) mountain, which neighbours Mount Everest, when he died of altitude related complications on Thursday.

"He was climbing solo without any guides with him. The body has not been brought down to the base camp yet," Gyanendra Shrestha, a government liaison officer at Everest base camp, told AFP.

Climbers attempting Lhotse use the same base camp as those aiming for Everest's summit.

They follow the same route up the mountain, scaling the sheer Lhotse Face—a 1,125 metre wall of ice—before the path to the neighbouring summits divides.

Amirov, an experienced climber who had previously led an expedition on the 8,201 metre Cho Oyu peak—also in the Nepali Himalaya—only arrived at Everest base camp in early May, according to his Facebook page.

Most climbers arrive in April and spend at least a month acclimatising to the harsh, low oxygen environment.

Altitudes above 8,000 metres are known as the "death zone" among climbers. The air contains less than a third of the oxygen at sea level and humans cannot survive at those heights for long.

Deprived of oxygen, fluid builds up on the lungs and brain, which is fatal if climbers do not reach a lower altitude in time.

Most climbers use bottled oxygen to reduce the effects of high altitude. It was not clear if Amirov was climbing with supplemental oxygen.

A post on Amirov's Facebook page said that a rescue team was sent but failed to reach him in time.

"High altitude porters were sent to rescue him, and help him down to camp two. Unfortunately it was too late. He was unconscious when he passed away," the post said.

Hundreds of climbers are attempting to reach the summit of Everest during the April-May climbing season. Just a few dozen are aiming for the top of Lhotse.

Nepal is home to eight of the world's 14 highest peaks and foreign climbers that flock to its mountains are a major source of revenue for the country.

The rapid growth of the climbing industry has created sharp competition among companies for business, but also led to fears that some are skimping on safety measures for climbing at extreme altitudes.

Ethnic Sherpas from the valleys around Everest have become synonymous with high altitude climbing.

With their unique ability to work in a low-oxygen, high altitude atmosphere, they are the backbone of the industry, hauling clients and equipment to the top of the 8,848-metre (29,029-foot) mountain.

The number of Everest climbers has more than doubled in two decades, however, and the Sherpa supply has not kept pace. Raw recruits are now being used to reach the top and it has already taken a toll.

Dawa Sange Sherpa, 20, summited Mount Everest last year—a first for him and the climber he was with.

On the way down, the cold, lack of oxygen and exhaustion took hold. The pair collapsed just below the summit and were found hours later, barely alive.

"My friend said to me, 'He's done'. But I found a small pulse in him," said guide Ang Tshering Lama, who found Sange.

Everest victim

Lama dragged the unconscious Sange back down the mountain while others helped his client.

Both had severe frostbite. Sange lost all of his fingers, spelling the end of his short career on Everest.

Sange was not meant to be guiding that year. He was planned to be carrying equipment up the mountain, a job many young Sherpa do before graduating to become guide.

"I was in the second team, in which untrained Sherpa usually carry the equipment and food from the base camp to camp two, three and four," Sange said.

But his employer, Seven Summit Treks, the largest Nepal-based expedition operator, had more than 60 clients on Everest and needed someone to take a paying climber to the top.

Head of Seven Summit Treks Mingma Sherpa said Sange was ready to be a guide and had previously summited Everest. Sange said he had not.

Nine other Sherpa from Seven Summit Treks were rescued on Everest that year, but Mingma denied there were any problems.

"A Sherpa can summit five times, eight times but sometimes he gets a problem. That's the body," he said.

With the climbing season barely started, so far this year at least four Sherpas from Seven Summit Treks have already sustained frostbite, according to base camp sources.

'Risky business'

No qualifications are needed to work on Everest. Some expedition operators require staff to do one of two short courses for mountain workers. Others do not.

Mingma dismissed the Nepal Mountaineering Association courses as worthless, saying everything could be learned on the mountain.

"My Sherpa don't have any training with NMA. NMA training for us is not enough, we should do our own training on the mountain," he said.

Dawa Steven Sherpa of Asian Trekking requires all staff to have done the NMA course. He said that budget expedition operators hire inexperienced Sherpa to cut costs.

"As long as his name is Sherpa," he quipped of the recruitment criteria.

Experienced Sherpa guides can make up to $10,000 in the April to May climbing season, more than 14 times Nepal's average annual income. The lowest paid will barely scrape together $1,000 for two months' risky work.

"It's the fault of the clients as well if they just close their eyes and go cheap," said Lama, who rescued Sange.

Seven Summit Treks—which charges about $20,000 to climb Everest, less than a third of other operators—blames rivals for the shortage, accusing them of not investing in the next generation of Sherpa guides.

"They take only experienced Sherpas. They don't want to spend extra money to train new Sherpas," Mingma said.

Phurba Tashi Sherpa, head Sherpa with the Himalayan Experience company, who has summited Everest 21 times, said it was becoming more difficult to find experienced Sherpa for his team.

"The young Sherpa are very strong and they think they can do everything, but actually they can't. The older Sherpa go slow and steady," he said.

Sherpa have been helping Everest climbers since the first British teams set their sights on the summit in the 1920s.

Their unique physiology, adapted over thousands of years of living at high altitudes, has made them essential since. A recent British study found that Sherpas use oxygen more efficiently than lowlanders.

But climbing Sherpa have arguably become a victim of their own success, and the community is now at a generational turning point.

Many experienced Sherpa who started working for the first commercial expeditions in the 1990s are retiring. Others have left Nepal for rival mountaineering countries buoyed by their reputation for being strong and dedicated.

They have earned enough money to educate their children in Kathmandu, or even in India and the United States.

"They are educated so they can find other jobs," said Kami Rita Sherpa, who has been guiding on Everest since 1994 and admits he would never allow his son to work in such a "risky business".

"If the old climbing guides don't bring their kids into this sector, the number of climbing Sherpas will definitely decline," he continued.

"Those from the next generation won't join this field."

The overall volume of coral in Sekisei Lagoon in southwestern Japan near Okinawa had already plunged by 80 percent since the late 1980s due to rising water temperatures and damage caused by coral-eating starfish.

Now only 1.4 percent of the lagoon, which stretches over 67.89 square kilometres, is in a healthy condition, the environment ministry said, after it was hit by mass bleaching in 1998, 2001, 2007 and most recently 2016.

"If coral reefs don't recover, it means a loss of rich fauna for a variety of creatures and would have grave impact on the ecosystem in the region," ministry official Chihiro Kondo told AFP on Friday.

For the first time since 2008, the ministry analysed satellite photos and information from some 1,000 monitoring sites for the Sekisei Lagoon and two other reefs around the Ishigaki and Iriomote islets in Okinawa.

The ratio of healthy corals stood at 14.6 percent in 1991 but dropped to 0.8 percent in the 2008 survey, Kondo said.

Two other neighbouring lagoons had similar results with the ratio of healthy areas around one percent.

Bleaching occurs when abnormal environmental conditions, such as warmer sea temperatures, cause corals to expel tiny photosynthetic algae, draining them of their colour.

Corals can recover if the water temperature drops and the algae are able to recolonise them.

"But the latest study shows that corals haven't recovered much since 2008, presumably partly because of the 2016 bleach," Kondo said.

One of the worst mass bleaching episodes on record took place in 1998 when the El Nino phenomenon was exceptionally strong, affecting reefs in 60 tropical countries.

Coral reefs are also under pressure from ocean acidification linked to CO2 emissions, scientists warn.

Corals make up less than one percent of Earth's marine environment, but are home to more than 25 percent of marine life.

As soon as one of the unmanned aerial vehicles spots suspicious smoke rising from a rooftop, a second one follows up to "sniff" for pollutants with its chemical sensors.

Ground-based operators then send police officers to knock on the door of the offending home to see if they are burning poor quality coal, plastic bottles or some other substance.

"Most people decide to pay a fine immediately rather than go to court," Katowice police spokesman Jacek Pytel told AFP, adding that fines can be up to 120 euros ($148).

From coal-fired power plants in Europe's east or car-clogged highways in the west, the European Union has for years struggled to enforce even the relatively modest pollution limits it has set.

Perhaps tellingly, at EU headquarters in Brussels, the air quality monitor on the busy road between the European Commission and the European Council buildings was recently not working for several months, according to activist group ClientEarth.

The four-lane highway separating the two main EU institutions is one of the most polluted in Brussels and has been at the centre of legal action launched by the NGO and five local residents, ClientEarth said.

"Citizens and organisations have a right to clean air," ClientEarth lawyer Ugo Taddei told AFP.

"We have achieved successes in the UK, German, Italian, French and Czech courts, with national judges ordering the adoption of more effective air quality plans and the introduction of restrictions on diesel vehicles."

'When the smog comes'

The key issue however is not so much the pollution limits themselves, but rather what action European countries propose to tackle a scourge that claims hundreds of thousands of lives a year.

The nitrogen dioxide belched by diesel cars, the curse of big cities, is to blame for 75,000 premature deaths a year, according to figures published last year by the European Environment Agency (EEA).

The scourge hits Europe's biggest economies particularly hard, causing 17,000 deaths per year in Italy, 14,000 in Britain, 12,800 in Germany and 9,300 in France, it said.

But the most dangerous substance is tiny particulate matter (PM2.5), which measures a fraction of a human hair in diameter and is responsible for nearly 400,000 premature deaths a year, the EEA said.

These break down to 66,000 in Germany, 60,000 in Italy and 46,000 in Poland, 35,000 in France and 37,600 in Britain.

In Katowice, Marian Kramarczyk, an 89-year-old with heart trouble, struggles in the polluted air.

"When the smog comes, I feel bad. I sneeze, I cough and my heart starts beating faster," Kramarczyk said.

The main culprit in all this is "the coal culture" which is considered "Poland's black gold," according to Patryk Bialas, who heads the city's anti-smog group, Alarm Smogowy.

The World Health Organization (WHO) says air pollution is to blame for around one third of global deaths linked to lung cancer. The same goes for cardiovascular disease.

For a long time, poor air quality was seen as an environmental issue but now it is "clearly" viewed as a health problem, WHO official Maria Neira told a conference in Brussels in February.

'Toxic bloc'

"In Shanghai, Beijing, New Delhi people feel it. Here it might be more invisible," Neira said.

Despite detailed legislation, the EU is struggling to enforce anti-pollution standards.

On the European Commission's desk lie some 33 cases of suspected breaches of air quality standards concerning 23 of the 28 member states and more than 130 cities.

Most of the cases concern small PM10 particles, which are only slightly larger than the PM2.5.

Two member states—Poland and Bulgaria—have already been taken to task by the EU's top court, the European Court of Justice, for having not only exceeded limits but having failed to propose immediate remedies.

On Thursday, the commission took Germany, Britain, France and Italy—the bloc's four largest economies—as well as Hungary and Romania to the top court for failing to apply long-sought steps to fix air quality.

"We cannot wait any longer," EU environment commissioner Karmenu Vella said after calling the problem "life threatening."

Germany, Britain and France were targeted for failing to meet limits on nitrogen dioxide while Italy, Hungary and Romania exceeded limits on particulate matter.

But the commission spared, at least for now, three other countries—Spain, the Czech Republic and Slovakia—after welcoming progress from them since it gave all nine of them a last chance in January.

The European Environment Bureau, an umbrella group of activists who dubbed the nine a "toxic bloc," welcomed the legal action, saying it comes as no surprise after "too many final warnings."

However, EEB's Margherita Tolotto said the process behind such action should be "far more transparent" to allow citizens to know why some countries are taken to court and others not.

"European air quality laws are being broken on a continental scale," Tolotto said.

'Arbitrary' limits

A large majority of member countries do not respect the EU rules, and yet, critics say, they are less strict than those of the WHO, for example, on particulate matter.

The EEA said between 16 percent and 20 percent of people living in European cities were exposed to dangerous levels of PM10 between 2013 and 2015—but the proportion increases to between 50 percent and 62 percent if WHO standards are applied.

Emissions laws have been a key target for environmental activists since the "Dieselgate" scandal erupted in 2015, when Volkswagen admitted to manipulating 11 million diesel vehicles worldwide to cheat regulatory emissions tests.

But Bas Eickhout, a European Parliament member from the Greens party, said that the laws themselves were "not the problem" but the fact that they are not properly enforced.

"Look at Dieselgate," Eickhout said.

The crackdown is also uneven across industrial sectors.

EU law is "very strict" on road transport, but regulations on other industries are different, said Jens Gieseke, an MEP from the centre-right European People's Party, the largest grouping in the EU Parliament.

The emissions limits become "arbitrary", Gieseke said.

Others lay the blame on EU governments, saying they vote for impressive-looking limits at Brussels summits, but then fail to crack down at home.

Nonetheless, Europe has achieved a few successes in improving its air quality.

Emissions of sulphur dioxide, the main cause of acid rain, have dropped by 72 percent since 2000, nitrogen oxide emissions have decreased by more than 40 percent, PM2.5 has fallen by more than 25 percent, according to Alberto Gonzalez Ortiz, an EEA expert.

But ammonia emissions have declined by only eight percent.

France is betting that its national air pollution reduction plan will mean that nitrous oxide limits will be exceeded at only three air monitoring stations in 2030, compared to 49 in 2010 and 10 in 2020.

Court decisions in February are leading the way for bans of an estimated 10 million old diesel vehicles in Stuttgart and Dusseldorf as well as other German cities.

The strongest shaking was recorded around 8:30 a.m., measured as a 4.4-magnitude earthquake. The floor of the summit crater has also dropped about three feet (90 centimeters), as the threat of a strong, explosive eruption at the top of the volcano loomed. The ground was deflating as the crater's lava levels fell, causing stress faults around the crater to move, resulting in the earthquakes. More were expected.

Ash spewed from the summit at Hawaii's Kilauea volcano, though emissions decreased from Tuesday.

There were occasional bursts of ash coming from the crater causing ash to fall downwind to several communities, though there were only trace amounts, said the Hawaiian Volcano Observatory. Ash plumes on Tuesday had spouted as high as 12,000 feet (3,657 meters) into the air, scientists said.

These plumes are separate from the lava eruptions happening roughly 25 miles (40 kilometers) away from summit, where about 20 lava fissures have destroyed more than two dozen homes and forced the evacuation of about 2,000 residents.

Dense, large rocks roughly two feet in diameter (60 centimeters) were found in a parking lot a few hundred yards away from Kilauea's summit crater, which reflect the "most energetic explosions yet observed and could reflect the onset of steam-driven explosive activity," the Hawaiian Volcano Observatory said in a statement, and continues to monitor activity.

Scientists say earthquakes may shake loose rocks underground and open up new tunnels for lava to flow.

Cracks formed on a highway near the entrance to Hawaii Volcanoes National Park, said the Hawaii Police Department. Much of the park remains closed.

"We're all safe, and I wish they'd open the park back up, but they have to keep it safe for everybody," said Ken McGilvray, an area resident. "We live on a volcano!"

Hawaii Gov. David Ige said the state is forming a joint task force that could handle mass evacuations of the Big Island's Puna district if lava from Kilauea volcano covers major roads and isolates the area. 

Hawaii Army National Guard Brig. Gen. Kenneth Hara, the task force commander, said he's anticipating potentially having to evacuate about 1,000 people, based on what he's been told by Hawaii County. But he said some people may choose to stay behind because they are self-sufficient.

Hara said there are currently about 1,200 soldiers and nine UH-60 helicopters currently training on the Big Island. He may also request forces from the U.S. Pacific Command if needed.

On Tuesday, the volcano discharged ash because of rocks falling into the summit, U.S. Geological Survey geophysicist Mike Poland said.

"There is very little wind at the summit," he said. "The plume, it's not near as ashy as it was yesterday, and it's rising more or less vertically over the summit region."

Because of the ash, USGS scientists operated from a backup command center at the University of Hawaii at Hilo.

Poland did not have an immediate height on the plume Wednesday since scientists were not staffing the observatory at the summit. They will have to rely on remote observations, he said.

"Things seem to be progressing largely as they have been, except for a shift in wind and less ash," Poland said.

Scientists remained on alert for more violent activity. Geologists have warned that the summit could have a separate explosive steam eruption that would hurl huge rocks and ash miles into the sky. But it's not certain when or if that might happen.

For those on the ground near the lava vents, health warnings were issued because of dangerous volcanic gases.

An air-quality alert was in effect for an area near the Lanipuna Gardens subdivision. That area was evacuated shortly after the eruption began May 3. Most fissures are in that subdivision or the adjoining Leilani Estates neighborhood.

Several fissures remained active Wednesday, producing lava spatter. Lava from one fissure that had been clearing a path toward the ocean, about 2 miles (3 kilometers) away, had not advanced in the last 24 hours.

In the absence of rules, travel agencies offer trips to the region on boats sometimes equipped with helicopters or submarines, according to Segolene Royal, French ambassador for the Arctic and Antarctic poles.

"This activity creates considerable disturbance ... we are witnessing a race toward large-scale tourism that is dangerous for ecosystems," she said at the assembly on Wednesday.

During the austral summer of 2016/2017, around 44,000 tourists set off for Antarctica, compared with just 9,000 in 1995/1996, according to French authorities.

However, the push for regulation is not about banning tourism, former environmental minister Royal said, but rather about ensuring it is managed in compliance with the treaty and its environmental protection protocol.

In Buenos Aires, the Antarctic Treaty Consultative Meeting —whose mission is to regulate human activity on the continent—also sought to encourage scientific cooperation between countries that have collectively set up around 100 research bases across the ice.

Also up for analysis is China's proposed fifth permanent scientific station in Antarctica, which would be located in the Ross Sea area south of New Zealand.

Makoko, to be blunt, is an environmental eyesore. It is a vast slum of wooden shacks built on stilts in the brackish, blackish, thickly-polluted lagoon in the heart of Lagos, Africa's biggest megapolis.

The sprawling community began in the 19th century as a fishing village for immigrants, who settled on the water's edge.

As more arrived and land became rare, people started to move out onto the water. Over time, Makoko became a floating realm of perhaps a quarter of a million people, although the real number is anyone's guess.

Here, a famously vibrant city has taken root, defying the lack of sanitation, the compacted rubbish and the reeking, greasy water, where impromptu churches and clinics have also found a home.

Today, though, Makoko and other lagoon shantytowns face a threat: urban regeneration in a city of some 20 million people that is starved of land.

In 2016, the governor of the state of Lagos, Akinwunmi Ambode, vowed to evacuate all waterfront shantytowns—a population totalling about 300,000, according to the Nigerian Slum/Informal Settlement Association.

A few months later, 30,000 people lost their homes when one of the slums, Otodo Gbame, a poor fishing community close to the upmarket southeastern district of Lekki, was razed.

Over three days, the district was set alight then bulldozed, reducing tens of thousands of homes to piles of smouldering wood and corrugated iron.

At least three people died when armed police moved in with bulldozers, setting fire to the area and chasing some residents into the nearby lagoon, locals said.

On Tuesday, about a hundred gathered to mark their eviction.

Former residents say they have yet to receive the relief or resettlement that the authorities promised.

Mostly from the ethnic Egun tribe, they trace their roots to Benin but say they have been living in Lagos for over a century.

But like the vast majority of the city's poor, they do not have title deeds to prove it.

"My father used to be a fisherman, I used to be a fisherman, but they destroyed my boat," said Isaac Azin, aged 36. "I live in Oreta now (another community), but people they don't want us there. They have their own issues."

'Don't want the poor'

In the shoreline neighbourhood of Ebute Metta, local people are incensed by what happened on December 28 last year.

Informal sawmills were destroyed, they say, by police and so-called "area boys"—gangs of toughs paid to clear out the area.

"Mr James," a man in his fifties laments the loss of his fine workshop and the generator that he used to provide power for it.

"The big men, they don't want poor people to exist in Nigeria", he said.

In communities who live around the lagoon, life is hard.

People tease out a living from fishing, from working on the shipments of wood floated downriver and from dredging—using buckets to haul sand from the sea bed off the Lagos coast, which is then sold to the construction industry.

But Lagos has a history of demolishing entire neighbourhoods.

In 1990, the authorities demolished Maroko, a shanty town in the well-heeled suburb of Victoria Island, forcing some 300,000 out of their homes.

On the site where it once stood, there now stands a popular South African shopping mall with international chains catering to the Lagos elite.

Lama Babu Sherpa reached the summit with a team of climbers and other guides on Monday, but became separated from the group as they descended and has not been seen since.

A government official at Everest base camp confirmed that Lama was presumed dead.

"Climbers found his clothes and other belongings but not the body," Gyanendra Shrestha, a government liaison officer, told AFP.

"He has been missing for such a long time now, it would be near-impossible for him to survive."

Mingma Sherpa of Seven Summit Treks, Lama's employers, said the team had been hit by strong winds as they reached the summit.

"The other sherpas were taking care of the members and they thought that he would come (down) but he didn't," he said.

Another team of climbers from the same mountaineering outfit reached the summit on Wednesday and looked for the missing guide on their descent.

"They searched in the summit area but they couldn't find his body," Mingma said, adding there was no way Lama could survive three nights exposed on the mountain.

Around 100 people have reached the summit of Everest this week as the busy spring climbing season—which runs from April to May—got into full swing.

Nearly 350 climbers have paid for permits to climb Everest from the Nepal side this season. Another 180 are attempting from the northern side in Tibet.

Most ascend with at least one guide, doubling the overall number of climbers heading for the top.

Foreigners must pay $11,000 for a permit but cut-price climbing outfits skimping on safety requirements have flourished in recent years, luring amateurs to the 8,848 metre (29,029 foot) peak.

The rapid growth in the climbing industry has accompanied complaints of overcrowding and fears that inexperienced mountaineers are putting themselves and their guides at risk.

Last year seven people lost their lives on Everest while nearly 570 made the summit, most ascending from Nepal.

Huge swathes of land in Chile, Brazil and Argentina are covered with millions of Araucaria, or monkey puzzle trees, thanks to people planting or cultivating them more than a thousand years ago, a new study shows. Recent logging means the landscape is now one of the world's most at-risk environments.

It had been thought the forests expanded due to wetter and warmer weather. But the research shows the rapidly expanding pre-Columbian population of South America, Southern Jê communities, were really responsible.

New excavations and soil analysis shows the forests, still hugely culturally and economically important to people living in South America, expanded between 1,410 and 900 years ago because of population growth and cultural changes.

Dr. Mark Robinson, from the University of Exeter, who led the British Academy and AHRC-FAPESP-funded research, said: "Our research shows these landscapes were man-made. Communities settled on grassland, and then—perhaps because they modified the soil, protected seedlings or even planted trees—established these forests in places where geographically they shouldn't have flourished."

The forests date back to the period when dinosaurs roamed. The iconic monkey puzzle tree, or Parana pine, has grown in the region for thousands of years. Its nuts were one of the most important food sources for ancient communities, attracted game for hunting when nuts were ripe. They were also a valuable source of timber, fuel and resin, and became an integral part of southern Jê cosmology. Communities still call themselves "people of the Araucaria", and hold festivals to celebrate the forests.

Of the 19 species of Araucaria tree, five are classified as endangered and two, including the Brazilian Araucaria angustifolia, are critically endangered. Reports from the late 1800s describe trees with diameters of over 2 m, reaching 42 m in height. Modern trees are only around 17.7 m tall.

The archaeological analysis began because the experts, from the University of Exeter, University of Reading, University of São Paulo, University of New Mexico, Universidade Federal de Pelotas and Universidade do Sul de Santa Catarina, noticed that in areas of low human activity forests are limited to south-facing slopes, whereas in areas of extensive archaeology, forests cover the entire landscape. They were able to analyse soil isotopes reflecting vegetation and archaeological evidence from Campo Belo do Sul, Santa Catarina State, Brazil, to test whether this pattern was directly related to past human activity.

The study shows the forests first expanded around 4,480 to 3,200 years ago, most likely near streams, and this may have been caused by a wetter climate. But a more rapid and extensive expansion across the whole region later happened between 1,410 and 900 years ago, when forests expanded into highland areas. The weather during this time was dry and less humid. This expansion of the forests coincides with population growth and increasingly complex and hierarchical societies in South America.

The expansion in forests reached a peak around 800 years ago. The number of people in South America declined 400 years ago when European settlers arrived in the area. The population did not begin to recover until the 19 century, when loggers began exploiting the Araucaria forests for timber.

Professor José Iriarte, from the University of Exeter, another member of the research team, said: "This study shows the Araucaria forests were expanded beyond their natural boundaries, they were used sustainably for hundreds of years, and conservation strategies must reflect this so they balance protection, heritage and economic development."

Uncoupling human and climate drivers of late Holocene vegetation change in southern Brazil is published in the journal Scientific Reports.

The report, posted this month on the website of the U.S.-based organization that conducted the study, said the Sambor dam would "generate large power benefits to Cambodia, but at the probable cost of the destruction of the Mekong fishery, and the certain enmity of Vietnam."

It said the dam designed by China Southern Power Grid Co. would have a 620 square kilometer (239 square mile) reservoir and dwarf the biggest dam currently being built on the Mekong, the Xayaburi dam in Laos, which was bitterly opposed by environmentalists for years.

The experts at the Natural Heritage Institute who authored the report, submitted to the Cambodian government late last year, recommended it defer the project while studying "better" alternatives such as using solar power to augment existing hydroelectric dams.

Alternative sites upstream where the Mekong separates into several channels are possible but either financially unfeasible or only marginally less destructive than the site currently envisaged for the 2,600 megawatt dam, the study said. Possible mitigation measures are either unproven or have a poor track record, it said.

The dam would block fish migration from the giant Tonle Sap lake in Cambodia which is crucial for reproduction and replenishing what scientists say is the world's most productive fresh-water fishery. It would also prevent riverbed sediment that fertilizes the Mekong Delta rice bowl from moving down river, a particular problem for Vietnam where delta farmlands are being destroyed by saltwater incursion from the sea.

"The dam and the reservoir would create a barrier that would be devastating for the migratory fish stocks," the study said.

It also warned that a population of about 80 critically endangered Irrawaddy river dolphins would likely be wiped out because the deep river pools they use as a dry season refuge would become filled with sediment blocked by the dam.

Cambodia's government, closely allied with China, its northern neighbor, and the recipient of substantial Chinese aid and investment, has not publicly commented on the report.

Seven dams that China built on the Mekong headwaters in its territory are already a headache for Southeast Asian countries, reducing the amount of sediment floating downstream by as much as half, according to researchers.

The Chinese dams were blamed for exacerbating a Southeast Asian drought in 2016, but countries in the region are pressing ahead with plans for Chinese companies to build a slew of other Mekong dams to meet growing demand for energy. Laos, one of the poorest countries in Asia, is pinning development hopes on becoming a source of power for its neighbors.

The new understanding will help researchers better predict the likely impact of climate change and rising CO2 levels on these critically important plants. Called 'C₄ plants' after their alternative photosynthetic pathway, these plants include a wide variety of native tropical, subtropical and arid grasses as well as saltbushes. C₄ crops include sugarcane and corn.

"C₄ plants evolved to be able to photosynthesise under warm, dry, and low CO2 conditions, with a special ability to take advantage of summer rainfall," says lead author Jake Andrae, Ph.D. candidate in the University's School of Physical Sciences and Sprigg Geobiology Centre. "As a result, they dominate the vegetation of Australian tropical, subtropical, and arid regions today.

"But despite being the most C₄ dominated continent today, little is known about the initial C₄ expansion in Australia."

The researchers analysed fossilised leaf waxes and pollen preserved in marine sediments. They measured the chemical signatures from these remnants, to reconstruct how and when C₄-dominated ecosystems first rose to prominence in Australia.

"In many regions around the globe, C₄ plants became prevalent between six and eight million years ago, which is thought by some to be the result of falling global atmospheric CO2 concentrations during this time," says project leader Dr. Francesca McInerney, Australian Research Council Future Fellow at the University of Adelaide.

"Surprisingly, in north-west Australia C₄ plants did not expand at this time in spite of regionally arid conditions and falling atmospheric CO2, both of which should have promoted C₄ vegetation. Instead, C₄ vegetation expanded across the landscape only 3.5 million years ago, several million years later."

The authors say that the rise of C₄ plants in Australia was likely the result of a strong summer monsoon that developed around that time.

"The difference in the timing of the expansion of C₄ plants in Australia from other parts of the globe demonstrates that regional climate changes are important in driving vegetation change," Dr. McInerney says.

"In the future, the interaction between global atmospheric CO2 and regional changes in seasonality of rainfall is likely to play an important role in the distribution of C₄-dominated ecosystems. Rising CO2 will place C₄ plants at a disadvantage, while rising temperatures, and changes in the season and amount of rainfall, could favour them.

"In Australia, C₄ plants are critical to grazing, soil carbon storage and biodiversity. We need to understand the factors that are likely to influence their survival in the future, to provide a basis for future conservation of these important plants."

The research, in collaboration with Columbia University and University of Melbourne, has been published online in Geophysical Research Letters.

More information:
J. W. Andrae et al. Initial Expansion of C4 Vegetation in Australia During the Late Pliocene, Geophysical Research Letters (2018). DOI: 10.1029/2018GL077833

Most living organisms have settled into ecological niches, and one of the decisive factors in their choice of habitat is a certain temperature . Marine animals such as tropical species need warmer water for their metabolism; animals that depend on a higher oxygen content require colder water. They therefore migrate either toward the poles or the equator as soon as the temperature changes, and have been doing so for millions of years. "Whilst the climate appears to be changing more rapidly today than ever before, the climate also changed rapidly in the past, forcing organisms to migrate in order to survive. Adaptation tended to be the exception," says Prof. Wolfgang Kießling, Chair of Palaeoenvironmental Research.

By investigating fossils, Prof. Kießling and Dr. Carl Reddin, who is also at GeoZentrum Nordbayern, have shown that coral, molluscs and sponges have been following their preferred cold and warm zones for a half-billion years. Isotherms (geographic lines denoting the same temperature, for example 20 degrees C) shift toward the poles or the equator as soon as the global temperature rises or decreases. Isotherms have been shifting toward the poles for several years due to global warming.

The tendency toward climate-related migration is most apparent in tropical species. This may be due to the fact that several of these species live near the thermal maximum for complex organisms of 35-45 degrees C . Current global warming trends are driving marine animals toward the poles, provided there is a suitable habitat they can migrate to.

How did the palaeobiologists discover this prehistoric migration pattern? First, they determined the geographic coordinates of the area in which the fossils were found when they were alive. Using a model, they determined how the tectonic plates have moved since the time when the animals were living and combined the results with the current coordinates of the location where the fossil samples were discovered. This enabled them to retrace changes in fossil species composition over long time periods. The researchers used a global database that they helped to set up that contains records of all fossils ever found.

The results are also significant for the present. Wolfgang Kießling and Carl Reddin expect that the current shifts will affect mostly tropical species, and it is thought that there will be a significant reduction of such species in the long run. Research up to now has largely been limited to central latitudes, where migration is already occurring on a large scale.

More information:
Carl J. Reddin et al, Marine invertebrate migrations trace climate change over 450 million years, Global Ecology and Biogeography (2018). DOI: 10.1111/geb.12732

Just ask the residents of Stanley, Victoria, whose four-year court battle to stop a farmer bottling local groundwater for Japanese beverage giant Asahi ended in failure last month. They were left with a A$90,000 bill for legal costs.

Locals have clashed with the bottled water industry in many parts of the world, including the United States and Canada, and perhaps most famously in the French spa town of Vittel, where residents have accused Nestlé of selling so much of their water to the rest of the world that they barely have enough left for themselves.

These conflicts demonstrate the challenge of balancing the competing demands on water drawn from underground. Compared with surface water, which is less tricky to monitor, groundwater is far harder to govern.

Under the Australian Constitution, water is primarily governed by the states. In Victoria, groundwater in high-use areas is managed using groundwater management plans under the Water Act, and water for commercial or irrigation purposes requires a take and use licence. This licence specifies the maximum volume of water a user is allowed to divert each year and under what conditions—what is often called an 'entitlement'.

If a licence-holder wants to amend their licence, they need to apply to their regional water corporation.

It was one such application that triggered the dispute in Stanley. Local farmer Tim Carey applied to change the source of 19 million litres of his existing licence from surface water to groundwater, and from agricultural to commercial purposes. This would allow him to truck the water to a bottling plant run by Mountain H2O, owned by Asahi.

The changes were approved by Goulburn-Murray Water under the local water management plan. Stanley's residents were concerned about the impact on irrigation and the environment, and tried to challenge Carey's operation under local planning laws. But the court said that his approved water licence meant he didn't need planning approval too. With no clear legal options now left for local residents, that may well prove to be the final say on the matter.

How did this happen?

Unfortunately, before about 1980, water entitlements were given away like kittens by various water agencies. As a result, in some areas, users are entitled to much more water than they actually use—sometimes more than is sustainable. And politics generally precludes any intervention to amend these inflated entitlements once the licence-holders have become used to having them.

Extensive droughts in the late 1970s and early 1980s, combined with the Darling River's striking algal bloom in the early 1990s, catapulted the importance of effective water management into the public consciousness.

In 1997, this resulted in "the cap" – limits on surface water diversions in the Murray-Darling Basin. However, the cap didn't limit groundwater extractions, which then increased dramatically. The regulation of groundwater, memorably described in an 1861 court case as too "secret, occult and concealed" to even attempt, has long lagged behind that of surface water.

It wasn't until the Millennium Drought (2000-09), with the advent of the National Water Initiative and the federal Water Act 2007 that Australian groundwater management underwent significant, large-scale reform. The main thrusts of the reforms were the development of legal and planning frameworks to achieve sustainable management of surface and groundwater, and the restructuring of water markets to be nationally compatible.

The new water governance regime created under the federal Water Act, under which the Commonwealth assumed important powers over waters in the Murray-Darling Basin, allows for groundwater markets and new limits on groundwater withdrawals. Groundwater trading is generally constrained by rules that require the "to" and "from" locations to be hydrologically connected to one another.

Stanley's groundwater falls within a new mega-planning area that covers great swathes of northern Victoria. The new management plan for this area is due at the end of the year, but is currently only 30% complete.

Even if the plan is finished on time, groundwater sustainability in regions like the Ovens might elude us. Limits on water extraction are generally based on the entitlements in the area. But as current groundwater usage is less than those entitlements, "sleeper" licences can still be activated. During shortages, when the economic value of water peaks, people can trade water that would otherwise remain unused. In some management regions, the total entitlement volume is roughly double or more than the actual usage.

The Stanley case shows how communities can mobilise when groundwater moves from one use to another. If new plans further encourage groundwater markets, we should brace ourselves for more of the same – although it is unclear whether other communities would enjoy any more legal success than the people of Stanley.

What are management decisions based on?

High-profile cases like Stanley's highlight the need for a robust scientific basis for licensing decisions. Communities facing change will have a difficult time accepting decisions that are not supported by rigorous science.

Unfortunately when it comes to groundwater, it's far from straightforward to work out how much water is down there and where it goes. An expert hydrogeologist retained by Stanley's residents argued that the modelling used to estimate the impact of the bottled water extractions was very simplistic. Mapping groundwater with an overly simplistic model is akin to using an identikit sketch of a smiley face to catch a criminal.

But water corporations have finite resources, and if we want in-depth analysis, then we need to invest in management planning tools such as drilling programs and numerical groundwater models supported by monitoring data and surveys of groundwater-dependent ecosystems. This sort of analysis is time-consuming, expensive and currently a political stretch. Governments only tend to spend serious money on groundwater investigations once people start running out of water.

However, if we want to get groundwater licensing right, it needs to be scientifically robust, environmentally sustainable, and procedurally fair.

As Stanley's residents discovered, there might be no second chance.