Climate Central News

A feed from Climate Central, an independent organization of leading scientists and journalists researching and reporting the facts about our changing climate and its impact on the public.


 

28 June 2017. The Larsen C Rift is Racing to Its Conclusion

A rift has torn the Larsen C ice shelf asunder and now the outside edge of the ice is moving at an unprecedented pace. When it breaks off, it will become one of the largest icebergs ever recorded.

The crack is just eight miles away from breaking off what will likely be the second-biggest iceberg observed. The massive hunk of ice has already started to wiggle like a loose tooth. That includes ice near where the crack began, which is moving at an unprecedented speed of 33 feet per day. In the world of glacial-paced ice, that’s the equivalent of an all-out sprint.


Ice on the back end of the Larsen C crack is moving faster than it ever has before in another sign that calving is imminent. The images show ice shelf movement on the ocean side of the rift in early June (left) compared to late June (right).
Credit: Project MIDAS

“In another sign that the iceberg calving is imminent, the soon-to-be-iceberg part of Larsen C ice shelf has tripled in speed to more than 10 meters per day between 24th and 27th June 2017,” the scientists wrote on their Project MIDAS site. “The iceberg remains attached to the ice shelf, but its outer end is moving at the highest speed ever recorded on this ice shelf.”

{related}

The speed-up is the latest sign that an iceberg is truly on the brink of forming. Project MIDAS researchers have been monitoring the state of the ice shelf since October 2015. During that time, they’ve observed periods of massive growth in the length of the crack across the ice shelf, widening to the point where you could lay the Empire State Building on its side to form a bridge across the chasm. More recently, a new branch sprouted, further warping the ice.

The latest change brings the break-off date that much closer to happening, though researchers cautioned it could still be weeks before the crack breaks through completely. When it does, though, it will drastically alter one of the largest ice shelves on the Antarctic Peninsula.

Scientists estimate that 10 percent of the ice shelf will break off, an area roughly as large as Delaware. That will change how the remaining ice shelf behaves, though it will take years of monitoring to see how those changes play out.

The Larsen C rift is driven by natural processes, but climate change could play a role in what comes next for the ice shelf, either from warm water undercutting what’s left of the ice shelf or warm air causing melt ponds on the surface. Both would weaken the remaining ice and make it more susceptible to melt and possibly collapse, though it will take years for researcher to tease those signals out.

“The area of ice about to be lost has a different stress regime to the central parts of the ice shelf,” Bethan Davies, an Antarctic ice researcher at Royal Holloway, University of London, said. “This change in stress regime may make calving easier and result in an increase in calving events. We will be watching this over the next few years.”

{like}

28 June 2017. Sunnier Skies Driving Greenland Surface Melt

In the past two decades, the Greenland ice sheet has become the biggest single contributor to rising sea levels, mostly from melt across its vast surface. That surface melt is, in turn, driven mostly by an uptick in clear, sunny summer skies, not just rising air temperatures, a new study finds.

A late summer sunset and clouds over the Black and Bloom field camp in Greenland in August 2016.
Click image to enlarge. Credit: Black and Bloom (@Glacier_Albedo)

What’s causing the decline in cloud cover isn’t yet clear, but the work shows that understanding what’s behind the trend and developing ways to better represent clouds in global climate models will be crucial to predicting how much Greenland will melt in the future.

The nearly two-mile-thick Greenland ice sheet covers an area about three times the size of Texas and holds enough ice to raise global sea levels by 23 feet if it were all to melt. While that is unlikely to happen anytime soon, even smaller-scale melt can raise sea levels to the point that large swaths of coastal land will be claimed by the oceans by the end of the century, including many major cities, such as Miami and Shanghai.

Global sea level has already risen by about a foot since 1900. Greenland’s contribution to that rise has jumped since the 1990s, accounting for about 30 percent of sea level rise since then.

While some of the water Greenland is flushing out to sea comes from warming ocean waters lapping away at the glaciers that drain the ice sheet, most is due to the melt across its surface during the summer.

{related}

Stefan Hofer, a PhD candidate at the University of Bristol in England, and his colleagues looked into what the main drivers of that surface melt were, in particular the effect of cloud cover on melt.

In satellite data spanning the past two decades, they saw a significant decrease in cloud cover over Greenland starting in the mid-90s, which would mean more sunlight was falling on the ice and driving melt.

Climate models the team used suggest that every 1 percent reduction in cloud cover leads to another 27 gigatons of melt (the U.S. uses about 1.3 gigatons of water per day, according to data from NASA and the U.S. Geological Survey).

That sensitivity to cloud cover was “pretty astounding,” William Colgan, a senior researcher with the Geological Survey of Denmark and Greenland who wasn’t involved in the study, said in an email.

The work, detailed Wednesday in Science Advances, shows that about two-thirds of Greenland’s surface melt in the past two decades has been driven by decreasing clouds cover and only one-third by warmer air temperatures.

“Our results clearly show that the reduction in summer cloud cover is an important driver in the recent melt increase on the Greenland ice sheet,” Hofer said in an email.

Large meltwater lakes forming over the Greenland ice sheet in August 2016.
Click image to enlarge. Credit: Black and Bloom (@Glacier_Albedo)

The results of the study jibe with the results of another study released Monday in Nature Climate Change that found that the acceleration of global sea level rise over the past decade was mostly due to Greenland melt.

Other factors can come into play in particular melt events, such as the major surface melt that occurred in mid-July 2012, when 97 percent of the ice sheet experienced some degree of melting. In that case, particularly high temperatures played a role, as did soot from wildfires that darkened the ice surface, making it absorb more sunlight, according to previous research.

The decrease in cloud cover noted in the new study is in turn linked to a shift in a natural climate cycle called the North Atlantic Oscillation, which has been in a strongly negative phase since the mid-90s (the most strongly negative phase in 160 years of data). That negative NAO phase, in turn, leads to less cloud cover over Greenland.

But what is ultimately causing that negative NAO isn’t yet clear. It could be a particularly wild natural fluctuation, or it could be linked to shifts in the major circulation patterns of atmosphere caused by the rapid warming of the Arctic. But that latter link is a contested area of research.

The study does make it clear, though, that to accurately predict just how much Greenland’s melt will contribute to future sea level rise, climate scientists need to get a better handle on what is driving these shifts and better representing them in climate models, which don’t capture the recent shift in cloud cover.

“This study shows how important cloud processes are to get right in models when calculating the amount of melt from the ice sheet and this is one of the big challenges in climate modeling in general,” Ruth Mottram, a climate scientist at the Danish Meteorological Institute, who also wasn’t involved in the study, said in an email.

{like}

28 June 2017. These NASA Images Show Siberia Burning Up

Siberian wildfire season is off and running with multiple blazes searing the boreal forest and tundra. It’s the latest example of the vast shifts happening to the forests that cover Siberia and the rest of the northern tier of the world as climate change alters the landscape.

Those forests are burning at a rate unheard of in at least 10,000 years due largely to rising temperatures. They contain vast reserves of carbon stored in trees and soil and when they burn, they send that carbon into the atmosphere. That creates a dangerous cycle of more severe wildfires and ever rising temperatures.

A satellite image captured on June 23, 2017 shows the extent of wildfires burning across Siberia.
Credit: NASA Earth Observatory

The current constellation of conflagrations had burned through roughly 133,000 acres to the west of Lake Baikal in southern Siberia as of last week. Strong winds have sent smoke spiraling hundreds of miles northeast, impacting air quality across the region.

{related}

NASA’s satellites captured the scene on Friday from a few different vantage points. The Aqua satellite captured the extent of the thick plumes of smoke and fires dotting the region while the Suomi NPP satellite was able to analyze the air quality. Both show the stunning breadth of impacts wildfires can have. The Suomi NPP measurements in particular show that the aerosol index — a measure of air quality — hit 19, a mark that denotes very dense smoke.

According to NASA Earth Observatory, scientists are also investigating signs that the fires were burning so intensely, they altered the local weather. There’s evidence pyrocumulus clouds formed, a phenomenon that occurs when wildfires burn so hot that they cause localized convection that eventually forms clouds.

The region where fires are burning has been a hot spot on the global temperature map. Since November, temperatures have been up to 7°F above average with some months far exceeding that mark. Climate change has been driving up temperatures around the world, but the northern tier of the planet has seen temperatures rise twice as fast.

Temperatures in Siberia were up 7.2°F above normal from November 2016-April 2017.
Credit: NASA

The extra heat has caused a string of severe wildfire seasons not just in Siberia, but in other stretches of the boreal forest that also covers Canada and Alaska. Last year, a massive blaze overran Fort McMurray, Alberta and became the costliest natural disaster in Canadian history. The year prior, Alaska had an explosive early start to its wildfire season. This is the third year in a row massive fires have lit up Siberia.

These individual events are part of a new reality that the boreal forest is burning at a rate unprecedented in modern history. Large fires in Alaska are twice as common as they were 75 years ago, according to Climate Central’s own research. That same report found that Alaskan wildfire season is 40 percent longer as well. Similar changes have been observed in Canada as well.

Climate change is expected to continue driving conditions that make destructive fires more common in boreal forests. That will reshape some of the most unique ecosystems on earth and the climate system itself. Boreal forests store about 30 percent of the world’s carbon. When they burn, they put that carbon in the atmosphere, increasing the impacts of climate change and creating a vicious cycle that will likely lead to more fires.

{like}

28 June 2017. States Betting on Giant Batteries to Cut Carbon

Some states and electric power companies are rolling out a new weapon against fossil fuels — giant batteries.

A growing number of states are requiring large batteries to be used to store electricity to help expand wind and solar power. The trend is catching on quickly as at least three states have created energy storage targets or incentives so far this year.

A Portland General Electric energy storage system.
Credit: PGE/flickr

Lawmakers in New York passed a bill last week requiring the state to create an energy storage target. Nevada passed a bill incentivizing energy storage in May, and Maryland passed an energy storage tax credit in April. Those measures follow California, Oregon, and Massachusetts, which have mandates for electricity storage in batteries.

Electric power plants have historically been America’s largest source of carbon pollution contributing to climate change. Today, electric power plants that run on both coal and natural gas emit large volumes of carbon dioxide — the primary cause of global warming.

But as more wind farms and solar power plants are built to help reduce climate pollution, electric power companies encounter one of the fundamental challenges with renewables: The flow of electricity from wind and solar farms isn’t steady — it fluctuates as the wind blows and the sun sets. Sometimes excess energy they produce goes to waste.

“We only produce solar electricity when the sun shines. We consume energy 24/7. We need to have means of supplying the electricity to consumers 24 hours a day. That’s one of the basic roles of energy storage,” said Janet Joseph, vice president of innovation and strategy for the New York State Energy Research and Development Authority.

Batteries help solve that problem.

If batteries are used to capture renewable power as it is generated, electric companies can use that stored electricity when it is needed the most, usually during the day when air conditioners are blasting and businesses have all their lights on. Today, electric power used for those high demand times comes from power plants running on natural gas.

{related}

The batteries that electric power companies use are huge. The Tesla PowerPack, for example, is composed of 16 pods that together weigh more than 3 tons and are 7 feet tall. The pods are daisy-chained together and provide hundreds of kilowatts of power.

New York officials say batteries are critical to the state’s goal of generating half of its electricity from renewables by 2030. As more states create energy storage incentives and targets, more power plants using fossil fuels are likely to be eventually replaced or supplemented with batteries, helping to cut the amount of time the power plants are used.

Jeremy Firestone, director of the Center for Carbon-free Power Integration at the University of Delaware, said mandates and incentives for energy storage in some of the most populous states will help reduce climate pollution and drive innovation. They will also help to lower energy storage costs as batteries are adopted more widely, just as costs for wind and solar installations have fallen as more have been built, he said.

“While climate is a ‘state’ goal, by leading the way and reducing the cost of storage, these states will facilitate the implementation of storage in other states and countries, leading to further climate benefits,” Firestone said.

Big companies are getting in the utility-scale solar game, including electric automaker Tesla. The company is producing large batteries that allow individual homes to store solar energy they’ve produced. Tesla is also building major utility-scale battery storage projects for electric companies in Hawaii, Connecticut and California.

Tesla partnered with Southern California Edison, a Los Angeles-area electric power company, to complete an energy storage facility in January large enough to supply electricity to 15,000 homes for four hours during times of highest electric power demand.

 An Avista energy storage battery in Washington State.
Credit: Jay Inslee/flickr

The project was built in response to the massive 2015 Aliso Canyon natural gas storage facility leak, which jeopardized the supply of natural gas to electric power plants. The state required utilities to find other ways of generating power during gas supply disruptions.

“The idea was to have non-natural gas (electricity) generation in Southern California,” giving the company greater flexibility to generate electricity and prevent power disruption, said Vibhu Kaushik, manager for generation strategy at Southern California Edison.

The company also uses batteries to supplement energy from some natural gas power plants at times of peak electricity demand. The batteries have allowed the plants to reduce the time they operate by about half, cutting their greenhouse gas emissions by 60 percent, Kaushik said.

In Arizona, which has no energy storage mandate, Arizona Public Service is conducting a test of energy storage used in both homes and at electric substations that will help the utility cope with the irregular flow of electricity from rooftop and utility-scale solar plants.

Arizona Public Service spokeswoman Annie Degraw said batteries help supplement the flow of power from a rooftop solar panel when a cloud blocks the sun, resulting in the panel producing less electricity for a few minutes.

The company is paying homeowners participating in the program a $30 monthly credit for 20 years to help test batteries connected to the power grid, Degraw said.

Many in the industry see a future when renewables and battery storage provide most of the electricity on America’s electric power grid. John Zahurancik, president of Virginia-based AES Energy Storage, which has built energy storage projects in several states, said that the company envisions a time in the near future when energy storage could account for at least 10 or 20 percent of America’s electric generating capacity.

Costs for the lithium-ion batteries used in energy storage projects have fallen by half in the past five years, already making them competitive with the cost of natural gas power plants today, he said.

“We have systems available today that are proving to be cost effective,” Zahurancik said. “We’re already starting to see batteries replace fossil fuel power plants.”

{like}

25 June 2017. Warming Brews Big Trouble in Coffee Birthplace Ethiopia

By Damian Carrington, The Guardian

Global warming is likely to wipe out half of the coffee growing area in Ethiopia, the birthplace of the bean, according to a groundbreaking new study. Rising temperatures have already damaged some special areas of origin, with these losses being likened to France losing one of its great wine regions.

Ethiopia’s highlands also host a unique treasure trove of wild coffee varieties, meaning new flavour profiles and growing traits could be lost before having been discovered. However, the new research also reveals that if a massive programme of moving plantations up hillsides to cooler altitudes were feasible, coffee production could actually increase.

Coffee cherries, hand-picked in Africa.
Credit: rogiro/flickr

Coffee vies with tea as the world’s favorite beverage and employs 100 million people worldwide in farming the beans alone. But climate change is coffee’s greatest long-term threat, killing plantations or reducing bean quality and allowing the deadly coffee leaf rust fungus to thrive. Without major action both in the coffee industry and in slashing greenhouse gas emissions, coffee is predicted to become more expensive and worse-tasting.

The research combined climate-change computer modelling with detailed measurements of current ground conditions, gathered in fieldwork that covered a total distance of 30,000km within Ethiopia. It found that 40-60 percent of today’s coffee growing areas in Ethiopia would be unsuitable by the end of the century under a range of likely warming scenarios.

But the study, published in the journal Nature Plants, also shows that major relocation programmes could preserve or even expand the country’s coffee-growing areas. “There is a pathway to resilience, even under climate change,” said Aaron Davis, at the Royal Botanic Gardens Kew in the UK, who conducted the work with Ethiopian scientists. “But it is a hugely daunting task. Millions of farmers would have to change.”

However, by 2040, such moves uphill will have reached the top of Ethiopia’s mountains. “It literally reaches the ceiling, because you don’t have any higher place to go,” Davis said.

The impacts of global warming are already being seen as temperatures have been rising steadily in Ethiopia for decades. Farmers report a longer, more extreme dry season and more intense rain in the wet season, with good harvests much less frequent than in their parents and grandparents’ time.

Coffee trees in Africa.
Credit: carsten ten brink/flickr

One famous coffee location likely to be lost is Harar. “In one area, there are hundreds if not thousands of hectares of dead trees,” said Davis. “It is a world renowned name and has been grown in that area for many centuries. But under all [climate change] scenarios, it’s going to get worse.

“Some of the origins, what you would call terroir in the wine industry, will disappear, unless serious intervention is undertaken,” he said. “It would be like losing the Burgundy wine region. Those areas are found nowhere else but Ethiopia, and because of the genetic diversity, the diversity of flavor profiles is globally unique.”

Both arabica and robusta coffee originated in Ethiopia and wild arabica plants are virtually unknown outside the country. The wild arabica varieties may well harbor traits for disease and drought resistance that could prove vital for the future health of coffee crops.

Prof Sebsebe Demissew, from the University of Addis Ababa and one of the research team, said: “Coffee originates from the highland forests of Ethiopia, and it is our gift to the world. As Ethiopia is the main natural storehouse of arabica genetic diversity, what happens in Ethiopia could have long-term impacts for coffee farming globally.”

The new research is a “brilliant piece of work”, according to Tim Schilling, chief executive of the World Coffee Research programme: “This is the only comprehensive, country-specific study I have seen that uses some of the best methods in climate modelling coupled to very rigorous ground-truthing — extremely useful for governments and industry and a model to be repeated.”

Just-picked coffee beans at farm in Cauca, southwestern Colombia.
Credit: CIAT/flickr

Schilling led an expedition into South Sudan in 2013 to confirm wild arabica coffee was also present in the Boma forest: “What we found was major degradation caused by climate change on the forest and the wild coffee under its canopy. That is pretty much what I think we can expect if nothing is done to preserve the arabica genetic treasure chest in Ethiopia.”

Schilling said new varieties and growing methods must be developed and that plantation “migration will have to be part of a plan B”. He added: “Plan C might be moving up in latitude and growing coffee in Southern France and Texas!” But he said funding all this is difficult when coffee producers are not making much money at present.

The Intergovernmental Panel on Climate Change concluded in 2014: “The overall predictions are for a reduction in area suitable for coffee production by 2050 in all countries studied. In many cases, the area suitable for production would decrease considerably with increases of temperature of only 2-2.5°C.” It said that in Brazil, the world’s biggest coffee producer, a temperature rise of 3°C would slash the area suitable for coffee by two-thirds in the principal growing states. In 2016, other researchers predicted climate change will halve the world’s coffee-growing area.

“People should also be thinking about the millions of smallholder farmers who put their coffee on the table,” said Davis. “The coffee farmers of Ethiopia are really on the frontline [of climate change] — they are the people who will pay the price first. In the longer term, the only truly sustainable solution is to combat the root causes of climate change.”

Reprinted with permission from The Guardian.

24 June 2017. Nuclear Decommissioning Threatens Climate Targets

By Geert De Clercq, Reuters

Decommissioning nuclear plants in Europe and North America from 2020 threatens global plans to cut carbon emissions unless governments build new nuclear plants or expand the use of renewables, a top International Energy Agency official said.

Nuclear and wind in Drôme, France.
Credit: Jeanne Menjoulet/flickr

Nuclear is now the largest low-carbon power source in Europe and the United States, about three times bigger than wind and solar combined, according to IEA data. But most reactors were built in the 1970s and early 80s, and will reach the end of their life around 2020.

With the average nuclear plant running for 8,000 hours a year versus 1,500-2,000 hours for a solar plant, governments must expand renewable investments to replace old nuclear plants if they are to meet decarbonization targets, IEA Chief Economist Laszlo Varro told Reuters.

"The ageing of the nuclear fleet is a considerable challenge for energy security and decarbonization objectives," he said on the sidelines of the Eurelectric utilities conference in Portugal. 

Renewables have grown rapidly in the past decade but about 20 percent of new low-carbon capacity has been lost from the decommissioning of nuclear plants in the same period, he said.

"This is just a taste of thing to come," Varro said.

Russia and India were building new plants, while China was bringing a new plant online every quarter, Varro said.

Kalinin Nuclear Power Plant in Moscow, Russia.
Credit: IAEA Imagebank/flickr

However, he said future projects in Japan were uncertain after the 2011 Fukushima disaster, while there was less appetite for new nuclear projects in Europe and the United States.

Financing new nuclear plants has become more challenging, partly because several new builds were running over budget, while in the United States nuclear has been struggling to compete against plants run on cheap shale gas.

Governments who chose the renewables route would have to consider upgrading power grids and invest in power storage to offset the variable nature of renewable generation, while those choosing nuclear would need to offer financial support as Britain has done for its plans, Varro said.

Wind and solar generation was expanding rapidly, but the pace needed to increase to meet climate stabilization goals. "At the moment it is not quickly enough," he said.

The biggest challenge was in Europe and the United States, where nuclear energy capacity was steady or falling, he said.

"If we do not keep nuclear in the energy mix and do not accelerate wind and solar deployment, the loss of nuclear capacity will knock us back by 15 to 20 years. We do not have that much time to lose," he said.

Reporting by Geert De Clercq; Editing by Edmund Blair

23 June 2017. We Couldn’t Monitor Larsen C Without These Satellites

The Larsen C ice shelf is about to calve one of the biggest icebergs on record.

The iceberg-to-be is hanging on by a thread, with just eight miles of solid ice standing in the way of a rift that’s spent years carving through the ice. Scientists can track the growth of the crack with precision during the summer season by flying over it, but even during the dead of Antarctic night, they’re still able to see it clearly thanks to eyes in the sky.

The evolution of the crack across the Larsen C ice shelf (seen in the lower right-hand corner) as it spreads 38 miles from January 2016-January 2017.
Credit: European Space Agency

Two European satellites, known as Sentinel-1, criss-cross over the region every six days like clockwork. Their sensors are able to see through clouds and darkness to provide a real-time image of the most-watched patch of ice on the planet.

“The close monitoring of this rift really is a success story for Sentinel-1,” Adrian Luckman, a glaciologist at Swansea University, said.

{related}

Luckman is part of Project MIDAS, a team of researchers intently monitoring the crack. He said without the satellite, researchers would only have access to low-resolution images or have to pay for data from private companies.

To monitor Larsen C, scientists are using what’s known as synthetic aperture radar. It’s particularly useful in polar regions because it can see through clouds and darkness, both of which are plentiful at certain times of the year at high latitudes. The same technology has also been used on space probes to image the surface of cloud-covered Venus.

With Larsen C likely to calve one of the largest icebergs on record, having instruments that can track it no matter the condition is crucial to improving researchers’ understanding of the polar regions. While the rift on Larsen C is likely due to natural causes, the instability that climate change is fueling in the Antarctic make these types of observations essential to know what comes next.

A composite Sentinel-1 image of northern Canada showing changes in sea ice extent in winter 2016-17.
Credit: European Space Agency

Because it’s polar orbiting, the Sentinel-1 mission also provides information on what’s happening on the other end of the planet. Climate change is taking a toll on the Arctic that’s in some ways even more dramatic. Sea ice is disappearing at an alarming clip and Greenland’s massive ice sheet and other land ice is also melting.

Monitoring changes now can help improve future predictions, but the satellites also provide important observations that can be used now in an otherwise data-sparse region.

“Their high resolution measurements are of significant value for numerous stakeholders beyond just scientists, e.g., shipping industry during the Arctic summer (and) navigation through sea ice,” Zack Labe, a PhD student studying the Arctic at the University of California, Irvine, said in an email. “I think this is a key point that we often forget. These remote sensing observations (like from the Sentinels) provide services to many industries on both land and water.”

Labe pointed to monitoring oil spills and creating forecasts for the Arctic as just two of the uses for the Sentinel-1 satellite data.

The two satellites are managed by the European Space Agency as part of its Copernicus program, which is designed to create a comprehensive monitoring program for changes around the world. There are three other missions currently in orbit and three more will be launched in the coming years.

Together, they’ll be used to monitor a wide array of planetary vital signs at a time when the world is rapidly changing due to carbon pollution.

{like}

22 June 2017. Climate Change Altering Droughts, Impacts Across U.S.

As a major drought devastated the West and Midwest beginning in 2012, farmers racked up billions of dollars in crop losses and water managers grappled with possible water shortages for millions of people as reservoirs dried up in the heat.

That drought is now gone. But scientists have found that the dry spell showed unusual wild extremes of wetness and warmth — indicators that climate change may be altering the typical characteristics of drought across the U.S., according to a new National Oceanic and Atmospheric Administration study published in the Bulletin of the American Meteorological Society.

Water levels in Lake Success, Calif., dropped to 4 percent of capacity during the state's devastating drought in 2014.
Credit: David Siebold/flickr

The stakes are high. Extreme drought across the U.S. has contributed to tens of thousands of job losses, unpredictable and often extreme rainfall and devastating wildfires that have left behind many millions of charred acres of land and billions of dollars in property losses.

Study author Richard Heim, Jr., a researcher at the National Centers for Environmental Information at NOAA, compared a nationwide series of dry spells beginning in 1998 to two other devastating droughts in the 1930s and 1950s, including the Dust Bowl.

{related}

He said one of the most unique features of the drought as it spread across the country in 2012 was that some parts of the country were outright soggy while others dried up in the sun. Compared to two earlier dry spells, a recent series of droughts beginning in 1998 saw the largest area of the U.S. with normal or above-normal precipitation.

“The main thing is the 1998-2014 drought episode is the warmest of the three major drought episodes. It’s also the wettest,” Heim said. “A huge chunk of the country is in drought (during that period) and other chunks are really wet.”

Warmer temperatures over the past 30 years and more frequent regional dry spells since 1998 are changing the water cycle, posing challenges for urban and agricultural areas throughout the country.

“When broken down by region, the 1998-2014 episode had more days with precipitation than the other two episodes for all regions except the southern plains and Lower Mississippi Valley,” the study says.

During that time, the Northeast and Midwest, which saw their own dry spells, received the most rain and snowfall, while much of the West dried out, the study says.

2012 was a critical year for drought in the U.S. Several ongoing regional droughts “merged” to create a massive nationwide drought leaving more than 60 percent of the country suffering severe levels of drought or worse.

Today, about 7 percent of the continental U.S. is in drought considered severe or worse, down from 22 percent in early January and 31 percent last November.

Research shows that when dry spells occur, climate change is likely to make them drier than they would otherwise be because warmer temperatures increase evaporation. It also means that when storms hit, more precipitation is likely to fall as rain than snow, shrinking the snowpack that’s important to storing water for cities and farmers to use during the dry season.

A Climate Central analysis shows that since 1949, 68 percent of weather stations between 2,000 feet and 5,000 feet in elevation in 42 states have seen a lower percentage of winter precipitation falling as snow.

The U.S. Drought Monitor in July 2012 at the height of the nationwide rought.
Credit: U.S. Drought Monitor

Benjamin Cook, an associate research scientist at Columbia University’s Lamont-Doherty Earth Observatory, who is unaffiliated with the study, said that though scientists can’t say definitively that global warming caused the most recent drought, climate change projections clearly show that drought intensity and risk will increase for much of the U.S. Warmer temperatures are already exacerbating recent droughts in California, the Pacific Northwest and the Colorado River Basin, he said.

Cook’s 2015 research shows that rising temperatures and decreasing rainfall driven by climate change are creating an unprecedented risk of severe drought in the Southwest and Central Great Plains, setting up drought conditions that could be worse than at any time in the last millennium, even worse than the Dust Bowl.

Heim’s study shows that one of the unusual characteristics of the most recent drought compared to those in the 20th century is that, on a national scale, the drought’s driest seasons were in the winter and spring. Warm temperatures during those seasons resulted in greater evaporation and transpiration, worsening drought conditions. The driest seasons in the previous droughts were fall and summer.

Cook said that the 2012 “merger” of regional droughts is unusual because different regions of the country typically see their wet and dry seasons at different times of year. California, for example, receives nearly all its precipitation during the winter, while the Central Plains see their wettest months during spring and early summer.

“For multiple regions to be in a period of extended drought simultaneously therefore requires a level of synchronicity across the climate system that is rare,” Cook said.

Heim said drought over the past 20 years was caused by different atmospheric conditions depending on the year.

For example, a more northerly shift in the track of the jet stream and storms since the 1970s have led to shifts in drought location and intensity in the U.S.

La Niña was among the triggers of the devastating California drought, along with a prolonged high pressure ridge over the Pacific Ocean that deflected storms northward, missing much of California during the height of its drought.

Jay Lund, director of the Center for Watershed Sciences at the University of California-Davis, said Heim’s study is “thought provoking,” but he said every drought is unique.

“Most droughts are a bit quirky in their character, and all droughts impact a different society and economy than their predecessors making each drought and its lessons substantially unique,” Lund said. “Still, it is very likely that higher temperatures will worsen the severity of droughts.”

{like}

22 June 2017. Atlantic Oil Surveys Could Kill Food Used By Fisheries

The microscopic animals that provide food for fisheries face previously unknown threats along America’s southern and eastern seaboards, and in oceans elsewhere, with new research warning of the potential for heavy impacts from oil surveys that blast noise into the sea.

Scientists in the Australian island state of Tasmania have added krill larvae and other plankton to the growing list of animals known to be affected by airguns trawled behind ships in search of oil reserves, earthquake faults and other buried features.

The Atlantic Ocean off Delaware.
Credit: Katie Wheeler/flickr

The Trump administration is moving to allow these seismic surveys from Delaware to Florida ahead of anticipated oil drilling, which had been blocked by the Obama administration. Such surveys are underway in the Gulf Coast and could precede any new drilling along coastlines in the U.S. and abroad.

There has so far been a “striking” lack of research into how airguns affect plankton, said University of Tasmania scientist Jayson Semmens. “Most of the work is done on whales.”

{related}

Semmens was part of a team that wanted to know how plankton are being affected, so they fired a 140-pound, 23-inch airgun into Storm Bay near Australia’s southernmost point. Airguns compress air then explosively release it, with reflections from the loud pulse monitored for clues as to what lies beneath the ocean floor.

Dead and living plankton sampled during air gun experiments in Tasmania.
Credit: McCauley et al., 2017, Widely used marine seismic survey air gun operations negatively impact zooplankton, Nature Ecology & Evolution.

With the aid of sonar, the scientists detected what they called a “hole” blown through patches of plankton. Sampling after airgun firings during mile-long sweeps with nets retrieved two-thirds fewer plankton, with many of the microscopic animals found dead — including all krill larvae.

The proposed Atlantic surveys would see arrays of airguns trawled by surveying companies up to 350 miles from the coast, fired every 10 seconds or so around the clock for up to a year. The new research suggests the proposal threatens to reduce the amount of food in the sea, as well as directly harm dolphins and other creatures.

Seismic surveys using large arrays of more powerful airguns than those used by the scientists are undertaken off the heavily drilled Gulf Coast, from Texas to Florida. As the Trump administration moves to open West Coast and Alaskan waters for new oil drilling, including inside marine sanctuaries, surveys would also be expected there.

Commercial surveys are also being undertaken the world over, harming wildlife at a time when climate change caused by the burning of oil and other fossil fuels is hurting fisheries.

As the Trump administration abandons environmental regulations and climate diplomacy, its efforts to boost fossil fuel production in the Atlantic and elsewhere could further accelerate warming. The proposed seismic tests will harm ocean ecosystems already stressed by warming.

Coral reefs that shelter growing fish are bleaching and dying in the heat. Fish sought by fishermen are moving in pursuit of cooler waters. Carbon pollution is acidifying waters, affecting shellfish and other species. And warming is reducing the amount of oxygen in the sea.

Deborah Steinberg, an ecology professor at the Virginia Institute of Marine Science who wasn’t involved with the study, published Thursday in the journal Nature Ecology & Evolution, said it was the first of its kind. That means it’s hard to know whether airguns used in the U.S. would have the same effects as were seen in Tasmania. It’s also hard to know why the plankton died in such large numbers.

“It’s reasonable to assume the results have implications for other regions,” Steinberg said. “The major group of crustacean zooplankton found in their study, copepods, are abundant across the world's oceans.”

Rules are often put in place requiring temporary work shutdowns when whales and other protected animals are detected close to survey vessels, or when they’re expected to be migrating through the area.

Such protections do little to protect plankton, however, which can be omnipresent. With fewer of these tiny animals in the sea, larger fish, sea lions, seabirds and other wildlife could go hungry more often, reducing populations and fisheries hauls.

North Atlantic right whales feed on plankton.
Credit: Florida Fish and Wildlife Conservation Commission/flickr

In reports and permit applications chronicling likely impacts of seismic surveys, it’s assumed that plankton are unaffected by airguns unless at close range, typically up to 30 feet away.

“There’s an assumption, which is incorrect,” Semmens said. His Tasmanian experiments detected a heavy impact on krill and other creatures up to 4,000 feet away — which was as far as the scientists looked. “It can’t be ignored.”

The study may provide environmental groups with additional legal ammunition as they prepare to oppose any new seismic testing permits. If airgun impacts on plankton are considered when permit conditions are set, that could affect how, where and when contractors for oil companies are allowed to use the technology to search for new reserves.

The surveying industry pointed to the preliminary nature of Thursday’s findings, which were the result of a limited number of samples from a single location. International Association of Geophysical Contractors President Nikki Martin said in a statement that it “falls short of what would be needed to provide a convincing case for adverse effects.”

North Atlantic right whales, which eat plankton, are at risk of extinction, and environmental laws that protect them and other species also protect their food supplies — including krill.

If the federal government doesn’t analyze the likely effects of acoustic testing on plankton prior to granting Atlantic permits, given the findings from Tasmania, “that will create legal vulnerability on their part,” said Kristen Monsell, an attorney at the Center For Biological Diversity.

The conservation nonprofit has filed 23 lawsuits against the Trump administration already. It helped force the Obama administration to begin an environmental review of the environmental impacts of Gulf oil surveys, which may eventually lead to new restrictions to protect wildlife there.

{like}

20 June 2017. It’s So Hot in Phoenix, Planes Can’t Take Off

An intense heat wave is crippling the West this week, sending the mercury above 120°F in places like Phoenix. In a sign of just how hot things are getting, some airlines have had to cancel flights because of the heat.

American Airlines said it cancelled 50 flights out of Phoenix Sky Harbor aboard Bombardier CRJ aircraft on Tuesday because the planes can’t operate above 118°F.

Heat waves are intimately tied to climate change as rising background temperatures make them more intense and common. The latest batch of heat will cook an area from northern California to western Texas, a region home to some seven of the 10 fastest-warming cities in the country.

Temperature records have already fallen across California and heat will build throughout the week. Sacramento, San Jose, Palm Springs, Fresno and Death Valley all set daily highs on Monday. But the hottest temperatures aren’t even expected to arrive until Tuesday. They’ll last through Thursday, and forecast highs mean the region could set all-time records.

{related}

Phoenix, Tucson and Las Vegas are forecast to be within striking distance of all-time records. All eyes will be on Phoenix, which is ground zero for the heat wave. Temperatures are forecast to climb to 120°F on Tuesday, just 2°F shy of its all-time record. When it comes to extreme heat, Arizona is one of the many states at risk.

All-time record hot or not, the extreme weather has the potential to be life-threatening. The National Weather Service has issued an excessive heat warning and its Phoenix office has said “heat of this magnitude is rare, dangerous and very possibly deadly.”

Perhaps it’s no surprise these cities could be in line to set records. Phoenix is the second-fastest warming city in the U.S. over the past 50 years while Las Vegas comes in at third and Tucson at seventh. Climate change is largely responsible for boosting those background temperatures, increasing the odds of setting record highs like the ones currently broiling the region. The heat island effect only compounds the risks of deadly heat in cities.

“Across the world we're finding that we can link unusually warm weather events to climate change,” Andrew King, a climate researcher at Australia’s ARC Centre for Excellence, told Climate Central in March following February’s intensely mild weather. He added climate change is almost certainly playing a role in almost all extreme heat events “for most of the world.”

While the heat wave this week in the West has not been specifically attributed to climate change, it’s probably safe to say background warming is playing a role and the impacts we’re seeing will only become more pronounced in the future.

Take the grounded flights, for example. They’re what one group of scientists have dubbed a “hidden cost of climate change.” That’s because higher temperatures generally translate to thinner air, making it harder for airplanes to take off. The solution is either to ground flights or bump people and packages to make planes lighter.

If carbon pollution keeps going at its current rate, Phoenix could see 20 more days a year by 2100 where flights are restricted to a maximum takeoff weight of 10,000 pounds. That’s currently a rare occurrence. Other airports like LaGuardia in New York and Reagan National in Washington, D.C. could see even more days with weight restrictions.

But canceled flights are a climate change inconvenience. There are far more serious impacts that will put more lives at risk if carbon pollution continues unchecked. Research published on Monday showed that half the world’s population will face life-threatening heat waves by 2100 unless carbon pollution is curbed.

The summer average temperatures in Phoenix could be more like Kuwait City by the end of the century, making this currently rare heat routine.

{like}

20 June 2017. Desert Basins Could Hold ‘Missing’ Carbon Sinks

Deserts across the globe may contain some of the world’s “missing” carbon sinks — land masses scientists had not previously identified that absorb carbon from the atmosphere, according to researchers at China’s Lanzhou University.

A study published Monday in the journal Nature Geoscience found that closed, or endorheic, basins in deserts — areas into which water flows but doesn’t flow out — are significant storehouses of carbon, but their ability to act as carbon sinks may diminish as the globe warms.

An arid endorheic basin in South Australia.
Credit: BRJ Inc./flickr

Understanding carbon sinks and how they function is critical for scientists to calculate the world’s carbon budget  — the estimate showing how much countries can pollute before global warming exceeds the level that climate scientists consider dangerous — 2°C (3.6°F).

Study lead author Li Yu, a paleoclimatologist at Lanzhou University, said there is a lot of uncertainty about how carbon sinks work, and scientists can only create an accurate carbon budget if they study each kind more thoroughly.

{related}

Though scientists know how much carbon dioxide humans emit each year, they don’t know exactly what happens to the carbon that is absorbed by the land. About 40 percent of human carbon emissions stay in the atmosphere, about 30 percent is absorbed by the world’s oceans, and the rest is absorbed by carbon sinks on land, according to the National Center for Atmospheric Research.

Arid regions, which cover about 47 percent of the earth’s land mass, are thought to make up the world’s third-largest carbon sink on land.

The world has a lot of endorheic basins in arid regions, including the Okavango Basin in southern Africa and the fast-disappearing Aral Sea in Kazakhstan. In the U.S., the Great Basin Desert in Utah, Nevada and Oregon is an endorheic basin. Streams and rivers flow into the basins, but instead of flowing out, they disappear underground or simply evaporate.

As the world continues to warm, climate change may affect the water cycle, reducing the ability of desert basins to act as carbon sinks. Carbon that would be naturally stored in the soil may return to the atmosphere as soil moisture evaporates in higher temperatures.

The ability of deserts and other ecosystems to sequester human carbon emissions is critical to climate policies such as the Paris climate agreement because it’s a major factor in calculating how quickly atmospheric carbon will accumulate in the atmosphere. As less carbon is absorbed by the land and oceans, more remains in the atmosphere.  

Atmospheric carbon concentrations must not exceed 450 parts per million (ppm) if global warming is to be prevented from exceeding 2°C (3.6°F), the primary goal of the Paris agreement. However, earth is running out of time to limit more warming. The atmosphere blew past the 400 ppm mark last September and it’s on a trajectory to pass 450 ppm within about two decades.

Using estimates of how much carbon endorheic basins in China absorbed during a warm period 6,000 years ago, Yu’s team estimated how much carbon endorheic basins store each year. Today, at a time when the earth may be much hotter, the basins store much less carbon, suggesting that climate change may be affecting the ability of arid regions to act as carbon sinks, Yu said.  

Sevier Lake, in Utah's Great Basin, is an endorheic basin.
Credit: Doc Searls/flickr

Yu estimated that closed basins pack away about 152 million metric tons of carbon each year worldwide today, compared to 211 million metric tons 6,000 year ago.

That means the world’s endorheic basins today store carbon equivalent to the amount of carbon released into the atmosphere by seven hurricanes similar in magnitude to Hurricane Katrina, said Steven McNulty, a U.S. Forest Service landscape ecologist studying the carbon cycle and an ecology professor at North Carolina State University who is unaffiliated with the research.

McNulty said Yu’s study shows that desert basins can lose their stored carbon, but the researchers need more detail about about why that has happened.

Desert basins can lose the carbon they’ve stored as the climate changes because rising temperatures can cause soil to release the carbon it holds back into the atmosphere, Yu said.

Both global warming and water use for farming and industrial development can change the water cycle and reduce the carbon deposited in the soil, he said.

The amount of carbon in the soil and the ability for soil to act as a carbon sink is expected to diminish as temperatures rise. The mechanisms for that may be different from place to place, but the effect could be significant.

Research published last year and led by the Netherlands Institute of Ecology showed that global warming will lead to a dramatic loss of soil carbon to the atmosphere through the middle of the century. The lost soil carbon is expected to be equivalent of 12 to 17 percent of total human carbon emissions through 2050.

Global warming may affect the evaporation rate of water entering desert basins, increasing the amount of carbon that returns to the atmosphere rather than being absorbed by the desert soil, McNulty said.

Nonetheless, he said, desert basins are not well studied and amount to a significant storehouse of carbon.

“It’s part of the missing sink of carbon — that’s pretty important,” he said. “There’s a big chunk (of carbon) we haven’t figured out quite where it’s going.”

{like}

19 June 2017. Half of World Could See Deadly Heat Waves By 2100

Even with drastic cuts to the emissions of greenhouse gases that are driving up Earth’s temperature, more than half of the world’s population could be exposed to deadly heat waves by century’s end.

A tourist cools down at a fountain on a hot summer day in downtown Rome.
Credit: REUTERS

If emissions continue on their current path, that proportion will jump to three-quarters of the world’s residents, due to both rising temperatures and humidity, a new study detailed Monday in the journal Nature Climate Change, finds.

That future is what study author Camilo Mora calls a choice between “bad and terrible,” but crucially, it is still a choice. If the world reduces emissions, it can reduce the impacts of warming as much as possible.

Societies will also have to adapt to rising temperatures and the higher risks to human health they bring, but it is the developing countries that are least able to adapt that are likely to be hit the hardest.

“The projections of future risk to human health are sobering,” Michael Wehner, a senior staff scientist at Lawrence Berkeley National Laboratory who wasn’t involved in the study, said in an email, citing the particular risk to developing nations. “I welcome this paper for highlighting this inequity and for its novel demonstration that changes in the combination of heat and humidity are critical to understanding the effect of global warming on human health.”

A shift to more, and more extreme, heat is one of the clearest outcomes of global warming: as overall temperatures rise, extreme heat becomes more likely, and extreme cold less likely. Several studies have shown that warming is already influencing such heat waves.

{related}

Mora, a climate scientist at the University of Hawaii at Mona, and his colleagues wanted to see how various greenhouse gas emissions scenarios would affect the future occurrence of deadly heat waves, but found there wasn’t a good sense of how common they are now or over what threshold heat waves became deadly.

They pored over 30,000 studies and found nearly 800 cases of deadly heat events reported in 164 cities across 36 countries since 1980. “That was kind of exciting and scary at the same time to find so many of them,” Mora said.

From those historical events, the team found that the thresholds for deadly events varied from place to place based on the combination of temperature and humidity levels. Heat waves could lead to excess deaths at lower temperatures when humidity was sky high, as was the case during a 2010 Moscow heat event that killed thousands.

How the number of days of deadly heat will change under different scenarios of greenhouse gas emissions.
Credit: Mora, et al./Nature Climate Change

Humidity exacerbates the effects of high temperatures because it shuts down the body’s natural cooling system, preventing the evaporation of sweat.

Using historic data, the team found that 30 percent of the world’s population sees at least 20 days each year that surpass the temperature and humidity thresholds for a deadly event at a given location.

Under even the most stringent cuts to emissions — cuts that are virtually unfeasible at present — that proportion would increase to half by 2100. If emissions aren’t curtailed at all and continue to increase, 75 percent would be under threat.

In particular, New York City would see 50 days over the threshold considered deadly, while Los Angeles would see 30, and Orlando and Houston would be above those conditions for the entire summer under the latter scenario. The increase in deadly heat days for various cities can be seen in an interactive map the researchers put together.

Mora called the results “mind blowing” and said they underscore the need for global action to curtail emissions of carbon dioxide, the main greenhouse gas. Such action is under threat with President Trump’s announcement this month that he will pull the U.S. out of the landmark Paris accord, though some cities and states are looking to fill the gap left by the federal government.

Mora said that even though deadly heat events will rise under more moderate warming, the need for action was akin jumping from a building. “You either jump from the 4th floor or you jump from the 8th floor,” he said.

The biggest increases in potentially deadly heat were found, somewhat surprisingly, in the tropics, where many developing countries are. While this region won’t see the biggest increase in temperature, conditions are already so hot and humid that a small rise can tip them over the edge.

Of course, just because more heat events will surpass the deadly threshold, they won’t necessarily cause excess deaths, as society can adapt to hotter conditions. This is more likely to occur in developed countries, which have an edge because of more widespread access to air conditioning, clean water and quality health care.

Developing countries, though, often lack the resources to fund adaptation efforts. Some such countries are looking for ways to reduce deaths and illness associated with extreme heat, though; several cities in India are instituting heat health action plans to better warn residents of the risks of heat waves and have shown success in reducing deaths.

Mora hopes this study and others like it will show policymakers that they need to take action to curb warming, and the sooner the better. The best way to deal with the rise in deadly heat “is to prevent it from happening,” he said. “Let’s try not to let the lion out of the cage.”

{like}

18 June 2017. Houston Fears Warming Will Cause Catastrophic Flooding

By Tom Dart, The Guardian

Sam Brody is not a real estate agent, but when his friends want to move home they get in touch to ask for advice. He is a flood impact expert in Houston — and he has plenty of work to keep him busy.

The Texas metropolis has more casualties and property loss from floods than any other locality in the U.S., according to data stretching back to 1960 that Brody researched with colleagues. And, he said, “Where the built environment is a main force exacerbating the impacts of urban flooding, Houston is number one and it’s not even close.”

A road floods in Houston, Texas after rains from Hurricane Ike in 2008.
Credit: karllehenbauer/flickr

Near the Gulf Coast, Houston is also at annual risk from hurricanes: it is now into the start of the 2017 season, which runs from this month to November. Ike, the last hurricane to hit the Houston region, caused $34 billion in damage and killed 112 people across several states in September 2008.

There is little hope the situation is going to get better any time soon. Earlier this month, days after Donald Donald Trump announced the U.S. will withdraw from the Paris accord on climate change, a new report warned that rare U.S. floods will become the norm if emissions are not cut.

Brody, a professor in the department of marine sciences at Texas A&M University’s Galveston campus said the requests for help in Houston from people moving homes inspired him to create a forthcoming web tool so that people can type in an address and get a risk score.

“If you can see your crime statistics, shouldn’t you be able to see your flood risk also? And other risks as well, human-induced risks?” he said. The site will be named Buyers Be-Where.

In May 2015, eight people, many of them motorists, died in Harris County when a storm dropped 11 in of rain in parts of the city in 10 hours.

Last year, another six lost their lives in an April storm that hurled 240 billion gallons of water at the Houston area. An inch of rain fell over the county in only five minutes, with a peak of 16.7 in in 12 hours.

The events damaged thousands of homes, turning major freeways into canals and piling up vehicles as if they were in a junkyard. The 2016 flood cost an estimated $2.7 billion in losses and prompted more than 1,800 high water rescues.

Significant rains have always been a feature of life in south-east Texas. What bothers Brody and local environmentalists is the extent to which human activity is making things worse.

Flooding at a gas station in Houston, Texas.
Credit: Todd Dwyer/flickr

“Houston is situated in a low-lying coastal area with poorly draining soils and is subject to heavy rainfall events and storm surge events, which makes it very prone to flooding. And the climate is changing. In Galveston Bay the sea level is rising. We know the area is experiencing more heavy downpours,” Brody said.

“It pales in comparison with the other driving force, which is the built environment. If you’re going to put 4 million people in this flood-vulnerable area in a way which involves ubiquitous application of impervious surfaces, you’re going to get flooding.”

In other words: there is a lot of concrete in Houston. In 2000, 4.7 million people lived in the Houston metropolitan area. Now the population is about 6.5 million. While efforts are under way to densify and improve public transport in the urban core, much of the growth has been suburban, where houses are big and cheap and commuters drive long distances on some of the world’s widest freeways. The city keeps loosening its belt: a third ring-road cuts through exurbs some 30 miles from downtown, spurring more expansion.

To the west, idyllically named middle-class subdivisions sprout on former farmland, served by new retail complexes and multi-lane roads. Here, 3,500 square foot homes can be bought for less than $400,000, helping to explain the region’s population explosion. But it may be coming at a price — one paid downstream.

The Bayou City’s vein-like network of creeks and rivers are one of its defining features, but heavy rains turn them from subdued to seething. The Buffalo Bayou’s light brown waters meander 50 miles from west of the city through downtown to large bays in the east. The threat of catastrophic overflowing is mitigated by two dams built in the 1940s that the Army Corps of Engineers has classified as having an “extremely high risk” of failing and is now repairing.

The danger is lessened, too, by the natural defence of the western plains — but here, water-retaining grasses are being replaced by non-absorbent surfaces, which encourage water to travel downstream. Brody calculates that each new square metre of pavement in Houston on average adds $4,000 worth of flood damage.

Founded in 1992, the Katy Prairie Conservancy, a not-for-profit land trust, has a field office in bucolic land an hour’s drive from the skyscraping oil industry headquarters dotting central Houston. The Katy Prairie was once estimated at 500,000 to 750,000 acres, before Houston boomed. The Conservancy owns about 14,000 acres — an area roughly the size of Manhattan. It helps protect another 6,000, quietly working to shield fields from sprawl in a city and state better known for damaging the environment through oil and gas production than for preserving its natural resources.

“We may not be able to stop flooding but we ought to be able to better manage it,” said Mary Anne Piacentini, the executive director. “Our grasses are great water-holding reservoirs. Initial studies that we were doing with the Harris County Flood Control District show that our prairie grasses can hold up to about 8 in of water.”

Her colleague, Wesley Newman, likens tall grass prairies to an upside-down rainforest: the grass can grow to 6ft to 8ft above ground and two or three times as much below. “We’ve come to realise that the grassland, the tall grass prairie, is maybe even more important than the wetlands,” Piacentini said. “The more that we can restore, the more likely it is that we will be able to increase the water-holding capacity of what we do, and that affects directly downstream Houston.”

Inside Houston’s second ring road, 30 miles east, a photo album sat on a table in Dean Bixler’s living room. It was not filled with happy family portraits, but murky images of the flood-ravaged rooms of his house, with sofas elevated on chairs above coffee-coloured water.

The 60-year-old bought it in 1996, not imagining that his renovation budget would ever need to take the cost of pumps into account. Bixler said his house, built in 1960, has flooded three times since 2009, submerging his long front lawn and invading his home. “You could not see any grass. That’s a lot of frickin’ water,” Bixler said. In 2015, the repairs took about five months. In 2016, his flood-proofing measures kept water infiltration to an inch and a half.

Flooding closes a road in Texas.
Credit: meltedplastic/flickr

Bixler is a member of Residents Against Flooding, a group that last year filed a lawsuit against the city and a local infrastructure authority alleging that poorly mitigated developments are causing hundreds of homes to flood.

“The truth is that most of the flooding in Houston is manmade,” said Ed Browne, another member, pointing out that many people who get flooded, Bixler included, are not in the 100-year floodplain — an area calculated to have a 1 percent annual chance of flooding.

But Bixler’s part of town has in the past decade been extensively redeveloped, with new shopping malls, office blocks, homes and apartment complexes, many designed, critics say, with flood-control strategies such as elevation that appear to prioritise self-protection with little overall plan as to what happens to the diverted water.

It is a worrying vision of the future: stronger and more frequent storms with fewer natural barriers, while rapid and haphazard urban development with limited oversight creates new at-risk zones or worsens drainage in known problem areas.

The Harris County flood control district did not respond to requests for comment; its executive director, Russ Poppe, told the Houston Press last year that there are regulations to stop builders from increasing flood risks and that it is difficult to protect against exceptionally violent storms.

While residents battle for local improvements, there are predictions worthy of a disaster movie for what could happen if a powerful hurricane barrels directly into Houston’s industrial east. “If we get 20ft plus of water up the Houston Ship Channel it will be apocalyptic. I think all of us that have studied hurricanes are absolutely petrified about a big storm flooding the Houston Ship Channel and basically causing a number of those storage tanks to become unmoored and releasing their contents,” said Jim Blackburn, an environmental attorney and co-director of the Severe Storm Prediction, Education, and Evacuation from Disasters (SSPEED) Center at Rice University.

“There’s a lot of very dangerous materials that are generally handled, all things considered, fairly well, but they’re not designed against 20ft floods and if we have that it’s just going to be an incredibly bleak situation,” he said.

The coastal area from Galveston to Houston is home to several hundred thousand people, Nasa’s Johnson Space Center, the U.S.’s second-biggest seaport in terms of total tonnage, some of the nation’s largest refineries and its biggest petrochemical complex.

It is not lost on environmental activists that those refineries, as part of the fossil fuels industry, may be imperiled by extreme weather linked to climate change.

As a ProPublica/Texas Tribune investigation pointed out last year, had Ike been a little stronger and not changed course at the last minute in 2008, Blackburn’s nightmare scenario might have become reality.

According to the SSPEED Center, a 24 ft storm surge along the Ship Channel would cause about 90 million gallons of crude oil and chemical substances to rush into neighbourhoods and Galveston Bay — an event that a 2015 report claims “could easily become the worst environmental disaster in U.S. history”.

To say nothing of the economic impact on the region and the nation — a lengthy shutdown of south-east Texas’s facilities would be felt all over the country as products such as gasoline and jet fuel would become scarcer and more expensive.

A multibillion-dollar coastal barrier has long been on the wish list — but is far from being realized, since there is as of yet no consensus over the design, implementation and funding. “If you look historically at major hurricane enters Galveston Bay every 15-20 years, so it’s going to happen,” said Brody, the professor.

“It is something that keeps me awake at night every June that rolls around, hurricane season, because it’s not if, it’s just when — and every year we put more people and critical assets in harm’s way. We keep rolling the dice and the stakes become higher.”

Reprinted with permission from The Guardian.

17 June 2017. Scientists Saw a Nearly Unheard of Antarctic Meltdown

Antarctica is unfreezing. In the past few months alone, researchers have chronicled a seasonal waterfall, widespread networks of rivers and melt ponds and an iceberg the size of Delaware on the brink of breaking away from the thawing landscape.

A new study published in Nature Communications only adds to the disturbing trend of change afoot in Antarctica. Researchers have documented rain on a continent more known for snow and widespread surface melt in West Antarctica last summer, one of the most unstable parts of a continent that’s already being eaten away by warm waters below the ice.

Surface melt became widespread over West Antarctica in January 2016.
Credit: Nicolas et al,. 2017

The findings, published Thursday, indicate that last year’s super El Niño played a large role in driving the meltdown, but researchers are concerned that overlaying natural climate patterns onto the long-term warming driven by carbon pollution could put Antarctica’s ice in an even more precarious position.

“There’s a substantial loss of ice going on from warm water eating away at the bottom of some critical ice shelves,” David Bromwich, a climate modeler at Ohio State, said. “If we move into the future and we’ve got a lot of melting from the top as well, that means things would proceed even faster. It’s not a good prescription.”

{related}

The research, which Bromwich helped produced, stemmed from a series of coincidences starting at the top of the West Antarctic ice sheet, nearly 6,000 feet above sea level. Researchers stationed there in January 2016 noticed surface melt starting in the middle of the month and even reported seeing rain as warm, moist air poured into the region.

Bromwich said he had never heard of rain falling on that region of the ice sheet, though the Antarctic Peninsula further north will occasionally get a few showers. His and other researchers’ curiosity was piqued and using satellite imagery and high altitude balloon data, they were able to confirm the melt not just at the top of the ice sheet but across much of West Antarctica.

About 300,000 square miles of the ice sheet near the Ross Sea experienced melt, making it the second-largest surface melt ever documented in that region of Antarctica. The meltdown was caused by incredibly mild air. Temperatures spiked 27°F (15°C) above where they were at in early January in some locations, pushing them above freezing for a two-week period at lower elevations of the ice sheet.

The aurora australis over a West Antarctica research outpost.
Credit: AWARE

The biggest driver of the Antarctic heat wave was the super El Niño, then at its peak in the tropical Pacific. It helped rearrange the atmosphere so a high pressure system off Chile’s coast could steer abnormally balmy weather toward West Antarctica. The pattern has played out in other El Niño years, causing similar widespread melt events.

Ted Scambos, a researcher at the National Snow and Ice Data Center, said the study did a good job of explaining the mechanisms behind the meltdown and could be helpful in further understanding the forces at play in the region's climate.

The rain that preceded the major melt also may have also played a role in preconditioning the surface melt that Bromwich said was essentially a thick layer of slush covering the ice sheet.

What happened in West Antarctica last January was driven by natural climate shifts, but overlaying it on climate change is bad news for the region where ice shelves are melting from below.

Research has shown that those disappearing ice shelves could trigger “unstoppable” melt as warm water eventually pushes up under parts of the marine ice sheet itself, sending sea levels at least 10 feet higher. Surface melt events like the one Bromwich and his colleagues documented will only compound the speed at which the ice sheet melts.

Previous research has shown that the odds of a super El Niño like the one that boiled the ocean in 2015-16 are likely to double as the climate warms, further compounding the risk. There were also strong winds out of the west that helped blunt some of the melting in January 2016, but if the meteorological odds don’t line up in the future, the region could be in even deeper trouble.

“What this particular event reported in this paper means is that regardless of how strong the westerlies are, we’re likely to get widespread melting,” Bromwich said. “And if they’re weak, we’ll get extreme melting.”

{like}

17 June 2017. Global Power Sector Emissions to Peak in 2026

By Reuters

Global emissions of greenhouse gases from the power sector are expected to peak in 2026, but will still be some way above levels needed to limit temperature rises in line with the Paris climate agreement, research showed.

Overall, $10.2 trillion will be invested in new global power generation between 2017 and 2040, with renewable power sources such as wind and solar accounting for almost three quarters of that, a report by Bloomberg New Energy Finance (BNEF) said.

Steam and other emissions are seen coming from a power station in Wollongong, south of Sydney, Australia, Nov. 17, 2009.
Credit: REUTERS/Daniel Munoz/File Photo

By 2040, global emissions are expected to be 4 percent below 2016's levels, but an additional $5.3 trillion investment in renewable power would be needed by 2040 to keep rising global temperatures below 2 degrees Celsius (3.6 degrees Fahrenheit).

Under the 2015 Paris deal, more than 190 countries pledged to curb greenhouse gas emissions to keep planet-warming well below 2 degrees to stave off the worst effects of climate change.

The report said the costs of renewable power were expected to continue to fall, with the cost of solar tipped to fall by 66 percent by 2040.

The cost of offshore wind power is forecast to fall by 71 percent by 2040, helped in part by increased competition and economies of scale from larger projects and bigger turbines.

U.S. President Donald Trump said this month he would withdraw his country from the Paris Agreement, but the report said the move is unlikely to revive the U.S. coal industry.

Coal-fired power generation in the United States is expected to fall by 51 percent by 2040, with a 169 percent increase in renewable power helping to fill the void.

"The greening of the world's electricity system is unstoppable, thanks to rapidly falling costs for solar and wind power, and a growing role for batteries, including those in electric vehicles," said BNEF analyst Seb Henbest, the report's lead author. 

Homes and businesses with their own renewable generation sources, such as solar panels, are expected to be able to use and even sell the power they generate by storing it in batteries in their cars.

Electric vehicles and their batteries are forecast to account for 12-13 percent of electricity generation by 2040 in Europe and the United States, the report said.

Reporting by Susanna Twidale; Editing by Adrian Croft