Methane Reading August 21st, 2014

Best I can do without the methane tracker. Yellow can be seen in the Arctic Ocean, Alaska and Canada which is around 2000 ppb and above. - Harold H Hensel

Professor Peter Wadhams Discusses Subsea Permafrost Methane Releases And...

Dr Natalia Shakhova Interview: Part 1- Methane Hydrates & Stability of E...

Last Hours

Last Hours
Published on Sep 28, 2013
"Last Hours" is the first in a series of short films that explore the perils of climate change and the solutions to avert climate disaster. Each subsequent film will highlight fact-based challenges facing the human race, and offer solutions to ameliorate these crises. The initial short film series will culminate in a feature film to be presented prior to COP21, the 2015 UN Conference on Climate Change in Paris.

An asset for the climate change movement, "Last Hours" will be disseminated globally to awaken modern culture worldwide about the various dangers associated with climate change.

"Last Hours" describes a science-based climate scenario where a tipping point to runaway climate change is triggered by massive releases of frozen methane. Methane, a powerful greenhouse gas, has already started to percolate into the open seas and atmosphere from methane hydrate deposits beneath melting arctic ice, from the warming northern-hemisphere tundra, and from worldwide continental-shelf undersea methane clathrate pools.

Burning fossil fuels release carbon that, principally through greenhouse effect, heat the atmosphere and the seas. This is happening most rapidly at the polar extremes, and this heating has already begun the process of releasing methane. If we do not begin to significantly curtail the use of carbon-based fossil fuels, this freed methane threatens to radically accelerate the speed of global warming, potentially producing a disaster beyond the ability of the human species to adapt.

This first video is designed to awaken people to the fact that the earth has experienced five major extinctions in the deep geologic past -- times when more than half of all life on earth vanished -- and that we are now entering a sixth extinction. Industrial civilization with its production of greenhouse gases has the ability to trigger a mass extinction; in the extreme, it could threaten not just human civilization, but the very existence of human life on this planet.

The world community and global citizens urgently need to chart a path forward that greatly reduces green house gas emissions. To take action and follow the pathway to solutions to the climate crisis, you can explore this website and you can also sign-up for future updates. Thank you.

"Last Hours" is presented and narrated by Thom Hartmann and directed by Leila Conners. Executive Producers are George DiCaprio and Earl Katz. Last Hours is produced by Mathew Schmid of Tree Media Foundation, and was written by Thom Hartmann, Sam Sacks, and Leila Conners. Music is composed and performed by Francesco Lupica.

To Fight Climate Change, the Entire World Will Have to Eat Less Meat

To Fight Climate Change, the Entire World Will Have to Eat Less Meat
It will be impossible to reach U.N. temperature targets without reducing our intake of certain foods, researchers say.
JOHN METCALFE Mar 31, 2014 citylab.com

Serious about battling climate change? Then you might want to consider going vegetarian. That's because it's looking like world temperatures will continue to climb unless people stop chowing on so much meat and dairy, according to new research from Sweden.

The United Nations believes it's imperative to keep future warming from rising more than 2 degrees Celsius above pre-industrial levels. To meet that target, there will have to be a sharp decrease in greenhouse-gas emissions by the end of the century. Some of the reductions must come from the energy industry, and some must hail from the agricultural realm.

But with agriculture, it won't be enough to roll out "smarter" animal feeds and better methods of crop production, say scientists at the Chalmers University of Technology in Gothenburg. Rather, "reduced ruminant meat and dairy consumption will be indispensable for reaching the 2 °C target with a high probability, unless unprecedented advances in technology take place," they assert in a study in Climatic Change.

Here's the crux of their findings:

Emissions from agriculture threaten to keep increasing as global meat and dairy consumption increases. If agricultural emissions are not addressed, nitrous oxide from fields and methane from livestock may double by 2070. This alone would make meeting the climate target essentially impossible.

"We have shown that reducing meat and dairy consumption is key to bringing agricultural climate pollution down to safe levels," says Fredrik Hedenus, one of the study authors. "Broad dietary change can take a long time. We should already be thinking about how we can make our food more climate friendly."

Many in the agricultural industry are trying to cut emissions of nitrous oxide and methane (the latter being a mightily potent greenhouse gas). There's the general streamlining of processes to make meat and dairy production more efficient, for example. Then there are technical tweaks. One is occasionally draining the water from rice paddies, as microbes in flooded paddies generate a large amount of methane. Another is adding supplements to livestock feed to prevent the animals from belching so much. Gassy livestock is a serious atmospheric force; for instance, the fermentation taking place inside cows and sheep accounts for two-thirds of Australia's agricultural emissions.

The Swedish team thinks that if these improvements become widespread they will get us close to U.N. targets, but not quite there. They whipped up this graph to show how agricultural emissions are likely to change if conditions remain static (blue), if productivity and technical innovations are widely adopted (orange), and if technical measures are paired with a 75 percent reduction in meat-and-dairy eating across the globe. The gray line shows "how much total emissions must be reduced to meet the two degree target with large certainty," they say, and the "distance between the bars and the line shows the total possible magnitude of emissions from energy, transport, industry and deforestation":

But how do you stop an increasingly voracious planet from eating dairy and meat? It surely won't be enough to ask people to change their diets. One interesting possibility is tinkering with food economics. In a study published in December, scientists suggested reducing the global mass of 3.6 billion ruminants—which is 50 percent more than roamed the planet a half-century ago—by implementing some sort of tax-or-trade system. The Guardian explains:

The scientists' analysis, published in the journal Nature Climate Change, takes the contentious step of suggesting methane emissions be cut by pushing up the price of meat through a tax or emissions trading scheme.

"Influencing human behaviour is one of the most challenging aspects of any large-scale policy, and it is unlikely that a large-scale dietary change will happen voluntarily without incentives," they say. "Implementing a tax or emission trading scheme on livestock's greenhouse gas emissions could be an economically sound policy that would modify consumer prices and affect consumption patterns."

Obama Climate Rules Not Enough to Fight Global Warming

Obama Climate Rules Not Enough to Fight Global Warming
Climate change experts want more certain actions than are called for in the new proposed rule to cut carbon dioxide from power plants. Climate change is a global problem, and addressing it would require concerted action by all nations. Yet the EPA regulations are a step in the right direction. 

Gayathri Vaidyanathan, Jun 3, 2014 ClimateWire

If the measure of President Obama's proposed power plant regulations is their impact on climate change, they would be doomed to failure, according to climate scientists.

Under the U.S. EPA proposal, carbon emissions from the power generation sector would fall by 30 percent below 2005 levels. The reductions would be split among the states, with each state assigned a distinct target by EPA. The power sector contributes 40 percent of the greenhouse gas emissions of the United States, and coal-fired power plants are the sector's biggest emitters.

EPA's proposal is remarkable given the relative paralysis on climate action in Washington, but it would not budge the world's ever-rising emissions trajectory. That's because climate change is a global problem, and addressing it would require concerted action by all nations, heavy investments in carbon capture and sequestration (CCS) and near-zero emissions before 2050.

The new EPA rules as currently structured do not promote CCS and will likely shift the nation toward reliance on natural gas, which is also a greenhouse gas emitter, for power generation, cautioned Myles Allen, head of the Climate Dynamics Group at the University of Oxford.

The reason for climate scientists' pessimism is this: Carbon dioxide persists in the atmosphere for centuries, so today's emissions would trap heat at the Earth's surface well into the future. And at the rate we are emitting, the world would exceed the 2 degrees Celsius (3.6 degrees Fahrenheit) temperature change limit for 2100 that nations aspire to, according to climate models in the Intergovernmental Panel on Climate Change's (IPCC) fifth assessment report.

Curbing emissions from just coal-powered electricity, and in just one country, would not change that reality, said Michael Oppenheimer, a professor of geosciences and international affairs at Princeton University.

"Marginal cuts by the U.S. don't have a long-term overall big effect on the climate," he said. "What has to happen to have a big effect on the global climate is for all the big emitters to get together and decide that they are all going to cut some substantial fraction [of emissions]."

He said that global action, especially from developing nations such as China and India, could be more likely now that the U.S. has indicated its commitment to the problem. But observers of international treaty negotiations remain pessimistic about that prospect (ClimateWire, June 2).

A switch to natural gas won't do
Kenneth Caldeira, an atmospheric scientist at the Carnegie Institution for Science, said EPA's actions have to be the first step, and the agency needs to take similar steps every two years or so. And on top of that, the rest of the world needs to follow the United States' lead.

"But if this is the effort, and that is the end of it, then it's nowhere near the scale of what needs to be done," Caldeira said.

However, EPA's power plant regulations are likely the last major step toward achieving emissions reductions by 2020.

EPA is expecting some states to cut emissions by switching to natural gas for electricity generation, according to senior agency officials on a media briefing. Natural gas combined-cycle power plants are already heavily favored by utilities to the near exclusion of coal, said Joost de Gouw, an atmospheric scientist with National Oceanic and Atmospheric Administration's Cooperative Institute for Research in Environmental Sciences. On a per-megawatt basis, these plants emit just 40 percent of the emissions as coal-fired power plants.

But switching to natural gas for power generation does not solve the climate problem, scientists cautioned. Climate models in the IPCC's latest report indicate that to keep within the 2 C target by 2100, the world would have to emit close to zero, or even negative, quantities of greenhouse gases by 2050.

CCS, in which power plants trap carbon from flue gases and bury it underground, would be the only way to bring emissions to zero, Allen of Oxford said. The EPA proposal does not require CCS for either coal- or natural-gas-fired power plants.

Carbon capture is required
To ensure CCS development by 2050, EPA needs to regulate emissions from all fossil fuels—not just coal—today, Allen said. And immediate action is needed on CCS because any new power plants built now would still be operational in 2050. The energy system of the future would have to be implemented today.

"You would get exactly the same impact and guarantee a climate win, if instead of just targeting coal, the EPA would require a fraction of the carbon content of all forms of fossil energy should be sequestered," he said. "If they did that, job done."

Another potential problem with relying too much on natural gas is that the fuel is primarily made up of methane, a potent greenhouse gas. Studies have suggested that leaks of methane during production from oil and gas wells are so high that the fuel may be no better for the climate than coal. Research into the problem is ongoing.

The EPA-proposed rules apply to existing coal-fired power plants and would be implemented by executive order rather than as law. That means the rule could be changed by successive administrations, which creates regulatory uncertainty.

The rules may even be altered to allow coal back into the energy mix if the U.S. is faced with scarce resources, Allen said.

A step in the right direction?
"If the impact of these cuts is to mean the U.S. burns gas faster, and then goes back to burning its coal reserves in 2030, arguably it will make the problem worse," he said.

Richard Tol, a professor of economics at the University of Sussex, said the less permanent nature of executive orders can discourage investments in power plants, which are long-lasting infrastructure. He pointed to the United Kingdom, where long-term investments in power generation have stalled because climate and energy policy keeps changing "week to week."

"If you have a good reason to believe the rules of the game will change, then you are better off waiting and not investing," he said. "The next president may not agree with whatever Obama has done, and it creates an uncertainty that is very, very detrimental to investors."

Tol, at the same time, praised the EPA regulations as a step in the right direction. Given the humongous scope of the problem, action can seem beside the point, but "that creates a sense of defeatism right?" he said.

"If nobody does anything, then the problem will not go away," he said. "Every little bit will help."

Is it time we start saying the E word?

Is it time we start saying the E word?Pakalolo MAY 30, 2014

It is pretty good odds that a mass extinction is going on right now as you read this. This ticking time bomb proves that we are like insects, which live just a few days and will never experience changes in a season much less years. You and I will never know from experience the history of this planet. Much of that history is as abstract to us as the dimensions of the universe. Our planet is a complex, dynamic system that we probably will never fully comprehend. The Earth system, like the human body, comprises diverse components that interact in complex ways. The Earth's atmosphere, lithosphere, hydrosphere, cryosphere, and biosphere is a single connected system.

Extinction is a dire word for an extreme event. There has been five mass extinctions in our planets history due to either asteroid impacts, climate change caused by volcanism and the shifting of tectonic plates. The sixth mass extinction is being fueled by you and me. Mass extinctions are relatively short periods of history during which a significant quantity of species die off beyond the standard background extinction (normal process of a species dying out and is usually a natural occurrence).

Ordovician Silurian Extinction



The Ordovician Silurian Extinction was actually two extinction in close proximity that took place 440-450 million years ago, killing off over 60% of all marine species. Possible causes:

Weathering: heavy weathering of the Appalachian Mountains out-weighed volcanism, resulting in abnormally large CO2 sequestering, which lead to the development of a rapid ice age.

Gamma Ray Burst: this is a speculative hypothesis, but a gamma ray burst from a hypernova within 6,000 light years could have irradiated Earth. Within 10 seconds of the burst, half of the ozone layer would have been destroyed, bathing the planet in ultraviolet radiation.Late Devonian Extinction



A series of extinctions 360-375 million years ago, removed 70% of all species. Major environmental changes including frequent sea level changes, anoxic ocean bottoms, abnormally large carbon burials all contributed to the extinction; however it is not clear what caused the environmental changes in the first place. Possible causes:

Plant evolution - Devonian sough rapid evolution of plants, in the early Devonian the tallest plants were 30 cm but by late Devonian plants escalated to 30 m (90 feet). Archaeopteris forests quickly covered the globe.

Effect on weathering - these plants contributed to heavy weathering as plant roots broke up soil/rock releasing huge quantities of nutrients in to the rivers and the ocean, the ecology of the time was not able to absorb the nutrients subsequently leading to anoxia.

Effect on CO2 - the greening of the planet absorbed CO2 leading to a permanent chilling to the planet.Permian-Triassic extinction

The Permian-Triassic extinction, which took place 251.4 million years ago, was the Earth's largest, with 96% of all marine species and 70% of land species dying off. It's also the only known mass extinction of insects. Possible causes:

Methane Hydrate Gasification: the ocean sea-floor contains large amounts of methane hydrates, if those were to be released by a temperature change, the global temperature would increase by 6 degree Celsius (10.8F).

Flood Basalt Eruptions: Siberian Traps was one of the largest volcanic eruptions in Earth's history, with over 2 million square kilometers covered in lava.

Impact Event: Major asteroid collision with Earth has been proposed as a possible cause but no large impact crater has been located within the right time-period; however, if the asteroid impacted an ocean, the crater would have been destroyed by "conveyor belt" sea-floor spreading. The oldest sea-floor is only 200 million years old.Triassic-Jurassic Extinction



205 million years ago. 23%of all families and 48% of all genera went extinct. About half of the species o Earth were wiped out, including non-dinosaurian archosaurs (other than crocodiles), some therapids, and many large amphibians. Because of this, the reign of the dinosaurs officially began, most of their competition having been wiped out. This event happened fairly quickly on a geologic time scale (less than 10,000 years), right before the supercontinent Pangea began to break apart. There are several theories as to why this extinction happened, but nothing has been concretely found to determine the exact cause. The leading theories are gradual climate change, sea-level fluctuations, pulse of ocean acidity, asteroid impact, or massive volcanic eruptions (specifically from the Central Atlantic Magmatic Province, or CAMP). The reason could be any combination of these factors.Cretaceous Tertiary event



The Cretaceous Tertiary event, taking place 70-65 million years ago, killed off 75% of all species, including the dinosaurs. This extinction cleared the way for mammals and birds, where before dinosaur were the dominant land species. Avian dinosaur fossils are the only ones found after the K-T boundary. Possible causes:

Impact Event: an asteroid 10-15 km or 6-9 miles in diameter impacted Earth at Chicxulub, in Mexico's Yucatan Peninsula. The explosion would have been a billion times larger than the nuclear bomb dropped on Hiroshima.

Flood Basalt Eruption: Deccan Traps flood basalt erupted for 800,000 years during the K-T boundary period, it would have exacerbated the devastation caused by the asteroid impact and would have slowed down the recovery of organisms. An article from New Scientist reports on a study by Chris Thomas at the University of Leeds, UK, and colleagues, evaluating the impact on species of mild, moderate and severe levels of predicted climate change.

Mr. Thomas is quoted as saying: "The absolutely best case scenario - which in my opinion is unrealistic - with the minimum expected climate change and all of the species moving completely into new areas which become suitable for them, means we end up with an estimate of nine per cent facing extinction," This best case scenario means that 1 million species would go extinct assuming there are 10 million species in existence.

Many studies have looked at individual extinctions, while this study looks at migrations of species in a warming world. Thomas says the effects of climate change should be considered as great a threat to biodiversity as the "Big Three" - habitat destruction, invasions by alien species and overexploitation by humans.

Thomas states that his study overturns the belief that "climate change might simply result in the reassembling of species around the planet, without them dying out".

Thomas and colleagues around the world statistically modelled the climates in which each of the 1103 species considered currently live. Whole groups of plant and animal species confined to a particular region, for example, the Amazon, were evaluated.

Endangered species would have been included among these, as well as more common species, so Thomas says there is no reason to suppose that the organisms selected are unrepresentative of species generally.

The survival of each species was then modelled under the minimum, mid-range and maximum global warming scenarios predicted by the Intergovernmental Panel on Climate Change. Every species thrives best in certain conditions involving factors such as temperature and rainfall. So, Thomas says, the question was then: "Where are these same conditions going to be found?"

However, not all species would be physically able to migrate to new locations with equivalent conditions as the Earth hots up. And with lots of species, the models predicted that their new environment would be considerably smaller than their old habitats - a basic tenet of ecology is that smaller areas support fewer species.

Using the mid-range climate predictions, the researchers found that by 2050 between 15 and 37 per cent of the species would be on the "slippery slope" to extinction.
This study is probably conservative since the paper was published in 2004.

A very important video below.

“We’ve been talking about rising sea levels and extreme weather events,” said author Thom Hartmann. ”Now we need to talk about extinctions.”

Filmmaker Leila Conners and Producers George DiCaprio, Earl Katz, and Mathew Schmid have joined with Hartmann and writer/researcher Sam Sacks to produce a new short film – “Last Hours” – about the most extreme possible outcome of global warming.

Our planet has nearly died before. Five times in the deep geologic history of planet Earth, massive quantities of greenhouse gases have been released through the Earth’s crust. One was provoked by a meteorite strike, others by tectonic and volcanic activity. In each case, these massive releases of greenhouse gases warmed the planet enough to cause global mass extinctions – the death of more than half of all life.

“Last Hours” is a film that explores the possibility that we could be close – centuries or perhaps just decades -to tipping points that could lead to a sixth mass extinction, and relies on input from some of the world’s leading scientists.

The nail in our coffin? Methane.

Of the many tipping elements in the Arctic, that with potentially greatest consequences if perturbed is the vast methane deposit. Methane is a greenhouse gas. A molecule of methane has 20 times the greenhouse effect of a CO₂ molecule, and the release of methane has been linked to climatic transitions along the history of planet Earth.

The Arctic contains vast reserves of methane stored as methane hydrate, a gel-like substance formed by methane molecules trapped in frozen water. The methane hydrate deposits are estimated at between 1,000 and 10,000 Gigatons (109 tons) of CO₂-equivalents as methane, much of which is present in the shallow sediments of the extensive Arctic shelves. This amount of greenhouse gas is several times the total CO₂ release since the industrial revolution.

Even moderate (a few degrees C) warming of the overlying waters may change the state of methane from hydrates to methane gas, which would be released to the atmosphere. If this release is gradual, methane will add a greenhouse effect to the atmosphere. This will only be temporary, as it will be oxidised to CO₂, with a decline in the greenhouse effect of 20-fold per unit carbon.

However, if the state shift is abrupt it may lead to a massive release of methane to the atmosphere, which could cause a climatic jump several-fold greater than the accumulated effect of anthropogenic activity. Science Mag illustrates the venting of methane from the Siberian Eastern Shelf.

Remobilization to the atmosphere of only a small fraction of the methane held in East Siberian Arctic Shelf (ESAS) sediments could trigger abrupt climate warming, yet it is believed that sub-sea permafrost acts as a lid to keep this shallow methane reservoir in place. Here, we show that more than 5000 at-sea observations of dissolved methane demonstrates that greater than 80% of ESAS bottom waters and greater than 50% of surface waters are supersaturated with methane regarding to the atmosphere. The current atmospheric venting flux, which is composed of a diffusive component and a gradual ebullition component, is on par with previous estimates of methane venting from the entire World Ocean. Leakage of methane through shallow ESAS waters needs to be considered in interactions between the biogeosphere and a warming Arctic climate.A must see video below, have your medication of choice handy as you will need it. You can download google 3d imaging from You Tube or from Methane Tracker, but my pc would not allow me to do it. Skip to 3:09 as the scientists took a while getting the graphics up and running. This is absolutely bone chilling.

Video 1 of 2. This is a short intro to the Unified Methane Layers functionality on methanetracker.org.

Basically you're looking at two layers per day (0-12z and 12-24z) that contains only the methane over 1950ppb of all 100 layers from IASI for each (am and pm). Those two layers are shown at 6am (0-12z) and 6pm (12-24z) each day. The visualization using the Google Earth plugin allows you to pick a from and to data range that makes it easier to visualize the actual geographical scope of the venting episode, as well as identify specific geographic locations and dates to run a more detailed analysis using the "Individual Methane Layers" functionality.

Melting Polar Ice Caps A "Ticking Timebomb" For Earth's Climate System

Melting Polar Ice Caps A "Ticking Timebomb" For Earth's Climate System
TheRealNews Published on May 28, 2014

Journalist Dahr Jamail & Professor Peter Wadhams say the resulting release of methane will lead to massive climate disruption, and that we have reached a point of no return

Graphic: If we hit a climate-system tipping point because of methane, our carbon dioxide problem is immaterial

“We have to control methane immediately, and natural gas is the largest methane pollution source in the United States. If we hit a climate-system tipping point because of methane, our carbon dioxide problem is immaterial. We have to get a handle on methane, or increasingly risk global catastrophe.”

‘Catastrophe’ Claim Adds Fuel to Methane Debate

Excess methane is often burned off from oil and gas production and distribution systems.
Credit: Center for Enabling New Technologies Through Catalysis

‘Catastrophe’ Claim Adds Fuel to Methane Debate
Bobby Magill, May 15th, 2014 climatecentral.org

A Cornell University scientist's claims that oil and gas development is so harmful to the climate that methane emissions and oil and gas production in general need to be cut back immediately to avoid a "global catastrophe" are adding more fuel to the scientific debate over the climate implications of shale oil and gas production.

Fossil fuels production is the largest methane pollution source in the U.S., and ignoring those emissions will lead to a climate change “tipping point” from which there is no return, Cornell environmental biology professor Robert Howarth said in a statement Wednesday. He was unavailable for an interview.

Though scientists say there are avenues to preventing catastrophe other than curbing methane emissions, Howarth’s previous research with Cornell environmental engineering professor Anthony Ingraffea and others concluded that the climate impact of natural gas produced from shale — most of which involves hydraulic fracturing, or fracking — may be worse than that of coal and crude oil. That's because methane leaks from natural gas production have a greater effect on the climate than carbon dioxide emissions, Howarth said.

Over a 100-year timeframe, methane is about 34 times as potent as a climate change-driving greenhouse gas than carbon dioxide, and over 20 years, it's 86 times more potent. Of all the greenhouse gases released by humans globally, methane contributes more than 40 percent of all radiative forcing, a measure of trapped heat in the atmosphere and a measuring stick of a changing climate, Howarth said.

“We have to control methane immediately, and natural gas is the largest methane pollution source in the United States,” Howarth said. “If we hit a climate-system tipping point because of methane, our carbon dioxide problem is immaterial. We have to get a handle on methane, or increasingly risk global catastrophe.”

Howarth's research is controversial, with the energy industry trying to discredit his work and other scientists questioning his methods. Those questions come amid a steady stream of studies released over the past year that strongly suggest either that methane emissions emanating from oil and gas fields are greater than U.S. Environmental Protection Agency estimates or that the impact those emissions will have on climate change is extremely complex and difficult to determine. And even many scientists who agree with Howarth's research say there are other ways to curb methane emissions without shutting down natural gas production.

In other words, Howarth's critics say, methane's effect on the climate is too complicated to demand that emissions be cut dramatically and immediately.

Howarth's new paper, to be published May 20 in the journal “Energy Science and Engineering,” reviews much of the oil and gas-related methane emissions research conducted nationwide over the 4 years since his initial methane research was published in 2011, and in the context of the Intergovernmental Panel on Climate Change’s fifth assessment report released last year.

Howarth’s conclusion: Producing natural gas of any kind has a worse greenhouse gas footprint than burning coal and crude oil over a 20-year timeframe. In other words, the idea that natural gas is a “bridge fuel” between carbon-producing coal and clean renewable energy sources simply isn’t true, especially if natural gas is used for home heating, the study says.

At best, Howarth said natural gas might lead to a “very modest” reduction in greenhouse gas emissions if it is used in place of coal to generate electricity and only with “unprecedented” investment in natural gas infrastructure and regulatory oversight.

The paper is the latest in a long line of recent studies suggesting that methane emissions from shale oil and natural gas production and distribution equipment is much greater than previously thought.

A study by researchers from Purdue and Cornell universities published in April showed that natural gas drilling could emit up to 1,000 times the methane previously thought.

Just last week, the Cooperative Institute for Research in Environmental Sciences at the University of Colorado-Boulder released a study by National Oceanic and Atmospheric Administration atmospheric scientist Gabrielle Petron showing that an airplane flying over a large northeast Colorado shale oil and gas field measured atmospheric methane concentrations three times greater than U.S. Environmental Protection Agency estimates for the area.

EPA estimates are based on oil industry-reported data. In the EPA’s summary of its latest greenhouse gas emissions inventory, the agency cited one of Petron’s earlier methane emissions studies as evidence that the EPA’s industry-based methane estimates differ from the results of research that involves actual emissions measurements. The summary says the EPA “has engaged with researchers” on how measurements could improve understanding of inventory estimates.

“These discrepancies are substantial,” Petron said in a May 7 statement. “Emission estimates or ‘inventories’ are the primary tool that policymakers and regulators use to evaluate air quality and climate impacts of various sources, including oil and gas sources. If they’re off, it’s important to know.”

But different methods of measuring methane emissions get different results, and it's critical those differences be reconciled, said Robert Jackson, a professor of global environmental change at Duke University whose research has shown methane leaks are a hazard in natural gas distribution systems in the U.S.

By using an airplane to fly over an oil and gas field to directly measure methane concentrations in the air, Petron's study used a "top-down" approach to estimating oil and gas field emissions. Other scientists have used a "bottom up" approach by measuring emissions from oil and gas facilities on the ground, a method used in a University of Texas study published last year suggesting fracked natural gas wells leak less methane than the EPA previously estimated.

The simplest explanation for the discrepancy is that a few oil and gas wells emit a lot of methane, while others measured in "bottom up" studies release much less methane, Jackson said. Hundreds or thousands of wells would have to be sampled on the ground for the "bottom up" studies to accurately measure emissions, he said.

"The key point is the data that have come in in the last couple of years, it's not a huge dataset," Jackson said. "The data that have come in seem to suggest the EPA estimates are too low. Will they turn out that they're high enough that Bob Howarth is right? We don't know that yet, and it may not be the case."

The overall implications of natural gas production on a changing climate are extremely complicated, a Duke University study published in April by researchers Richard Newall and Daniel Raimi concluded.

Natural gas use can increase overall energy use and alter economy-wide greenhouse gas emissions, but it's unclear whether that means an increase or decrease in those emissions, and without specific emission targets, trends in atmospheric greenhouse gas emissions aren't likely to change even with widespread use of natural gas, Newall and Raimi conclude.

Howarth disagrees, saying there’s enough evidence that the climate implications of methane emissions from oil and gas development could be catastrophic and that it’s important to act now.

Crude oil tanks in northeast Colorado's suburban Wattenberg oil field, where measurements showed atmospheric methane concentrations were three times the levels reported in EPA inventories. Scientists say most of that methane came from the oil and gas operations in the area.
Credit: Bobby Magill
If shale oil and gas methane emissions aren’t reined in quickly, the earth could warm a critical 2°C within 15 to 35 years, he said. In order for the earth to avoid the most serious consequences of global warming, the planet’s average temperature cannot warm more than 2°C above where it was in the 1800s. Global average temperatures have already warmed 1°C.

Lawrence Cathles, a Cornell earth and atmospheric sciences professor whose criticism of Howarth's previous research made national headlines along with Howarth's rebuttal, said the science does not support Howarth's claim that immediate curbs on methane emissions are necessary to avoid the 2°C warming threshold.

"For methane to be a significant climate driver between now and 2035, its rate of increase in the atmosphere would need to accelerate dramatically, and so far we don't see this happening," Cathles said. "Curbs on methane emissions are desirable, but they will make a small player in climate change even smaller, and reducing emission rates below present levels is not a matter of necessity in controlling global warming."

Cathles said that substituting natural gas for coal in electricity generation would have an immediate benefit and methane leakage rates from natural gas systems would have to be much greater than they are now.

"My perception is that Howarth's views do not represent the views of most of the scientists that have considered these issues carefully, and that, contrary to the suggestions made in the subject paper, recent studies do not support the very high leakage rates he needs to make natural gas a 'bridge to nowhere.' "

Drew Shindell, a NASA Goddard Institute for Space Studies scientist on whose research Howarth draws but was not involved in Howarth's study, said that Howarth’s research is sound, but slashing methane emissions from natural gas isn’t the only way to keep global warming under 2°C.

Keeping the earth from warming will involve more than cutting carbon dioxide emissions alone or methane alone. Cutting a combination of some CO2, some methane, some black carbon and anything else that contributes to radiative forcing could keep warming down, too, Shindell said.

Regarding Howarth’s views denying that natural gas is a bridge fuel, Shindell said Howarth is pointing out that unless the methane leak rate from natural gas production and distribution is extraordinarily low, the reduction in greenhouse gas emissions compared to coal doesn’t exist.

If natural gas could be produced with the very lowest possible methane leak rate, natural gas might come out ahead of coal for greenhouse gases, Shindell said.

“Whether that’s feasible, I don’t know,” he said.

In his paper, Howarth is adamant that replacing climate-changing coal with climate-changing natural gas does nothing to slow global warming.

“Society needs to wean itself from the addiction to fossil fuels as quickly as possible,” Howarth said in a statement. “But to replace some fossil fuels — coal, oil — with another, like natural gas, will not suffice as an approach to take on global warming. Rather, we should embrace the technologies of the 21st century and convert our energy systems to ones that rely on wind, solar and water power.”

Jackson said he wouldn't quite go so far as to call for running away from natural gas.

"We need to do everything we can to cut methane emissions right now," Jackson said. "Using less natural gas might be one approach, but given that we are going to continue to use natural gas, my research (focuses on) how can we detect leaks quickly and fix them cheaply to reduce that leakage term?"

Shifting over completely to renewables would be great for human health and the environment, "but that's not the world we live in," Jackson said. "I want to know if you turn the spigot off for natural gas, do we get wind or do we get a new coal plant? And Bob (Howarth) might say that even if we got a coal plant, that's a good thing. It's not so black and white for me."

Control methane now, greenhouse gas expert warns

Photo of landfill burn off flare. Credit: Eddie Hagler/Public Domain

Control methane now, greenhouse gas expert warns
Blaine Friedlander (Phys.org) 

As the shale gas boom continues, the atmosphere receives more methane, adding to Earth's greenhouse gas problem. A Cornell ecology professor fears that we may not be many years away from an environmental tipping point – and disaster.

"We have to control methane immediately, and natural gas is the largest methane pollution source in the United States," said Robert Howarth, the David R. Atkinson Professor of Ecology and Environmental Biology, who explains in an upcoming journal article that Earth may reach the point of no return if average global temperatures rise by 1.5 to 2 degrees Celsius in future decades. "If we hit a climate-system tipping point because of methane, our carbon dioxide problem is immaterial. We have to get a handle on methane, or increasingly risk global catastrophe."

Howarth's study, "A Bridge to Nowhere: Methane Emissions and the Greenhouse Gas Footprint of Natural Gas," will be published May 20 in the journal Energy Science and Engineering.

Natural gas – that once seemingly promising link between the era of oil and coal to the serenity of sustainable solar, wind and water power – is a major source of atmospheric methane, due to widespread leaks as well as purposeful venting of gas. Howarth points to "radiative forcing," a measure of trapped heat in Earth's atmosphere from man-made greenhouse gases. The current role of methane looms large, he says, contributing over 40 percent of current radiative forcing from all greenhouse gases, based on the latest science from the Intergovernmental Panel on Climate Change.

The role of methane as a driver of global warming is even more critical than this 40 percent value might indicate, Howarth notes. The climate system responds much more quickly to reducing methane than to carbon dioxide. If society aggressively controlled carbon dioxide emissions, but ignored methane emissions, the planet would warm to the dangerous 1.5 to 2.0 degree Celsius threshold within 15 to 35 years. By reducing methane emissions, society buys some critical decades of lower temperatures.

"Society needs to wean itself from the addiction to fossil fuels as quickly as possible," Howarth said. "But to replace some fossil fuels (coal, oil) with another (natural gas) will not suffice as an approach to take on global warming. Rather, we should embrace the technologies of the 21st century and convert our energy systems to ones that rely on wind, solar and water power."

In 2011, Anthony Ingraffea, Cornell's Dwight C. Baum Professor of Engineering; Renee Santoro, research technician in ecology and evolutionary biology; and Howarth published "Methane and the Greenhouse-Gas Footprint of Natural Gas from Shale Formations," in Climate Change Letters, where they explained that extracting natural gas from the Marcellus Shale will aggravate global warming more than mining and burning coal.

In this latest work, Howarth said that societies have run out of time and must pursue technological changes for sustainable energy now. "If we can control the methane, we have a chance to reverse course," he said.

Graphic: Methane Levels

Arctic Methane Emissions ‘Certain to Trigger Warming’

Arctic Methane Emissions ‘Certain to Trigger Warming’ (via Climate Central)

By Bobby Magill Follow @bobbymagill As climate change melts Arctic permafrost and releases large amounts of methane into the atmosphere, it is creating a feedback loop that is "certain to trigger additional warming," according to the lead scientist…

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Methane 1950 ppb

I am reminding people that the emissions are continuing and not slowing down. Methane in red is 1950 ppb and above. The first image is 04/01/2014. The second image is from Feb. 20th, 2014. The third image is an overlay for perspective. A lot of heat trapping methane is coming up from Antarctica. Pre industrial methane was 750 ppb. 1250 ppb is considered "livable". These numbers are way out of range for the earth's climate to stay in balance and for Antarctica to maintain stability. - Harold H Hensel

Wetlands likely to blame for atmospheric methane increases: Study

Wetlands likely to blame for atmospheric methane increases: Study
April 28, 2014 sciencedaily.com

A surprising recent rise in atmospheric methane likely stems from wetland emissions, suggesting that much more of the potent greenhouse gas will be pumped into the atmosphere as northern wetlands continue to thaw and tropical ones to warm, according to a new international study led by a University of Guelph researcher.

The study supports calls for improved monitoring of wetlands and human changes to those ecosystems -- a timely topic as the Intergovernmental Panel on Climate Change prepares to examine land use impacts on greenhouse gas emissions, says Prof. Merritt Turetsky, Department of Integrative Biology.

Turetsky is the lead author of a paper published today in Global Change Biology based on one of the largest-ever analyses of global methane emissions. The team looked at almost 20,000 field data measurements collected from 70 sites across arctic, temperate and tropical regions.

Agnieszka Kotowska, a former master's student, and David Olefeldt, a post-doc at Guelph, also were among 19 study co-authors from Canada, the United States, the United Kingdom, Finland, Germany and Sweden.

One of the strongest greenhouse gases, methane comes from agriculture and fossil fuel use, as well as natural sources such as microbes in saturated wetland soils.

The amount of atmospheric methane has remained relatively stable for about a decade, but concentrations began to rise again in 2007. Scientists believe this increase stems partly from more methane being released from thawing northern wetlands.

Scientists have assumed that wetland methane release is largest in the tropics, said Turetsky.

"But our analyses show that northern fens, such as those created when permafrost thaws, can have emissions comparable to warm sites in the tropics, despite their cold temperatures. That's very important when it comes to scaling methane release at a global scale."

The study calls for better methods of detecting different types of wetlands and methane release rates between flooded and drained areas.

Fens are the most common type of wetland in Canada, but we lack basic scientific approaches for mapping fens using remote sensing products, she said.

"Not only are fens one of the strongest sources of wetland greenhouse gases, but we also know that Canadian forests and tundra underlain by permafrost are thawing and creating these kinds of high methane-producing ecosystems."

Most methane studies focus on measurements at a single site, said co-author Narasinha Shurpali, University of Eastern Finland. "Our synthesis of data from a large number of observation points across the globe is unique and serves an important need."

The team showed that small temperature changes can release much more methane from wetland soils to the atmosphere. But whether climate change will ramp up methane emissions will depend on soil moisture, said Turetsky.

Under warmer and wetter conditions, much more of the gas will be emitted. If wetland soils dry out from evaporation or human drainage, emissions will fall -- but not without other problems.

In earlier studies, Turetsky found drying peatlands can spark more wildfires.

Another study co-author, Kim Wickland, United States Geological Survey, said, "This study provides important data for better accounting of how methane emissions change after wetland drainage and flooding."

Methane emissions vary between natural and disturbed or managed wetlands, says Wickland, who has helped the IPCC improve methods for calculating greenhouse gas emissions from managed wetlands.

Turetsky holds a Canada Research Chair in Integrative Ecology. She and her students examine how ecosystems regulate climate in field sites in Canada and Alaska.

Journal Reference:
Merritt R. Turetsky, Agnieszka Kotowska, Jill Bubier, Nancy B. Dise, Patrick Crill, Ed R. C. Hornibrook, Kari Minkkinen, Tim R. Moore, Isla H. Myers-Smith, Hannu Nykänen, David Olefeldt, Janne Rinne, Sanna Saarnio, Narasinha Shurpali, Eeva-Stiina Tuittila, J. Michael Waddington, Jeffrey R. White, Kimberly P. Wickland, Martin Wilmking. A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands. Global Change Biology, 2014; DOI: 10.1111/gcb.12580

BBC Earth Power of the Planet 2 - Atmosphere

BBC Earth Power of the Planet 2 - Atmosphere
Published on Apr 21, 2013
Earth: The Power of the Planet is a British documentary television series that premiered on BBC Two on 20 November 2007. The five-part series is presented by geologist Iain Stewart. In the United States, the series was broadcast on the National Geographic Channel as Earth: The Biography.

Human extinction: is it possible?

An artist's rendition shows lightning striking the surface of planet Venus. Could Earth end up being as inhospitable toward life as Venus? Photo: European Space Agency

Human extinction: is it possible?
Julian Cribb, April 2, 2014 smh.com.au

Over the Earth’s history, about 99.9 per cent of all species to emerge have gone extinct. Many humans, however, cherish a notion that this doesn’t apply to us.

Typically, species survive for about 10 million years before they succumb to Mr Darwin – though there are notable long-distance champions, like sharks (420 million years), jellyfish (550 million years) and algae (2+ billion years). In evolutionary terms this means the human race is barely out of the starting blocks compared with these venerable competitors, having so far successfully covered less than a tenth of the standard course.

In recent years a number of prominent figures have warned of the possibility of human extinction as a result of man-made climate change. (I use the term "man-made" advisedly, as most of the people who excavate carbon for a living are males. Climate change is a gender issue too.) How could it come about that a species so intelligent, flexible and well-equipped could potentially destroy itself? Surely, it must be grand hype?

Jellyfish have existed on Earth for 550 million years.

Well, no. Not really. But extinction theory doesn’t depend entirely on climate change, at least in the first instance; rather, it depends on human behaviour and our response to peril.

The idea that man-made carbon emissions could trigger catastrophic global warming is based on two particular facts:

1. The fact that it has happened before, about 50 million years ago during an event called the Palaeocene-Eocene Thermal Maximum, PETM for short, when the Earth’s temperature increased by at least 5 degrees, and possibly as much as 9 or 10 degrees. This lasted about 200,000 years. The icecaps vanished, the oceans warmed as high as 35 degrees, corals almost disappeared. PETM was probably driven or accelerated by a vast release of seabed methane – a greenhouse gas more than 20 times more potent than CO2. Although PETM caused a severe setback to life in general, it wasn’t as bad as the KT extinction which occurred about 10 million years earlier and removed the dinosaurs.

2. The fact that there are vast stores of methane in the Arctic permafrost and as frozen gas deposits on the sea bed, known as clathrates or gas hydrates. These are basically the accumulated detritus from billions of years of decomposition of dead organisms – plants, animals and algae. Clathrate deposits are estimated at between 500-2400 billion tonnes of methane – or around three times the size of the planet’s estimated natural gas reserves. On top of these are tundra methane deposits estimated at 1500 billion tonnes. Together these two immense sources of carbon could boot global temperatures up by 5-10 degrees if they melt as a result of man-made warming of the Arctic and shallow seas around the continents.

What happens next is somewhat speculative, because it depends on incalculable factors in the Earth’s system – and in the human character. The issue is whether such large increases in global temperatures in turn trigger further irreversible feedbacks, releasing yet more greenhouse gases, in an episode known as runaway global warming. For example, the oceans begin to evaporate more rapidly and water vapour, being another greenhouse gas, accelerates warming.

The current scientific worst case scenario here is an increase in global temperatures of about 16 degrees, which would render much of the planet uninhabitable by humans and eliminate agricultural food production. Such a scenario might not spell extinction however – Siberia, the Canadian north and Antarctica might remain habitable for survivors using advanced technologies to produce food.

To view the absolute downside, you only have to go outside on a clear evening and look west. That bright star is Venus, where it is 465 degrees in the shade; the Venusian atmosphere is mostly CO₂ and 90 times heavier than ours. Being similar in mineral composition to Earth, Venus probably once had water and maybe oceans; faint traces remain in its atmosphere, the last vestiges of a catastrophic planetary warming episode. The message to Earthlings from the Evening Star is plain: this is what can happen to a planet if you release all your carbon and boil off your oceans.

However our own behaviour is liable to be a far more immediate determinant of human survival or extinction. Above two degrees – which we have already locked in – the world’s food harvest is going to become increasingly unreliable, as the Intergovernmental Panel on Climate Change warned this week. That means mid-century famines in places like India, China, the Middle East and Africa. But what scientists cannot predict is how humans living in the tropics and subtropics will respond to this form of stress. So let us turn to the strategic and military think tanks, who like to explore such scenarios, instead.

The Age of Consequences study by the US Centre for Strategic and International Studies says that under a 2.6 degree rise “nations around the world will be overwhelmed by the scale of change and pernicious challenges, such as pandemic disease. The internal cohesion of nations will be under great stress…as a result of a dramatic rise in migration and changes in agricultural patterns and water availability. The flooding of coastal communities around the world… has the potential to challenge regional and even national identities. Armed conflict between nations over resources… is likely and nuclear war is possible. The social consequences range from increased religious fervour to outright chaos.” Of five degrees – which the world is on course for by 2100 if present carbon emissions continue – it simply says the consequences are "inconceivable".

Eighteen nations currently have nuclear weapons technology or access to it, raising the stakes on nuclear conflict to the highest level since the end of the Cold War. At the same time, with more than 4 billion people living in the world’s most vulnerable regions, scope for refugee tsunamis and pandemic disease is also large. It is on the basis of scenarios such as these that scientists like Peter Schellnhuber – science advisor to German President Angela Merkel – and Canadian author Gwynne Dyer have warned of the potential loss of most of the human population in the conflicts, famines and pandemics spinning out of climate impacts. Whether that adds up to extinction or not rather depends on how many of the world’s 20,000 nukes are let off in the process. These issues all involve assumptions about human, national and religious behaviour and are thus beyond the remit of scientific bodies like the IPCC, which can only hint at what they truly think will happen. So you are not getting the full picture from them.

However in a classic case of improvident human behaviour, a global energy stampede is taking place as oil, gas, coal, tar sands and other miners (who, being technical folk, understand quite clearly what they are doing to the planet) rush to release as much carbon as possible as profitably as possible before society takes the inevitable decision to ban it altogether. Thanks to them, humanity isn’t sleep-walking to disaster so much as racing headlong to embrace it. Do the rest of us have the foresight, and the guts, to stop them? Our ultimate survival will be predicated entirely on our behaviour – not only on how well we adapt to unavoidable change, but also how quickly we apply the brakes.

Which form of human behaviour prevails will probably settle the extinction argument, one way or the other. It’s our call.

Global Warming Could Be Accelerated by Microbes

Global Warming Could Be Accelerated by Microbes
Chester Davis, April 8, 2014 guardianlv.com

The frozen ground just below the Earth’s surface might hold a hidden danger for the planet’s climate. Permafrost teems with microbes that could be able to accelerate global warming under the right conditions.

Scientists have long known that several mechanisms can contribute to global warming, including carbon dioxide emissions from engines and power plants. The melting of the permafrost in northern latitudes is another source of so-called greenhouse gases. What wasn’t so clear before was the mechanism that released carbon dioxide and methane from the frozen tundra.

Researchers at Florida State University conducted a study of how the permafrost works, and found a simple mechanism involving bacteria, that could contribute in a substantial way to climate change.

What happens depends on organic material being available. Availability depends on whether the soil remains frozen or not. In the Arctic, that permafrost is thawing, making more organic material available to those microbes.

Environmental scientist Jeff Canton, of Florida State University, described the process. Frozen soil starts to thaw. The layer of soil collapses into what used to permafrost and becomes saturated with water. Organic matter in the water is now available to be broken down by anaerobic (able to grow in the absence of oxygen) bacteria to produce carbon dioxide and methane, which can lead to global warming.

Using a sample of Arctic permafrost, the international research team studied soil composition, focusing on what would change the ratio of methane to carbon dioxide produced by bacteria present below the surface.

The amount of carbon dioxide is greater, at first, than the amount of methane. Over time, the organic matter changes in composition, in a way that increases methane production much more than carbon dioxide production. Production of both gases increases, but the ratio changes from 10:1 to 1:1, said Dr. Chanton.

The latest study is part of a world-wide collaborative effort involving scientists from Australia, Europe, and North America. The methane in the soil gets released as new plant species, sphagnum moss then sedges start to grow. Methane is 33 times more powerful a greenhouse gas than is carbon dioxide. As the world gets warmer, additional methane would just add to the problem.

Suzanne Hodgkins, doctoral student at Florida State University and lead author of the study, said that we have known about the thawing permafrost. The new study shows that changes in plants growing in the far north could lead to far more greenhouse gases being released into the atmosphere.

The paper was published in Proceedings of the National Academy of Sciences.

Permafrost covers approximately 24 percent of the exposed land in the northern hemisphere, with most being in Siberia, northern Canada, and Alaska. Some alpine permafrost exists further south in the mountains.

Another study on the connection between greenhouse gases and the landscape indicated that deserts could trap more carbon dioxide than previously thought. That study was published April 6 in the online science journal Nature Climate Change.

Now that scientists know how changes in tundra permafrost can release greenhouse gases, the challenge remains to actually do something about it. Knowing that global warming could be accelerated by microbes under the tundra adds another mechanism of climate change to cope with.

Arctic Death Spiral and the Methane Time Bomb

Arctic Death Spiral and the Methane Time Bomb
Published on Nov 18, 2013

Many thanks to:
Peter Sinclair - Greenman Studios
David Suzuki - David Suzuki Foundation
Dr. Guy McPherson - Professor Emeritus University of Arizona
Pauline Schneider - Filmmaker
Dr. Richard Somerville - Scripps Institution of Oceanography (wrong credit given in film)
Severn Cullis-Suzuki - Activist
Thom Hartmann - "The Man"
Dr. Natalia Shakhova - International Arctic Research Center
Nick Breeze - Filmmaker
Dr. James Hansen - NASA (Ret.)
Dr. Alun Hubbard - Aberystwyth University
Dr. Marco Tedesco - NOAA
James Balog - Filmmaker "Chasing Ice"
Dr. Peter Wadhams - University of Cambridge
David Wasdell - Apollo-Gaia Project
Omar Cabrera - Methanetracker.org
Lester R. Brown - Earth Policy Institute
Dr. Richard Milne - University of Edinburgh
Dan Miller - A REALLY Inconvenient Truth
Dr. Charles Miller - NASA JPL
Dr. Kevin Schaefer - USNSIDC
Dr. Jason Box - GEUS
Ben Abbott - University of Alasaka
John Tyndall - Tyndall Centre
Uli Hamacher - Filmmaker
Dr. Igor Semiletov - International Arctic Research Center
Dr. Richard Alley - Penn State University
and all the other whom made this film possible...

Methane-producing microbes may be responsible for the largest mass extinction in Earth's history

Methanosarcina barkeri fusaro. Credit: public domain

Methane-producing microbes may be responsible for the largest mass extinction in Earth's history

Mar 31, 2014 phys.org

Evidence left at the crime scene is abundant and global: Fossil remains show that sometime around 252 million years ago, about 90 percent of all species on Earth were suddenly wiped out—by far the largest of this planet's five known mass extinctions. But pinpointing the culprit has been difficult, and controversial.

Now, a team of MIT researchers may have found enough evidence to convict the guilty parties—but you'll need a microscope to see the killers.

The perpetrators, this new work suggests, were not asteroids, volcanoes, or raging coal fires, all of which have been implicated previously. Rather, they were a form of microbes—specifically, methane-producing archaea called Methanosarcina—that suddenly bloomed explosively in the oceans, spewing prodigious amounts of methane into the atmosphere and dramatically changing the climate and the chemistry of the oceans.

Volcanoes are not entirely off the hook, according to this new scenario; they have simply been demoted to accessories to the crime. The reason for the sudden, explosive growth of the microbes, new evidence shows, may have been their novel ability to use a rich source of organic carbon, aided by a sudden influx of a nutrient required for their growth: the element nickel, emitted by massive volcanism at just that time.

The new solution to this mystery is published this week in the Proceedings of the National Academy of Sciences by MIT professor of geophysics Daniel Rothman, postdoc Gregory Fournier, and five other researchers at MIT and in China.

The researchers' case builds upon three independent sets of evidence. First, geochemical evidence shows an exponential (or even faster) increase of carbon dioxide in the oceans at the time of the so-called end-Permian extinction. Second, genetic evidence shows a change in Methanosarcina at that time, allowing it to become a major producer of methane from an accumulation of carbon dioxide in the water. Finally, sediments show a sudden increase in the amount of nickel deposited at exactly this time.

The carbon deposits show that something caused a significant uptick in the amount of carbon-containing gases—carbon dioxide or methane—produced at the time of the mass extinction. Some researchers have suggested that these gases might have been spewed out by the volcanic eruptions that produced the Siberian traps, a vast formation of volcanic rock produced by the most extensive eruptions in Earth's geological record. But calculations by the MIT team showed that these eruptions were not nearly sufficient to account for the carbon seen in the sediments. Even more significantly, the observed changes in the amount of carbon over time don't fit the volcanic model.

"A rapid initial injection of carbon dioxide from a volcano would be followed by a gradual decrease," Fournier says. "Instead, we see the opposite: a rapid, continuing increase."

"That suggests a microbial expansion," he adds: The growth of microbial populations is among the few phenomena capable of increasing carbon production exponentially, or even faster.

But if living organisms belched out all that methane, what organisms were they, and why did they choose to do so at that time?

That's where genomic analysis can help: It turns out that Methanosarcina had acquired a particularly fast means of making methane, through gene transfer from another microbe—and the team's detailed mapping of the organism's history now shows that this transfer happened at about the time of the end-Permian extinction. (Previous studies had only placed this event sometime in the last 400 million years.) Given the right conditions, this genetic acquisition set the stage for the microbe to undergo a dramatic growth spurt, rapidly consuming a vast reserve of organic carbon in the ocean sediments.

But there is one final piece to the puzzle: Those organisms wouldn't have been able to proliferate so prodigiously if they didn't have enough of the right mineral nutrients to support them. For this particular microbe, the limiting nutrient is nickel—which, new analysis of sediments in China showed, increased dramatically following the Siberian eruptions (which were already known to have produced some of the world's largest deposits of nickel). That provided the fuel for Methanosarcina's explosive growth.

The resulting outburst of methane produced effects similar to those predicted by current models of global climate change: a sudden, extreme rise in temperatures, combined with acidification of the oceans. In the case of the end-Permian extinction, virtually all shell-forming marine organisms were wiped out—consistent with the observation that such shells cannot form in acidic waters.

"A lot of this rests on the carbon isotope analysis," Rothman says, which is exceptionally strong and clear in this part of the geological record. "If it wasn't such an unusual signal, it would be harder to eliminate other possibilities."

While no single line of evidence can prove exactly what happened in this ancient die-off, says Rothman, who is also director of MIT's Lorenz Center, "the cumulative impact of all these things is much more powerful than any one individually." While it doesn't conclusively prove that the microbes did it, it does rule out some alternative theories, and makes a strong and consistent case, he says.