25 August 2016 (350) – The seas of dead coral are a crime scene.
This year, the world witnessed the most devastating mass coral bleaching event ever recorded which left behind dead reefs in at least 38 countries. Many of these reefs will never recover.
The immediate cause is clear: the ongoing rise in global ocean temperatures that comes from climate change. But that’s like saying “he was killed by a bullet.” The important question is: who fired the gun?
We know who the biggest culprits are. For decades Exxon and their fossil fuel industry peers covered up how much they knew about climate change. #ExxonKnew the truth about the damage they were doing, but instead of telling the public, they chose to hide what they knew behind a campaign of lies and denial and robbed the world of a generation’s worth of time to reverse climate change.
It’s time for us to point the finger so that the world knows:
Exxon and their fossil fuel peers killed our reefs, and every day they continue to pollute they are knowingly putting our natural world — and all of us — in further danger.
How Exxon killed the reef
More than half a century ago Exxon's own scientists understood how much and how fast the world was going to warm from greenhouse gas emissions, and how much damage that was going to do.
What Exxon didn’t do was tell the rest of us. Instead, it — and many other players in the fossil fuel industry — bankrolled the rise of the climate denial industry. As a result, we’ve wasted a quarter century in a phony argument about whether the climate was changing. Time which could have prevented the deaths of our reefs and other devastating climate impacts.
What Exxon took from us: Great Barrier Reef, Australia
“The bleaching of the Great Barrier Reef is devastating to my whole community. The Gimuy Walubarra Yidinji have cared for this reef for thousands of years. It is a vital cultural and economic resource, not just for our people, but for all people. I ask that Exxon and the other fossil fuel companies think very carefully about what they are doing. They talk about denial, they pretend to argue about the science, but what’s really going on is a whole lot of greed. We don’t have time for their excuses now. That greed is driving our planet towards disaster. ”
— Associate Professor Henrietta Marrie, CDU, Gimuy Walubarra Yidinji elder, Cairns, Australia
Palolo Deep, Apia, Samoa
“2015 was the worst year ever experienced for bleaching in Samoa. In Palolo Deep, up to 10% of the reef died as a result of bleaching, while in some parts of Savai’i, 95% of the reef bleached. Normally bleaching occurs up to one or two meters but this year there was bleaching up to twenty, twenty five meters deep – I’ve never seen that happen before. Even some of the less susceptible corals such as the boulder corals were all bleached last year.”
— Samantha Kwan, Marine Conservation Officer, Ministry of Natural Resources and Environment
“The Andaman Islands are frequented by tourists from across the world and their main agenda is to experience the beautiful coral reefs. As the shallow sites are bleached out, the non-swimmer and first timers who make the major chunk of tourists here, are disappointed. They go back and communicate it to their circles and this leads to reduced diving activity and thus impacting the livelihood of many dive shops who earn money from this activity.”
— Subhash Chandran, SSI Dive Instructor, Andaman Islands, India
By James Hakner
22 August 2016
(University of Sussex) – A strong national commitment to nuclear energy goes hand in hand with weak performance on climate change targets, researchers at the University of Sussex and the Vienna School of International Studies have found.
A new study of European countries, published in the journal Climate Policy, shows that the most progress towards reducing carbon emissions and increasing renewable energy sources – as set out in the EU’s 2020 Strategy – has been made by nations without nuclear energy or with plans to reduce it.
Conversely, pro-nuclear countries have been slower to implement wind, solar and hydropower technologies and to tackle emissions.
While it’s difficult to show a causal link, the researchers say the study casts significant doubts on nuclear energy as the answer to combating climate change.
Professor Andy Stirling, Professor of Science and Technology Policy at the University of Sussex, said: "Looked at on its own, nuclear power is sometimes noisily propounded as an attractive response to climate change. Yet if alternative options are rigorously compared, questions are raised about cost-effectiveness, timeliness, safety, and security.
“Looking in detail at historic trends and current patterns in Europe, this paper substantiates further doubts.
“By suppressing better ways to meet climate goals, evidence suggests entrenched commitments to nuclear power may actually be counterproductive."
The study divides European countries into three, roughly equal in size, distinct groups:
- Group 1: no nuclear energy (such as Denmark, Ireland, and Norway)
- Group 2: existing nuclear commitments but with plans to decommission (e.g., Germany, Netherlands, and Sweden)
- Group 3: plans to maintain or expand nuclear capacity (e.g., Bulgaria, Hungary, and the UK)
They found that Group 1 countries had reduced their emissions by an average of six per cent since 2005 and had increased renewable energy sources to 26 per cent.
Group 2 countries, meanwhile, fared even better on emissions reductions, which were down 11 per cent. They grew renewable energy to 19 per cent.
However, Group 3 countries only managed a modest 16 per cent renewables share and emissions on average actually went up (by three per cent).
The UK is a mixed picture. Emissions have been reduced by 16 per cent, bucking the trend of other pro-nuclear countries. However, only five per cent of its energy comes from renewables, which is among the lowest in Europe, pipped only by Luxembourg, Malta, and the Netherlands.
The team say that the gigantic investments of time, money and expertise in nuclear power plants, such as the proposed Hinckley Point C in the UK, can create dependency and ‘lock-in’ – a sense of ‘no turning back’ in the nation’s psyche.
Technological innovation then becomes about seeking ‘conservative’ inventions – that is new technologies that preserve the existing system. This is, inevitably, at the expense of more radical technologies, such as wind or solar.
Professor Benjamin Sovacool, Professor of Energy Policy and Director of the Sussex Energy Group at the University of Sussex, said: "The analysis shows that nuclear power is not like other energy systems. It has a unique set of risks, political, technical and otherwise, that must be perpetually managed.
“If nothing else, our paper casts doubt on the likelihood of a nuclear renaissance in the near-term, at least in Europe."
Lead author Andrew Lawrence of the Vienna School of International Relations said: “As the viability of the proposed Hinkley plant is once again cast into doubt by the May government, we should recall that -- as is true of nuclear fallout -- nuclear power's inordinate expense and risks extend across national borders and current generations.
“Conversely, cheaper, safer, and more adaptable alternative energy sources are available for all countries.”
ABSTRACT: Since its initial adoption, the EU’s 2020 Strategy – to reduce its greenhouse gas emissions by 20%, increase the share of renewable energy to at least 20% of consumption, and achieve energy savings of 20% or more by 2020 – has witnessed substantial albeit uneven progress. This article addresses the question of what role nuclear power generation has played, and can or should play in future, towards attaining the EU 2020 Strategy, particularly with reference to decreasing emissions and increasing renewables. It also explores the persistent diversity in energy strategies among member states. To do so, it first surveys the current landscape of nuclear energy use and then presents the interrelated concepts of path dependency, momentum, and lock-in. The article proceeds to examine five factors that help explain national nuclear divergence: technological capacity and consumption; economic cost; security and materiality; national perceptions; and political, ideological and institutional factors. This divergence reveals a more general weakness in the 2020 Strategy’s underlying assumptions. Although energy security – defined as energy availability, reliability, affordability, and sustainability – remains a vital concern for all member states, the 2020 Strategy does not explicitly address questions of political participation, control, and power. The inverse relationship identified here – between intensity of nuclear commitments, and emissions mitigation and uptake of renewable sources – underscores the importance of increasing citizens' levels of energy policy awareness and participation in policy design.
Dead mussels ‘as far as the eye can see’ on Long Island Sound beach – ‘They’ve been hit with these consecutive heat waves that are just too hot for them’0 comments Posted by Jim at Monday, August 29, 2016
By Grant Parpan
24 August 2016
(Riverhead News Review) – David Gruner has been visiting the same private beach on the Long Island Sound in Jamesport for more than 50 years. On Wednesday afternoon, he witnessed something he’d never seen before.
When Mr. Gruner walked down to the beach he found the shoreline covered in mussels “as far as the eye can see.”
“They’re all about the same size, all clean shells,” he said. “It’s not like anything I’d ever seen growing on the Long Island Sound.”
In an email Wednesday evening, Bren Smith of Thimble Island Ocean Farm in Connecticut, the only mussel farmer on the Long Island Sound, said all his mussels are accounted for. He surmised the likely cause of such an occurrence would be “either extreme heat or a clam dredger ripped up a wild bed.”
“I suspect its the hot flash of water temps,” he said.
Mr. Smith pointed to a 2008 Staten Island Advance article announcing a similar “bizarre shellfish occurrence.” In that article, sources interviewed also blamed either a dredge boat or high temperatures.
Mr. Gruner, a Jamesport resident, estimated there are “hundreds of thousands” of mussels lining the shore between Iron Pier Beach in Jamesport and United Riverhead Terminal in Northville, about a 1.7-mile stretch of beach. He said the mussels were not there when he left the beach Tuesday afternoon, and guessed they’d come in with the high tide later that night. [more]
By Paul Squire
26 August 2016
(Riverhead News Review) – What caused thousands of blue mussels to appear along the shoreline in the Jamesport area this week hasn’t officially been determined. However, a local biologist believes the culprit may be rising water temperatures in the Long Island Sound.
“They’ve been hit with these consecutive heat waves that are just too hot for them,” said Christopher Gobler, the associate dean and researcher with the School of Marine and Atmospheric Sciences at Stony Brook.
State Department of Environmental Conservation officials concurred.
“It is likely that high water temperatures due to the prolonged hot temperatures we have experienced this summer is the cause,” DEC spokesperson Aphrodite Montalvo said.
The mussel die-off appeared Wednesday morning just east of Iron Pier beach and west of the oil terminal. Jamesport homeowner David Gruner said he and his wife noticed a rotting smell that morning and walked along the private beach to find thousands of mussels.
Mr. Gruner, a Jamesport native, said he’s never seen anything like the recent mussel die-off. […]
Mr. Gobler also said he believes long-term climate trends show warmer ocean temperatures may be here to stay since satellite readings of ocean temperatures by the National Oceanic and Atmospheric Administration dating back to 1982 show rising ocean temperatures.
“Eastern Long Island Sound and the Peconic stand out as a region that’s already experienced more rapid warming than a lot of the rest of the region,” he said. “It’s already an area that’s warming quickly.” [more]
The Anthropocene is here: Scientists recommend naming a new geological epoch as humans ‘permanently reconfigure Earth’s biological trajectory’0 comments Posted by Jim at Monday, August 29, 2016
29 August 2016 (AFP) – The human impact on Earth's chemistry and climate has cut short the 11,700-year-old geological epoch known as the Holocene and ushered in a new one, scientists said Monday.
The Anthropocene, or "new age of man," would start from the mid-20th century if their recommendation—submitted Monday to the International Geological Congress in Cape Town, South Africa—is adopted.
That approval process is likely to take at least two years and requires ratification by three other academic bodies.
But after seven years of deliberation, the 35-strong Working Group has unanimously recognised the Anthropocene as a reality, and voted 30-to-three (with two abstentions) for the transition to be officially registered.
"Our working model is that the optimal boundary is the mid-20th century," said Jan Zalasiewicz, a geologist at the University of Leicester.
"If adopted—and we're a long way from that—the Holocene would finish and the Anthropocene would formally be held to have begun."
Scientists refer to the period starting from 1950 as the "Great Acceleration", and a glance at graphs tracking a number of chemical and socio-economic changes make it obvious why.
Concentrations in the air of carbon dioxide, methane and stratospheric ozone; surface temperatures, ocean acidification, marine fish harvesting, and tropical forest loss; population growth, construction of large dams, international tourism—all of them take off from about mid-century.
One of the main culprits is global warming driven by the burning of fossil fuels.
A telltale surge in the spread of invasive plant and animal species is also a legacy of our species.
But the working group is not allowed to take any of these measures into consideration unless they show up in the geological record.
If it can't be measured in rocks, lake sediments, ice cores, or other such formations—the criteria used to determine dozens of distinct eons, era, periods and ages going back four billion years—it doesn't count.
This, however, is not a problem when it comes to the Anthropocene, said Zalasiewicz.
"We are spoiled for choice," he told AFP. "There's a whole array of potential signals out there."
Micro-plastics, for example—a synthetic, man-made substance—"are now components of sediment around the world, both in land and in the sea." [more]
By Paul Voosen
24 August 2016
(Science) – Just after World War II, when the atomic bombs fell and our thirst for coal and oil became a full-blown addiction, Earth entered the Anthropocene, a new geologic time when humanity’s environmental reach left a mark in sediments worldwide. That’s the majority conclusion of the Anthropocene Working Group, a collection of researchers that has spent the past 7 years quietly studying whether the term, already popular, should be submitted as a formal span of geologic time.
After tallying votes this month, the group has decided to propose the postwar boom of the late 1940s and early 1950s as the Anthropocene’s start date. The group will ask the International Commission on Stratigraphy (ICS), the bureaucracy that governs geologic time, to recognize the Anthropocene as a series, the stratigraphic equivalent of an epoch, on par with the Holocene and Pleistocene that preceded it. Colin Waters, the group’s secretary and a geologist at the British Geological Survey in Keyworth, will reveal the group’s recommendations on 29 August at the International Geological Congress in Cape Town, South Africa.
The group won’t submit a formal proposal yet. To do so, it must gather multiple cores of sediment from around the planet and show that they contain a sharp transition in geochemical tracers that is likely to persist as a permanent part of the rock record; the core with the best example of the transition would then serve as a “golden spike,” marking the Anthropocene’s start. These cores could come from lakebeds, ocean floors, ice sheets—or even corals or tree rings. But they must capture the “Great Acceleration”: the postwar period when fossil fuel combustion took off, says Jan Zalasiewicz, a geologist at the University of Leicester in the United Kingdom who convened the group. “We’ll go and get our hands dirty, beginning to look for sections that we can formally propose.”
Those sections will have to be rich with multiple signatures, as the Anthropocene proposal faces deep skepticism from stratigraphers. “The voting members of the International Commission on Stratigraphy look at these things critically,” says Stan Finney, chair of ICS and a geologist at California State University, Long Beach.
He and other stratigraphers doubt that their standards can be properly applied to decades-old mud and silt rather than the solid rock that records older stratigraphic boundaries. They question the value of the Anthropocene for their science, which seeks to draw coherent chronologies out of sedimentary rocks. Some also resent the role that scientists from other disciplines such as climate science have played in driving the proposal and see it as a political statement.
Should ICS decide against the Anthropocene, some stratigraphers fear, they could be swamped with bad press. “I feel like a lighthouse with a huge tsunami wave coming at it,” Finney says. Phil Gibbard, a stratigrapher at the University of Cambridge in the United Kingdom and a working group member who voted against the proposal, also worries about a backlash. “We’re nervous,” he says.
The working group, a mix of 35 geologists, climate scientists, archaeologists, and others, considered multiple dates. There were votes for an early start to the Anthropocene, 7000 years ago, when humanity began converting forests en masse to pastures and cropland, perhaps causing carbon dioxide (CO2) to spike, and also for 3000 years ago, when lead smelting tainted the ground. More recently, they considered 1610, when pollen from the New World appeared in Europe, and the early 1800s, the start of the Industrial Revolution. But the most votes went to the Great Acceleration.
The group’s decision to go for a single, recent start date for the Anthropocene disappoints Bill Ruddiman, an emeritus professor of environmental science at the University of Virginia in Charlottesville. “It is a mistake to formalize the term by rigidly affixing it to a single time,” he says, “especially one that misses most of the history of the major transformation of Earth’s surface.” Many archaeologists also favor the 7000-year-old date, when early humans began to alter the planet’s surface. But the working group was looking for a signature of global, human-driven change that would wind up in the rock record, not the first traces of human influence on the local landscape. [more]
Humans are altering the planet, including long-term global geologic processes, at an increasing rate. Any formal recognition of an Anthropocene epoch in the geological time scale hinges on whether humans have changed the Earth system sufficiently to produce a stratigraphic signature in sediments and ice that is distinct from that of the Holocene epoch. Proposals for marking the start of the Anthropocene include an “early Anthropocene” beginning with the spread of agriculture and deforestation; the Columbian Exchange of Old World and New World species; the Industrial Revolution at ~1800 CE; and the mid-20th century “Great Acceleration” of population growth and industrialization.
Recent anthropogenic deposits contain new minerals and rock types, reflecting rapid global dissemination of novel materials including elemental aluminum, concrete, and plastics that form abundant, rapidly evolving “technofossils.” Fossil fuel combustion has disseminated black carbon, inorganic ash spheres, and spherical carbonaceous particles worldwide, with a near-synchronous global increase around 1950. Anthropogenic sedimentary fluxes have intensified, including enhanced erosion caused by deforestation and road construction. Widespread sediment retention behind dams has amplified delta subsidence.
Geochemical signatures include elevated levels of polyaromatic hydrocarbons, polychlorinated biphenyls, and pesticide residues, as well as increased 207/206Pb ratios from leaded gasoline, starting between ~1945 and 1950. Soil nitrogen and phosphorus inventories have doubled in the past century because of increased fertilizer use, generating widespread signatures in lake strata and nitrate levels in Greenland ice that are higher than at any time during the previous 100,000 years.
Detonation of the Trinity atomic device at Alamogordo, New Mexico, on 16 July 1945 initiated local nuclear fallout from 1945 to 1951, whereas thermonuclear weapons tests generated a clear global signal from 1952 to 1980, the so-called “bomb spike” of excess 14C, 239Pu, and other artificial radionuclides that peaks in 1964.
Atmospheric CO2 and CH4 concentrations depart from Holocene and even Quaternary patterns starting at ~1850, and more markedly at ~1950, with an associated steep fall in δ13C that is captured by tree rings and calcareous fossils. An average global temperature increase of 0.6o to 0.9oC from 1900 to the present, occurring predominantly in the past 50 years, is now rising beyond the Holocene variation of the past 1400 years, accompanied by a modest enrichment of δ18O in Greenland ice starting at ~1900. Global sea levels increased at 3.2 ± 0.4 mm/year from 1993 to 2010 and are now rising above Late Holocene rates. Depending on the trajectory of future anthropogenic forcing, these trends may reach or exceed the envelope of Quaternary interglacial conditions.
Biologic changes also have been pronounced. Extinction rates have been far above background rates since 1500 and increased further in the 19th century and later; in addition, species assemblages have been altered worldwide by geologically unprecedented transglobal species invasions and changes associated with farming and fishing, permanently reconfiguring Earth’s biological trajectory.
These novel stratigraphic signatures support the formalization of the Anthropocene at the epoch level, with a lower boundary (still to be formally identified) suitably placed in the mid-20th century. Formalization is a complex question because, unlike with prior subdivisions of geological time, the potential utility of a formal Anthropocene reaches well beyond the geological community. It also expresses the extent to which humanity is driving rapid and widespread changes to the Earth system that will variously persist and potentially intensify into the future.
By Jeremy Hance
16 August 2016
(mongabay.com) – The Paris Agreement marked the biggest political milestone to combat climate change since scientists first introduced us in the late 1980s to perhaps humanity’s greatest existential crisis.
Last December, 178 nations pledged to do their part to keep global average temperatures from rising more than 2 degrees Celsius (3.6 degrees Fahrenheit) over preindustrial levels — adding on an even more challenging, but aspirational goal of holding temperatures at 1.5 degrees Celsius (2.7 degrees Fahrenheit).
To this end, each nation produced a pledge to cut it’s own carbon emissions, targeting everything from the burning of fossil fuels to deforestation to agriculture.
It seems like a Herculean task, bound, the optimistic say, to bring positive results.
Yet, less than eight months later, a study in the journal Nature finds that those pledges are nowhere near as ambitious as they need to be to keep temperatures below 2 degrees Celsius, let alone 1.5 degrees. And in August, British scientists reported that this year’s record El Niño has already pushed us perilously close to the 1.5 degree milestone.
Meanwhile, temperatures are not rising evenly around the planet, with the Arctic warming far faster than the tropics. That fact originally caused scientists to hypothesize that polar ecosystems would suffer more dire climate change impacts ahead of tropical habitats.
But over recent years, researchers began seeing that some tropical ecosystems are being decimated by climate change far faster than expected — think coral reefs — while many more habitats may be crippled over time — think mangroves, cloud forests and rainforests — if global human effort and political willpower don’t surge quickly.
Study leader, Joeri Rogelj, told Mongabay that he wasn’t surprised by his findings showing that current national carbon reduction pledges would blast past the 2 degree target, leading to global warming of between 2.6 degrees Celsius and 3.1 degrees Celsius.
“The pledges currently on the table are a first step in a continuous process of pledging, reviewing, and taking stock to what they add up,” said Rogelj, a Research Scholar at the Energy Program of the International Institute for Applied Systems Analysis (IIASA). “This process has been defined by the Paris Agreement, and nations are thus expected to review and adjust their pledges in light of the best science over the coming years.”
The Paris Agreement was structured from the bottom up, whereby national pledges would be reviewed every 5 years (beginning in 2020) in order to make sure that carbon cut targets are boosted as time goes by.
Still, Rogelj cautioned, if pledges aren’t sufficiently ramped up – and followed through on – it will make achieving the 2 degrees Celsius goal “significantly more ambitious” after 2030. […]
“We’re kidding ourselves that a 2 degree Celsius global increase will be safe for coral reefs and for the people who depend on them, given the damage we’re already seeing,” Terry Hughes bluntly stated in a Mongabay interview.
“Most reefs have already bleached three or more times in less than 20 years,” explained Hughes, who is the Director of the Australian Research Council (ARC) Centre of Excellence for Coral Reef Studies.
He points to his own country’s global warming-catastrophe: the Great Barrier Reef. Super-warm waters this year led to around half of the coral in the northern section of the Great Barrier Reef dying off. In some places, nothing is left but white coral ghosts. These massive changes came far earlier than were forecast by climate models. […]
Mark Urban, with the University of Connecticut, in a study last year looked at extinction risks for species linked to climate change. To get the best estimate possible, Urban analyzed findings from 131 studies.
He found that currently 2.8 percent of species face extinction due to climate change — this with a warming of around 0.9 degrees Celsius. If that warming jumps to the Paris pledged 2 degrees, extinction rates could rise to 5.2 percent of all species on the planet.
And if we hit 3.1 degrees Celsius this century, as projected by Joeri Rogelj’s study, which totaled up the current Paris pledges and the maximum temperature rise they could bring?
Then we could lose 9 percent of the world’s species due to global warming.
That’s nearly one-in-ten species facing extinction from climate change — and of course that doesn’t figure in extinction from other human induced threats like habitat degradation and destruction, deforestation, pollution, overharvesting, poaching, invasive species, or a lethal combination of any two or more of these combined with climate change. [more]
By Zeke Hausfather
23 August 2016
(Yale Climate Connections) – For the past century, coal has been king, providing the majority of U.S. energy for electricity generation.
But a combination of new federal and state environmental policies and a glut of cheap natural gas (mostly from hydraulic fracturing, or fracking) have led to a dramatic shift during the past decade, with coal dropping from 50 percent to 32 percent of our electricity generation and gas increasing from 18 percent to 33 percent.
Just under a third of existing coal-based power generation in the United States has been shut down, and the Obama administration has aggressively embraced the replacement of coal with gas as a key part of meeting its 2030 climate targets. We are quickly traveling down a gas bridge away from coal. But will this shift actually be a good thing for the climate? […]
How much methane leaks from the natural gas system is very much an open question. For a long time official Environmental Protection Agency numbers suggested the emissions were small and falling fast, only amounting to around 1.5 percent of total production.
But dozens of independent academics doing research using aircraft, satellite data, and other instruments have consistently found higher emissions than officially reported.
Adam Brandt at Stanford University published a high-profile paper in the journal Science in 2014 summarizing all the research to date. He found that overall emissions were likely between 25 and 75 percent higher than reported by EPA, suggesting that actual natural gas leakage rates are probably somewhere between 2 and 4 percent of gas production. (Some researchers have found leakage as high as 10 percent for individual fields, but there isn’t evidence that those findings are characteristic of the sector as a whole.) […]
If leakage is higher than 3 percent, there are some periods in the next 30 years when gas will result in more climate impact than new coal plants. If leakage is higher than 4 percent, there are some periods when gas will be worse for the climate than existing coal plants.
But no matter what the leakage rate is, gas will still cut the climate impact by 50 percent in 2100 compared to new coal and 66 percent compared to existing coal. So whether switching from coal to gas is beneficial in this simple example depends on how you value near-term or longer-term warming.
The importance of near-term warming is tough to assess. Climate models, by and large, don’t predict any irreversible changes in periods as short as 30 years, and potential tipping points in the climate generally depend more on the peak warming that occurs (which in nearly all foreseeable cases would occur after 2050). […]
Renewables are getting cheaper, and although it might not be practical to replace all coal plants with renewables immediately, it’s definitely possible to do so in the next decade if renewables continue to fall in price. If we replace coal with gas today, we’ve sunk costs into new gas infrastructure that we might be loath to replace a few years later with renewables. In this way, a gas bridge could delay the widespread adoption of renewables. [more]
By Andrew H. MacDougall
22 August 2016
(Nature Geoscience) – Between 17,500 and 14,500 years ago, a period sometimes referred to as the Mystery Interval1, atmospheric CO2 concentrations began their post-glacial rise from about 190 ppm in glacial times to approximately 270 ppm by the beginning of the Holocene. The rise in CO2 during the Mystery Interval is associated with large negative anomalies in the carbon isotopic composition of CO2 (refs 2,3). These anomalies suggest that a long-isolated carbon pool that was formed from a biological source was released to the atmosphere. A large pool of old 13C-depleted carbon in the Southern Ocean has been invoked as the source, but questions over the timing and magnitude of this release remain. Writing in Nature Geoscience, Crichton and colleagues5 report evidence from numerical simulations that suggest the primary source of the deglacial carbon during the Mystery Interval was instead a permafrost carbon pool.
Soil and bedrock that have temperatures below 0 °C for longer than two years are considered to be permafrost6. Permafrost soils hold an immense quantity of carbon in the form of partly decayed organic matter: carbon held in permafrost-affected soils is estimated to comprise ~35% of the total terrestrial carbon pool in the modern world7. Much of this carbon is held in permafrost soil horizons and is therefore frozen and protected from microbial decay7. Permafrost carbon — like all organic matter — has a low δ13C value and, because it can be locked in frozen soils for thousands of years, permafrost carbon typically has very little radiocarbon remaining6.
Extensive permafrost regions are thought to have existed during the Last Glacial Maximum. Under this cold climate, even though terrestrial productivity was half that of the pre-industrial period, the carbon pool housed in soils and vegetation was only ~10% smaller than that of the late Holocene8. However, the inactive fraction of the terrestrial carbon pool was about 45% larger than that of which exists today8. There is no palaeoclimate proxy to directly estimate the size of the permafrost carbon pool during the Last Glacial Maximum. Nonetheless, a large glacial permafrost carbon pool fits the criteria of a large inert carbon pool in a low primary productivity world.
Crichton and colleagues5 use an Earth system model of intermediate complexity to simulate the evolution of atmospheric CO2 concentration from the Last Glacial Maximum until the year 1850. In model simulations, the dissipation of the enhanced Southern Ocean carbon pool enlarges the atmospheric carbon pool by over 100 ppm of CO2 (red line, Fig. 1). However, the rise in CO2 concentrations occurs roughly 3,000 years after the rise observed in the ice-core record. Adding a permafrost carbon module to the Earth system model narrows the difference between the model simulation and palaeoclimate CO2 record, with simulated CO2 and δ13C closely matching the data until the onset of the Holocene (blue line, Fig. 1).
The simulations suggest a simplified storyline for the deglacial rise in atmospheric CO2. At the end of the Last Glacial Maximum, changes in Earth's orbit caused Northern Hemisphere summertime insolation to rise. These warmer summer conditions induced thaw of permafrost soils, which began to release long-sequestered carbon as CO2. The liberated permafrost carbon further warmed the climate, inducing deglaciation and further release of carbon from permafrost soils. Sea-level rise and a warming climate then triggered changes in brine formation and sinking in the Southern Ocean, which resulted in the dissipation of the glacial Southern Ocean carbon pool. However, regrowth of the terrestrial biosphere sequestered more carbon than was released from the terrestrial realm. Thus in net terms, although deglaciation was promoted by the release of permafrost carbon to the atmosphere, the ocean carbon pool was the dominant source of the glacial–interglacial rise in atmospheric CO2 concentrations. [more]
ABSTRACT: The atmospheric concentration of CO2 increased from 190 to 280 ppm between the last glacial maximum 21,000 years ago and the pre-industrial era1, 2. This CO2 rise and its timing have been linked to changes in the Earth’s orbit, ice sheet configuration and volume, and ocean carbon storage2, 3. The ice-core record of δ13CO2 (refs 2,4) in the atmosphere can help to constrain the source of carbon, but previous modelling studies have failed to capture the evolution of δ13CO2 over this period5. Here we show that simulations of the last deglaciation that include a permafrost carbon component can reproduce the ice core records between 21,000 and 10,000 years ago. We suggest that thawing permafrost, due to increasing summer insolation in the northern hemisphere, is the main source of CO2 rise between 17,500 and 15,000 years ago, a period sometimes referred to as the Mystery Interval6. Together with a fresh water release into the North Atlantic, much of the CO2 variability associated with the Bølling-Allerod/Younger Dryas period ~15,000 to ~12,000 years ago can also be explained. In simulations of future warming we find that the permafrost carbon feedback increases global mean temperature by 10–40% relative to simulations without this feedback, with the magnitude of the increase dependent on the evolution of anthropogenic carbon emissions.
In Latin America, environmentalists are an endangered species – ‘There is an increase in pressure to exploit resources that have not been exploited yet’0 comments Posted by Jim at Friday, August 26, 2016
By Lindsay Fendt
11 August 2016
(mongabay.com) – On a Tuesday in March, indigenous activist Nelson García was shot in the face in northwest Honduras. The next day, in Guatemala, unknown attackers found environmentalist Walter Méndez outside his home and filled his chest with bullets. Two weeks earlier gunmen killed Berta Cáceres, an internationally renowned environmental campaigner, in her Honduran home. And in the months before, similar killings were reported in Brazil, Mexico, and Peru.
Since 2010, murders over land disputes have been on the rise worldwide, but the problem is especially severe in Latin America, according to U.K.-based NGO Global Witness. The group documented more than 900 environmentalists killed in the region between 2002 and 2015. Last year was the deadliest year on record, with 185 murders worldwide, nearly two-thirds of them in Latin America, according to a report the group released in June.
“There is an increase in pressure to exploit resources that have not been exploited yet,” John Knox, a Special Rapporteur on human rights and the environment for the United Nations, told Mongabay. “You have very powerful economic interests on one hand and marginalized communities on the other and that seems to be leading to these conflicts [worldwide].”
Though in Latin America the reasons for the killings vary, many are related to a surge in development in remote parts of the region. Seeking out foreign investment, governments have been granting concessions to foreign-funded hydroelectric dams, mines, and other projects, often without consulting the communities already occupying the land. Meanwhile, landless ranchers, poachers, and illegal loggers are also pushing into remote areas in search of untapped resources.
Most of the encroached-upon areas have been inhabited by indigenous groups or subsistence farmers for generations, but many communities lack titles or deeds for their land. With little government assistance, some members of these communities are opposing environmental destruction on their own and paying the ultimate price.
“It is one of the most serious injustices in the world,” said Bill Kovarik, a professor at Radford University in Virginia who tracks murders of green activists. “For every one of these very serious deaths there are dozens of others that face violence.” [more]
By John Vidal
21 April 2016
(Guardian) – A documentary about the murder of a rainforest activist has been viewed tens of thousands of times online after being banned by the Cambodian government.
The film, I Am Chut Wutty, was due to be shown this week in a Phnom Penh cinema to coincide with the fourth anniversary of the killing of the environmentalist by an unidentified military police officer in April 2012.
But the Cambodian Department of Cinema and Cultural Diffusion refused the cinema a licence, stating that the British director had no permission to make the film.
The ban may have backfired, with sections of the Khmer language version of the film being viewed nearly 100,000 times in the last three days and private screenings reportedly being shown across Cambodia. An English version will be released next week.
Cambodian human rights and environment groups condemned what they said was suppression of the stories of people trying to save the country’s rainforest. [more]