Tuesday, December 01, 2020

The Limits of Clean Energy

Jason Hickel

The conversation about climate change has been blazing ahead in recent months. Propelled by the school climate strikes and social movements like Extinction Rebellion, a number of governments have declared a climate emergency, and progressive political parties are making plans—at last—for a rapid transition to clean energy under the banner of the Green New Deal.

This is a welcome shift, and we need more of it. But a new problem is beginning to emerge that warrants our attention. Some proponents of the Green New Deal seem to believe that it will pave the way to a utopia of “green growth.” Once we trade dirty fossil fuels for clean energy, there’s no reason we can’t keep expanding the economy forever.

This narrative may seem reasonable enough at first glance, but there are good reasons to think twice about it. One of them has to do with clean energy itself.

The phrase “clean energy” normally conjures up happy, innocent images of warm sunshine and fresh wind. But while sunshine and wind is obviously clean, the infrastructure we need to capture it is not. Far from it. The transition to renewables is going to require a dramatic increase in the extraction of metals and rare-earth minerals, with real ecological and social costs.

We need a rapid transition to renewables, yes—but scientists warn that we can’t keep growing energy use at existing rates. No energy is innocent. The only truly clean energy is less energy.

In 2017, the World Bank released a little-noticed report that offered the first comprehensive look at this question. It models the increase in material extraction that would be required to build enough solar and wind utilities to produce an annual output of about 7 terawatts of electricity by 2050. That’s enough to power roughly half of the global economy. By doubling the World Bank figures, we can estimate what it will take to get all the way to zero emissions—and the results are staggering: 34 million metric tons of copper, 40 million tons of lead, 50 million tons of zinc, 162 million tons of aluminum, and no less than 4.8 billion tons of iron.

In some cases, the transition to renewables will require a massive increase over existing levels of extraction. For neodymium—an essential element in wind turbines—extraction will need to rise by nearly 35 percent over current levels. Higher-end estimates reported by the World Bank suggest it could double.

The same is true of silver, which is critical to solar panels. Silver extraction will go up 38 percent and perhaps as much as 105 percent. Demand for indium, also essential to solar technology, will more than triple and could end up skyrocketing by 920 percent.

And then there are all the batteries we’re going to need for power storage. To keep energy flowing when the sun isn’t shining and the wind isn’t blowing will require enormous batteries at the grid level. This means 40 million tons of lithium—an eye-watering 2,700 percent increase over current levels of extraction.

That’s just for electricity. We also need to think about vehicles. This year, a group of leading British scientists submitted a letter to the U.K. Committee on Climate Change outlining their concerns about the ecological impact of electric cars. They agree, of course, that we need to end the sale and use of combustion engines. But they pointed out that unless consumption habits change, replacing the world’s projected fleet of 2 billion vehicles is going to require an explosive increase in mining: Global annual extraction of neodymium and dysprosium will go up by another 70 percent, annual extraction of copper will need to more than double, and cobalt will need to increase by a factor of almost four—all for the entire period from now to 2050.

The problem here is not that we’re going to run out of key minerals—although that may indeed become a concern. The real issue is that this will exacerbate an already existing crisis of overextraction. Mining has become one of the biggest single drivers of deforestation, ecosystem collapse, and biodiversity loss around the world. Ecologists estimate that even at present rates of global material use, we are overshooting sustainable levels by 82 percent.

Take silver, for instance. Mexico is home to the Peñasquito mine, one of the biggest silver mines in the world. Covering nearly 40 square miles, the operation is staggering in its scale: a sprawling open-pit complex ripped into the mountains, flanked by two waste dumps each a mile long, and a tailings dam full of toxic sludge held back by a wall that’s 7 miles around and as high as a 50-story skyscraper. This mine will produce 11,000 tons of silver in 10 years before its reserves, the biggest in the world, are gone.

To transition the global economy to renewables, we need to commission up to 130 more mines on the scale of Peñasquito. Just for silver.

Lithium is another ecological disaster. It takes 500,000 gallons of water to produce a single ton of lithium. Even at present levels of extraction this is causing problems. In the Andes, where most of the world’s lithium is located, mining companies are burning through the water tables and leaving farmers with nothing to irrigate their crops. Many have had no choice but to abandon their land altogether. Meanwhile, chemical leaks from lithium mines have poisoned rivers from Chile to Argentina, Nevada to Tibet, killing off whole freshwater ecosystems. The lithium boom has barely even started, and it’s already a crisis.

And all of this is just to power the existing global economy. Things become even more extreme when we start accounting for growth. As energy demand continues to rise, material extraction for renewables will become all the more aggressive—and the higher the growth rate, the worse it will get.

It’s important to keep in mind that most of the key materials for the energy transition are located in the global south. Parts of Latin America, Africa, and Asia will likely become the target of a new scramble for resources, and some countries may become victims of new forms of colonization. It happened in the 17th and 18th centuries with the hunt for gold and silver from South America. In the 19th century, it was land for cotton and sugar plantations in the Caribbean. In the 20th century, it was diamonds from South Africa, cobalt from Congo, and oil from the Middle East. It’s not difficult to imagine that the scramble for renewables might become similarly violent.

If we don’t take precautions, clean energy firms could become as destructive as fossil fuel companies—buying off politicians, trashing ecosystems, lobbying against environmental regulations, even assassinating community leaders who stand in their way.

Some hope that nuclear power will help us get around these problems—and surely it needs to be part of the mix. But nuclear comes with its own constraints. For one, it takes so long to get new power plants up and running that they can play only a small role in getting us to zero emissions by midcentury. And even in the longer term, nuclear can’t be scaled beyond about 1 terawatt. Absent a miraculous technological breakthrough, the vast majority of our energy will have to come from solar and wind.

None of this is to say that we shouldn’t pursue a rapid transition to renewable energy. We absolutely must and urgently. But if we’re after a greener, more sustainable economy, we need to disabuse ourselves of the fantasy that we can carry on growing energy demand at existing rates.

Of course, we know that poorer countries still need to increase their energy use in order to meet basic needs. But richer countries, fortunately, do not. In high-income nations, the transition to green energy needs to be accompanied by a planned reduction of aggregate energy use.

How might this be accomplished? Given that the majority of our energy is used to power the extraction and production of material goods, the Intergovernmental Panel on Climate Change suggests that high-income nations reduce their material throughput—legislating longer product life spans and rights to repair, banning planned obsolescence and throwaway fashion, shifting from private cars to public transportation, while scaling down socially unnecessary industries and wasteful luxury consumption like the arms trade, SUVs, and McMansions.

Reducing energy demand not only enables a faster transition to renewables, but also ensures that the transition doesn’t trigger new waves of destruction. Any Green New Deal that hopes to be socially just and ecologically coherent needs to have these principles at its heart.


This article was originally published on 6th September 2019 at Foreign Policy.
The Subterranean Brain of the Forest 
How Trees Communicate

Under the forest litter, trees build a network of connections that could be the envy of humans. It transports not only nutrients, but also information – about fires, droughts and environmental conditions. This speech of trees, and the relationships connecting them, were discovered by a certain persistent Canadian.











Daniel Mróz – drawing from the archives (no. 470–471/1954)


In one of the chapters of his book The Hidden Life of Trees, Peter Wohlleben gives a rather enigmatic description of how it was proved that various trees species can communicate. He doesn’t, however, refer us to the research. The secret behind that mysterious experiment is an extraordinary woman and her ground-breaking discoveries from 35 years ago, which permanently changed our perception of trees. They initiated a whole range of research regarding the symbiosis of trees and mushrooms at the Faculty of Forestry (University of British Columbia, Vancouver). On Polish Wikipedia, almost every other piece of information concerning mycorrhizal networks refers to the research co-authored by the Canadian. Recently she also inspired Richard Powers, author of the 2019 Pulitzer Prize-winning novel The Overstory. The writer used her biography to create the fictional character of the dendrologist Patricia Westerford.


Meet Suzanne Simard, who was the first to prove that trees communicate.

Simard – the granddaughter of a logger who ferried trees out of the forest using horses (which is still considered the best method for the ecosystem) – grew up in the woods of British Columbia, which take up 70% of this westernmost Canadian province. Canada has the third largest forest surface in the world, after Russia and Brazil. Incidentally, it’s worth knowing that more than half of the Earth’s forests grow in just five countries.

As a girl, Suzanne would lie down and watch the crowns of cedars, spruces and Douglas firs – some of the tallest trees in the world. Her playground was shaded by those giants. No wonder that she studied forestry, like her grandfather and uncles. However, she soon realized that her work contributes to the clearcutting of trees with industrial monster-machines which take seconds to topple a tree. She decided to leave the forest and return as a researcher.

At that time, a laboratory discovered that a pine root is able to send carbon to another root. Suzanne decided to check whether this also happens in a real forest. “Some people thought I was crazy, and I had a really hard time getting research funding. But I persevered,” she recalls in her TED Talk. The recording has been viewed more than a million times.

In a forest, Simard grew 80 young trees of three species: paper birch, Douglas fir and western red cedar. She covered the plants tightly with plastic bags, under which she pumped CO2 isotopes with huge syringes: the birch was surrounded by the radioactive isotope carbon-14; the fir with the stable carbon-13. After an hour, she took the bag off the birch and tested it with a Geiger counter. As expected, it beeped: the birch had absorbed the radioactive isotope. Simard approached the Douglas fir, removed the bag, moved the Geiger counter close and held her breath for a second. Then she heard the characteristic beeping again! Because both trees were covered with plastic foil, the radioactive carbon could have reached the Douglas fir only through the root system.

The counter’s buzz was evidence of the subterranean communication of trees. Simard reported: “The birch said: ‘Hey, can I help you with anything?’. And the fir said: ‘Yes, please, send me some carbon, because someone put a bag on me and I can’t photosynthesize.’.” Excited, she ran from one tree to the other, and each measurement confirmed her discovery. The Geiger counter was silent only at the western red cedar: those trees turned out to be disconnected from the network of birches and firs.

Soon various relationships started becoming apparent: the more shaded the fir was in the summer, the more carbon the birch sent it. But later, in autumn, the coniferous fir had a surplus of carbon, because it was still photosynthesizing, so it helpfully sent it to the birch, which was already losing leaves. “I knew I discovered something huge that would change the perception of trees in a forest: no longer as competitors, but also as collaborators. I found hard proof of a huge underground network of communication, a different world,” said the researcher.

This was 30 years ago. Since then, Simard and her team have published hundreds of papers. Thanks to them, we know more about what happens under the litter, where tree roots take up an area that can be many times the size of their crowns.
A network of relationships

Simard has a clear recollection of the moment when she understood that the forest is more than its visible, terrestrial part. She was with her grandfather at their allotment. Her dog fell into the hole under the outhouse, and grandpa started to dig next to it to save the animal. The young Suzanne saw twisted roots, white mycelium, reddish and greenish minerals. The dog was saved, and Suzanne became fascinated with the underground world.

Trees often connect directly via their roots, but the most important part of mass communication is played by fungi, which create so-called mycorrhizal networks. The toadstool-shaped mushrooms that we collect are just the fruiting bodies, the tips of icebergs: the vast majority of the fungus, its mycelium, extends underground and suffuses every bit of the surrounding soil. There are about 100 species of mycorrhizal mushrooms. Their hyphae create a network so dense that one tablespoon of soil could fit a few kilometres of it, and we could find a few hundred kilometres under a footprint. The mycelium works a bit like the internet; scientists have long been calling it the Wood Wide Web.

The fungus cells conduct barter with tree cells – fungi cannot photosynthesize, so they draw sugar from trees. They exchange it for nutrients, which they obtain from soil more successfully than trees. At the same time, they enable the transport of various other substances and communication. It’s not really clear why they throw in this latter service. Perhaps it is profitable to the fungus to have connections with many trees? Or maybe it’s that trees reduce the amount of sugar dispatched if the fungus does not allow them to connect with others?

What do trees give each other? It turns out that it’s not just carbon, but also phosphorus, nitrogen, water and information in the form of chemical and electric impulses. For example, they send warning signals about a pest attack, so that other trees can prepare and fend it off with defensive enzymes

At mother’s knee

The network created by fungi and trees has hubs and links. Hub trees or mother trees are the most important: the oldest and largest, connected with up to a few hundred other trees. They are the guardians of the sylvan community. They check in with their neighbours; share food and knowledge acquired throughout a long life. Thanks to the underground network, they send surplus carbon to young seedlings, which quadruples their chances of survival. What’s more, they can recognize their kin – they provide more food to youngsters with a similar genetic profile (although this doesn’t mean that they completely ignore seedlings unrelated to them). When mother trees get injured or are preparing to die, they bestow their wisdom on the next generations, especially those related to them. Although we don’t yet know which part of trees houses their memory, it definitely exists – the oldest trees remember bygone droughts and can adjust themselves and their environment to the changing climate. This is why in non-supervised forests, old stumps – which have no leaves, and hence no ability to photosynthesize – are still alive. Their neighbours nourish them via the underground pathway, because the knowledge those trunks have may be of use to surrounding plants. Tree stands behave like old human communities: they care both for the youngest members and the oldest, wisest ones.

“After years of work in the forest, I started to see what happens underground as the tree’s brain,” reveals Simard in a documentary entitled Intelligent Trees, where she speaks about her discoveries and observations along with Peter Wohlleben.

Priceless legacy

The dense underground network enables sylvan ecosystems to regenerate more easily and directly affects the health of the whole forest. This is why Suzanne does more than research. She also campaigns for balanced forest exploitation management, making use of ancestral wisdom and her own experiences as a forester.

Canada, so densely forested, also has one of the highest levels of tree cutting. Deforestation affects hydrological cycles, the distribution of gases and the lives of forest inhabitants. Seen from a satellite, large-scale clearcutting looks like bald spots left by alopecia, and it weakens the forest. The gaps are usually re-planted with just one tree species, frequently aspen or birch. Those forests are more prone to infections and more weakly communicated: the soil, damaged by huge machines, no longer transmits information, and there are no old trees around from which to learn. This means that a certain species of woodworm (Dendroctonus ponderosae) proliferates more freely in British Columbia than elsewhere, and there are unusually large fires. In 2014, more than three million hectares of forest burned down; it was the biggest fire in Canada’s Northwest Territories in 30 years.

Simard proposes a change in the way forests are managed. In her opinion, instead of clearcutting (completely cutting down patches of forest), it is better to leave behind a legacy: mother trees that are able to pass their knowledge on to new generations. “You can cut down one or two such trees, but there’s a critical moment: you cut down one too many and the whole system collapses,” she argues. Instead of planting one or two species, she recommends introducing diversity in new forests, and giving them time to establish their own order. She emphasizes that we need to save primaeval forests, as they are depositaries of genes. They no longer exist in Europe – apart from the Białowieża Forest in Poland. According to FAO (Food and Agricultural Organization of the United Nations), since 1990 we’ve lost 80 million hectares of this type of forest globally.

One of the oldest known trees, a Swedish spruce, is around 9500 years old. A healthy tree in a forest lives for around 400 to 500 years, if undisturbed. It has a chance to survive longer if it grows in a stand. Wohlleben writes that beeches which grow more densely – although they have small crowns and would seem to be rather uncomfortable – are healthier and more productive than the ones growing solo. Like people, trees growing in solitude usually have shorter lives, cut off from the live network of information and their care system.

In one of her interviews, Simard shared a personal story: “A few years ago I had breast cancer. Today I feel great. I survived it mainly thanks to my connections – the friendships I created. I felt that I’m experiencing what I study in forests. A tree is also going to be all right if only it stays a part of its own community.”

In writing this article, I used the following materials: a TED talk entitled “How trees talk to each other”, interviews with Suzanne Simard for the portal Yale Environment 360 and www.ttbook.org, the documentary “Intelligent Trees”, Peter Wohlleben’s book “The Hidden Life of Trees” and the article “It’s Not the Trees That Need Saving” at Earthisland.org.

Translated from the Polish by Marta Dziurosz

Jaguars robust to climate extremes but lack of food threatens species

Researchers track climate change scenarios for Amazonian wild cats

QUEENSLAND UNIVERSITY OF TECHNOLOGY

Research News

A new QUT-led study has found wild jaguars in the Amazon can cope with climate extremes in the short-term, but numbers will rapidly decline if weather events increase in frequency, diminishing sources of food.

Distinguished Professor Kerrie Mengersen and Professor Kevin Burrage led a team of researchers in a world-first investigation of the big cat's chances of survival.

The new research results have been published in Ecology and Evolution.

The jaguar (Panthera onca) is the dominant predator in Central and South America and is considered a near-threatened species by the International Union Conservation Nature.

Research main points: -

  • Results are concerning for future viability of jaguar populations in Peruvian Amazon.
  • Stochastic statistical temporal model of jaguar abundance considers six population scenarios and estimates of prey species.
  • Jaguar diet includes white lipped peccary, collared peccary, red brochet deer, white tailed deer, agouti, paca and armadillo.
  • Species exhibit some robustness to extreme drought and flood, but repeated exposure can result in rapid decline.
  • Predictions show species can recover- at lower numbers - if there are periods of benign climate patterns.
  • Modelling provides framework to evaluate complex ecological problems using sparse information sources.


CAPTION

Infographic describing QUT investigation on the impact of climate change on jaguars.

Professor Mengersen said the Pacaya Semiria Reserve covers 20,800 km2 in the Loreto region of the Peruvian Amazon, comprised of mostly primary forest.

"Estimates of jaguar numbers are difficult to achieve because the big cats are cryptic by nature, are not always uniquely identifiable, and their habitat can be hostile to humans," Professor Mengersen said.

The project drew on information gathered during a 2016 trip to the remote reserve, as well as a census study based on camera traps and scat analysis, jaguar ecology, and an elicitation study of Indigenous rangers in the Pacaya Samiria National Reserve.

Six jaguar population scenarios were analysed mapping the jungle creature's solitary behaviour, mating, births of cubs at certain times of the year, competition, illegal hunting, death from starvation and availability of key prey.

Professor Kevin Burrage cautioned the predicted results for the jaguars in the long-term were concerning.

"Our results imply that jaguars can cope with extreme drought and flood, but there is a very high probability that the population will crash if the conditions are repeated over short time periods. These scenarios are becoming more likely due to climate change," he said.

"The declines may be further exacerbated by hunting of both jaguars and their prey, as well as loss of habitat through deforestation."

Professor Burrage said scenario 1 estimated the jaguar population at 600-700 assuming stable prey availability while scenario 6 was an extreme case with drought and flood occurring every other year.

"In this worst-case scenario, prey levels could not recover, and jaguar populations was predicted to drop to single digits in 30 years' time," Professor Burrage said.


CAPTION

QUT's Distinguished Professor Kerrie Mengersen led a team of researchers in a world-first investigation of the big cat's chances of survival with the findings published in Ecology and Evolution.

In addition to Professors Mengersen and Burrage, researchers involved in the study included Professor Erin Peterson, Professor Tomasz Bednarz, Dr Pamela Burrage, Dr Julie Vercelloni and June Kim based at the ARC Centre of Excellence for Mathematical and Statistical Frontiers, and Dr Jacqueline Davis of the University of Cambridge and the Vrije Universiteit of Amsterdam.

A pdf of the journal paper is available.

Imagery available via Dropbox.

TPU scientists develop eco-friendly hydrogel for agriculture

TOMSK POLYTECHNIC UNIVERSITY

Research News

Scientists of Tomsk Polytechnic University, in cooperation with the Czech colleagues have developed a new hydrogel for agriculture. It is meant to retain moisture and fertilizers in soil. The difference of the new hydrogel from other formulations is that it is made entirely of natural components and degrades in soil into nontoxic products to humans, animals, and plants. The research results are published in the Journal of Cleaner Production (IF: 7, 246; Q1).

Hydrogels are used in agriculture and forestry to retain moisture in soil, which directly affects germination. They are also used in combination with fertilizers as hydrogels reduce volatilization of fertilizers and therefore control fertilizer release.

"Due to the hydrogels, plants require less watering and fertilization. On the one hand, it is important for fresh water conservation on the planet, on the other hand, it reduces the harmful effect of fertilizers to the soil. Most of the hydrogels available on the market are made of polyacrylamide and polyacrinolintrile. They are not fully biodegradable, that is why they are considered potential soil contaminants. Even though the components themselves are not toxic, their commercial formulations contain residual amounts of acrylamide, which is a neurotoxic and carcinogen substance. We used whey protein and alginic acid as primary components in our research work. These are affordable, natural and completely non-toxic components. This is the main advantage of our hydrogel," Antonio Di Martino, one of the article authors, associate professor of the TPU Research School of Chemistry & Applied Biomedical Sciences, says.

The process of obtaining the hydrogel suggested by the authors of the research is simple: the primary components must be mixed in a solution, dried, and compressed into a tablet. In contact with liquids, the substance swells and becomes gel-like.

"We also added urea in the mixture which is a well-known fertilizer. Over time, the hydrogel degrades in soil gradually and evenly releasing the fertilizer. Moreover, the hydrogel itself degrades into carbon and nitrogen over time, while nitrogen is a widely used macronutrient in agriculture and an essential structural material for plants. The laboratory experiments showed that the hydrogel can be used a few more times after a full release of moisture," Antonio Di Martino notes.

In the future, the scientists will continue experimenting and searching for new materials for a controlled application of fertilizers in soil.

###

The scientists from Tomas Bata University in Zlín (the Czech Republic), Dairy Research Institute (the Czech Republic), and Research Institute for Soil and Water Conservation (the Czech Republic) took part in the research project.

An escape route for seafloor methane

Leakage from frozen layers was a puzzle, but a new study shows how the potent greenhouse gas breaks through icy barriers.

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Research News

Methane, the main component of natural gas, is the cleanest-burning of all the fossil fuels, but when emitted into the atmosphere it is a much more potent greenhouse gas than carbon dioxide. By some estimates, seafloor methane contained in frozen formations along the continental margins may equal or exceed the total amount of coal, oil, and gas in all other reservoirs worldwide. Yet, the way methane escapes from these deep formations is poorly understood.

In particular, scientists have been faced with a puzzle. Observations at sites around the world have shown vigorous columns of methane gas bubbling up from these formations in some places, yet the high pressure and low temperature of these deep-sea environments should create a solid frozen layer that would be expected to act as a kind of capstone, preventing gas from escaping. So how does the gas get out?

A new study helps explain how and why columns of the gas can stream out of these formations, known as methane hydrates. Using a combination of deep-sea observations, laboratory experiments, and computer modeling, researchers have found phenomena that explain and predict the way the gas breaks free from the icy grip of a frozen mix of water and methane. The findings are reported today in the journal PNAS, in a paper by Xiaojing (Ruby) Fu SM '15, PhD '17, now at the University of California at Berkeley; Professor Ruben Juanes at MIT; and five others in Switzerland, Spain, New Mexico, and California.

Surprisingly, not only does the frozen hydrate formation fail to prevent methane gas from escaping into the ocean column, but in some cases it actually facilitates that escape.

Early on, Fu saw photos and videos showing plumes of methane, taken from a NOAA research ship in the Gulf of Mexico, revealing the process of bubble formation right at the seafloor. It was clear that the bubbles themselves often formed with a frozen crust around them, and would float upward with their icy shells like tiny helium balloons.

Later, Fu used sonar to detect similar bubble plumes from a research ship off the coast of Virginia. "This cruise alone detected thousands of these plumes," says Fu, who led the research project while a graduate student and postdoc at MIT. "We could follow these methane bubbles encrusted by hydrate shells into the water column," she says. "That's when we first knew that hydrate forming on these gas interfaces can be a very common occurrence."

But exactly what was going on beneath the seafloor to trigger the release of these bubbles remained unknown. Through a series of lab experiments and simulations, the mechanisms at work gradually became apparent.

Seismic studies of the subsurface of the seafloor in these vent regions show a series of relatively narrow conduits, or chimneys, through which the gas escapes. But the presence of chunks of gas hydrate from these same formations made it clear that the solid hydrate and the gaseous methane could co-exist, Fu explains. To simulate the conditions in the lab, the researchers used a small two-dimensional setup, sandwiching a gas bubble in a layer of water between two plates of glass under high pressure.

As a gas tries to rise through the seafloor, Fu says, if it's forming a hydrate layer when it hits the cold seawater, that should block its progress: "It's running into a wall. So how would that wall not be preventing it from continuous migration?" Using the microfluidic experiments, they found a previously unknown phenomenon at work, which they dubbed crustal fingering.

If the gas bubble starts to expand, "what we saw is that the expansion of the gas was able to create enough pressure to essentially rupture the hydrate shell. And it's almost like it's hatching out of its own shell," Fu says. But instead of each rupture freezing back over with the reforming hydrate, the hydrate formation takes place along the sides of the rising bubble, creating a kind of tube around the bubble as it moves upward. "It's almost like the gas bubble is able to chisel out its own path, and that path is walled by the hydrate solid," she says. This phenomenon they observed at small scale in the lab, their analysis suggests, is also what would also happen at much larger scale in the seafloor.

That observation, she said, "was really the first time we've been aware of a phenomenon like this that could explain how hydrate formation will not inhibit gas flow, but rather in this case, it would facilitate it," by providing a conduit and directing the flow. Without that focusing, the flow of gas would be much more diffuse and spread out.

As the crust of hydrate forms, it slows down the formation of more hydrate because it forms a barrier between the gas and the seawater. The methane below the barrier can therefore persist in its unfrozen, gaseous form for a long time. The combination of these two phenomena -- the focusing effect of the hydrate-walled channels and the segregation of the methane gas from the water by a hydrate layer -- "goes a long way toward explaining why you can have some of this vigorous venting, thanks to the hydrate formation, rather than being prevented by it," says Juanes.

A better understanding of the process could help in predicting where and when such methane seeps will be found, and how changes in environmental conditions could affect the distribution and output of these seeps. While there have been suggestions that a warming climate could increase the rate of such venting, Fu says there is little evidence of that so far. She notes that temperatures at the depths where these formations occur -- 600 meters (1,900 feet) deep or more -- are expected to experience a smaller temperature increase than would be needed to trigger a widespread release of the frozen gas.

Some researchers have suggested that these vast undersea methane formations might someday be harnessed for energy production. Though there would be great technical hurdles to such use, Juanes says, these findings might help in assessing the possibilities.

"The problem of how gas can move through the hydrate stability zone, where we would expect the gas to be immobilized by being converted to hydrate, and instead escape at the seafloor, is still not fully understood," says Hugh Daigle, an associate professor of petroleum and geosystems engineering at the University of Texas at Austin, who was not associated with this research. "This work presents a probable new mechanism that could plausibly allow this process to occur, and nicely integrates previous laboratory observations with modeling at a larger scale."

"In a practical sense, the work here takes a phenomenon at a small scale and allows us to use it in a model that only considers larger scales, and will be very useful for implementing in future work," Daigle says.

###

The research team included Joaquin Jimenez-Martinez at the Swiss Federal Institute of Aquatic Science and Technology; Than Phon Nguyen, William Carey and Hari Vinaswanathan at Los Alamos National Laboratory; and Luis Cueto-Felgueroso at the Technical University of Madrid. The work was supported by the U.S. Department of Energy.

Written by David L. Chandler, MIT News Office

Caribbean coral reefs under siege from aggressive algae

An aggressive, golden-brown, crust-like alga is rapidly overgrowing shallow reefs, taking the place of coral that was damaged by extreme storms and exacerbating the damage caused by human activity

CARNEGIE INSTITUTION FOR SCIENCE

Research News

IMAGE

IMAGE: ORANGE PEYSSONNELID ALGAL CRUSTS SPREADING OVER A LOBE OF ORBICELLA ANNULARIS AT 14-METER DEPTH ON THE TEKTITE REEF ON THE SOUTHERN SHORE OF ST. JOHN, U.S. VIRGIN ISLANDS. view more 

CREDIT: IMAGE COURTESY OF PETER EDMUNDS.

Baltimore, MD--Human activity endangers coral health around the world. A new algal threat is taking advantage of coral's already precarious situation in the Caribbean and making it even harder for reef ecosystems to grow.

Just-published research in Scientific Reports details how an aggressive, golden-brown, crust-like alga is rapidly overgrowing shallow reefs, taking the place of coral that was damaged by extreme storms and exacerbating the damage caused by ocean acidification, disease, pollution, and bleaching.

For the past four years, the University of Oxford's Bryan Wilson, Carnegie's Chen?Ming Fan, and California State University Northridge's Peter Edmunds have been studying the biology and ecology of peyssonnelid algal crusts, or PAC, in the U.S. Virgin Islands, which are out-competing coral larvae for limited surface space and then growing over the existing reef architecture, greatly damaging these fragile ecosystems.

"This alga seems to be something of an ecological winner in our changing world," described lead author Wilson, noting that the various other threats to coral communities make them more susceptible to the algal crusts.

Edmunds first took note of the crusts' invasive growth in the wake of category 5 hurricanes Irma and Maria when they were rapidly taking over spaces that had been blasted clean by the storms.

Corals are marine invertebrates that build large exoskeletons from which reefs are constructed. To grow new reef structures, free-floating baby corals first have to successfully attach to a stable surface. They prefer to settle on the crusty surface created by a specific type of friendly algae that grows on the local rocks. These coralline crustose algae, or CCA, acts as guideposts for the coral larvae, producing biochemical signals along with their associated microbial community, which entice the baby coral to affix itself.

What puzzled the researchers is that both the destructive PAC and the helpful CCA grow on rocks and create a crust, but PAC exclude coral settlement and CCA entices it. What drives this difference?

The team set out to determine how the golden-brown PAC affects Caribbean coral reefs, and found that the PAC harbors a microbial community that is distinct from the one associated with CCA, which is known to attract corals.

"These PAC crusts have biochemical and structural defenses that they deploy to deter grazing from fish and other marine creatures," explained Fan. "It is possible that these same mechanisms, which make them successful at invading the marine bio-space, also deter corals."

More research is needed to elucidate the tremendous success that the algal crusts are having in taking over Caribbean reef communities and to look for ways to mitigate the risk that they pose.

"There is a new genomic and evolutionary frontier to explore to help us understand the complexity of organismal interactions on the reef, both mutualistic and antagonistic," added Fan.

Edmunds concluded: "The coral and their ecosystem are so fragile as it is. They are under assault by environmental pollution and global warming. We have made their lives so fragile, yet they are sticking in there. And now this gets thrown into the mix. We don't know if this is the straw that breaks the camel's back, but we need to find out."

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This work was funded by a Long Term Research in Environmental Biology grant and a Rapid Response Research grant from the U.S. National Science Foundation.

Research was completed under permits issued by the Virgin Islands National Park.

The Carnegie Institution for Science (carnegiescience.edu) is a private, nonprofit organization headquartered in Washington, D.C., with three research divisions throughout the U.S. Since its founding in 1902, the Carnegie Institution has been a pioneering force in basic scientific research. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.

UN to issue first-ever global report on harmful algal blooms

After 7 years' work, 100+ experts in 112 countries deliver 1st global assessment of HABs, synthesizing three decades of data

UNESCO INTERGOVERNMENTAL OCEANOGRAPHIC COMMISSION

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IMAGE: MORE THAN 100 SCIENTISTS IN 112 COUNTRIES CONTRIBUTED TO A SYNTHESIS AND ANALYSIS OF HARMFUL ALGAL BLOOM DATA GATHERED FROM 1985 TO 2018 -- A FIRST-EVER BIG DATA APPROACH TO... view more 

CREDIT: MELVIL JAPAN

A seven-year analysis of almost 10,000 Harmful Algal Blooms (HAB) events worldwide over three decades will be published by the HAB Programme of UNESCO's Intergovernmental Oceanographic Commission.

More than 100 scientists in 112 countries contributed to the synthesis and analysis of HAB data gathered from 1985 to 2018 -- a first-ever big data approach to detecting changes in the costly phenomenon's global distribution, frequency, and intensity.

The authors detail the health and economic damages caused by harmful microalgae, including:

  • Bioaccumulation of toxins in seafood (the most dominant HAB problem, broken down by both region and by algae species)

  • Toxic or non-toxic microalgae blooms causing discoloured water, scum, mucilage or foam, harming tourism and/or fisheries

  • Mass fish kills, including in aquaculture operations

  • High biomass, causing closures of e.g. beaches or desalination plants

The researchers also examine whether and how rising marine resource exploitation and other factors affect HAB events.

The work assesses the occurrence of toxin-producing and other harmful microalgae, and the status and probability of change in HAB frequencies, intensities, and range resulting from environmental change at the local and global scale.

Publication of the key findings in a prominent journal will be followed by a complete set of 13 papers to be published in a special edition of Harmful Algae.

Databases mined

Thousands of microalgae species form the foundation of aquatic food chains, help control atmospheric CO2 levels, and produce roughly half of the world's oxygen.

The troublemakers are approximately 200 species that can produce potent toxins or cause harm through their sheer biomass, plus a similar number of non-toxic species that can harm fish gills, impair the beauty of the sea with strange colours, scums and foams, or deplete oxygen.

The study involved mining the global Harmful Algae Event Database (HAEDAT), consisting of 9,503 events with one or more impacts on human society, together with the Ocean Biodiversity Information System (OBIS), which contains 7 million microalgal records including 289,668 toxic algal species occurrences.

Due to differences in the levels of monitoring worldwide, trends within the HAEDAT database were examined regionally and corrected for sampling effort using OBIS phytoplankton species records as a proxy.

The work creates the first-ever baseline to facilitate future tracking and detection of changes in the world's HAB problems, and to help manage the problems in future.

Three key public databases

The Harmful Algal Event Database (HAEDAT, http://haedat.iode.org)

The only existing database of information about harmful algal events from around the world, summarized into 'events' associated with a management action or negative economic / ecological impact. Includes cases of non-toxic water discolorations, mucilage, anoxia or other damage to fish.

HABMAP-OBIS (http://www.iobis.org):

A database on the geographic range of harmful algal species

HAEDAT and OBIS are both components of the IOC International Oceanographic Data and Information Exchange Programme (IODE).

The IOC-UNESCO Taxonomic Reference List of Harmful Microalgae

Includes formally accepted names of 150+ planktonic or benthic microalgae that have been proven to produce toxins. The number of species in the list has doubled over the years.

The work will help future researchers determine:

    1. The distribution of HAB species, HAB events, and toxins globally

    2. How the geographic distribution, characteristic, frequency and intensity of HABs are changing and if these changes are attributable to global change

    3. How climate change and other factors alter the impacts of HABs -- on human health, ecosystems, economics, food and water security

With more than 100 expert contributors from 112 countries, the work is piloted by 18 principal authors from 14 countries (including two from Australia, two from France, three from the USA):

    · Gustaaf M. Hallegraeff, University of Tasmania, Australia

    · Donald M. Anderson, Woods Hole Oceanographic Institution, USA

    · Catherine Belin, IFREMER, France

    · Marie-Yasmine Bottein, Ecotoxicologie et Développement Durable expertise, France

    · Eileen Bresnan, Marine Scotland, UK

    · Mireille Chinain, Institut Louis Malardé-UMR241, Tahiti

    · Henrik Enevoldsen, Intergovernmental Oceanographic Commission of UNESCO, University of Copenhagen, Denmark

    · Mitsunori Iwataki, University of Tokyo, Japan

    · Cynthia H. McKenzie, Fisheries and Oceans Canada, Canada

    · Inés Sunesen, CONICET - UNLP, Argentina

    · Grant C. Pitcher, University of Cape Town, South Africa

    · Pieter Provoost, Intergovernmental Oceanographic Commission of UNESCO, Oostende, Belgium

    · Anthony Richardson, CSIRO Oceans and Atmosphere, and University of Queensland, Australia

    · Laura Schweibold, Institut Universitaire Européen de la Mer, France

    · Patricia A. Tester, Ocean Tester, USA

    · Vera L. Trainer, National Oceanic and Atmospheric Administration, USA

    · Aletta T. Yñiguez, University of the Philippines, Philippines

    · Adriana Zingone, Stazione Zoologica Anton Dohrn, Italy

"The most frequently asked questions about Harmful Algal Blooms (HABs) are if they are increasing and expanding, and what are the mechanisms behind observed trends," the authors say.

"Indeed a global expansion of HABs and its causes have long been debated. Eutrophication, human-mediated introduction of alien harmful species, climatic variability, and aquaculture have all been mentioned as possible causes of an expansion and intensification of HABs. Our research sheds an authoritative light on the problem and will help guide responses to it for decades to come."

The IOC Intergovernmental Panel on HABs began the Global HAB Status Report in 2013.

The work is linked with the International Panel on Climate Change (IPCC) reporting mechanism, which increasingly is focusing on the biological impacts of climate change.

IOC UNESCO project partners include the International Atomic Energy Agency (IAEA), the International Council for Exploration of the Sea (ICES), the North Pacific Marine Science Organization (PICES) and the International Society for the Study of Harmful Algae (ISSHA). The initiative receives financial support from the Government of Flanders/FUST-DIPS.

Interested media and other parties may apply for advance, embargoed access to the papers, approximately one week prior to publication. Please email tc@tca.tc with the subject line: Advance access, UN HAB report

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About the HAB Programme: https://bit.ly/3l44mUY

The Intergovernmental Panel on Harmful Algal Blooms (IOC-IPHAB), part of the Intergovernmental Oceanographic Commission of UNESCO, initiated the development of the Global HAB Status Report in Paris in April 2013, developed with the support of the Government of Flanders within the IOC International Oceanographic Data and Information Exchange (IODE) Programme, which manages both the Harmful Algae Event Data Base (HAEDAT) and the Ocean Biodiversity Information System (OBIS). Partners include ICES, PICES and IAEA.

OBIS focuses on the global distribution of all marine species including those HAB species that are toxic to humans and fish as covered by the IOC-UNESCO Taxonomic Reference list of Harmful MicroAlgae (a subset of the World Register of Marine Species), while HAEDAT holds information specifically on the HAB events that have adversely impact on human society, whether by high biomass (clogging of fishing nets, beach closures), aquaculture fish kills, or seafood toxin events leading to shellfish farm closures, human poisonings or even death.