The cause is known & the solution is known

From an Article by William B. Gail, PhD, New York Times, April 22, 2019
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Donald Rumsfeld famously popularized the term “unknown unknowns” in a 2002 news briefing when describing the challenges of linking Iraq to weapons of mass destruction. Troublingly, climate change may also be strewn with such unknowns, and they pose daunting tests for how we face the future.

One is choosing among policy alternatives. Should we minimize tomorrow’s risks now by reducing greenhouse gas emissions, or save money today and spend it on adapting to the effects of planetary warming once threats emerge more fully, like rising seas or prolonged droughts? The policy debate increasingly tilts toward adaptation. But we can’t adapt to perils from unknown unknowns. In such cases, adaptation will largely fail; only mitigation will be effective.

The National Climate Assessment released last fall provided an updated scientific summary of the “knowns.” The simple version was this: Earth is warming, humans are largely responsible, ecosystems are changing in response, and the impact on societies will be large.

The report also characterized the known unknowns, as Mr. Rumsfeld might put it — those things we know at a fundamental level but about which we seek greater certainty. They include how much Earth will eventually warm, how rapidly oceans will rise, where and when weather extremes and water shortages might occur, and whether potential tipping points (like the collapse of Antarctic ice sheets) will, in fact, occur.

Unsurprisingly, the report carefully limited speculation about unknown unknowns: the many initially small environmental shifts that are potential consequences of the changing climate. What will actually emerge is largely unknowable because of the highly unpredictable nonlinear response to the warming of Earth’s complex and adaptive physical and ecological systems.

Yet credible speculation on climate’s unknown unknowns is sorely needed by policymakers. Future generations will be affected by today’s policy decisions, whether the underlying science is complete or not. The basics are simple: The more we warm our planet, the more likely it is that deeply surprising environmental changes will ensue.

Most of these smaller environmental changes should be manageable, readily addressed through adaptation. Inevitably, however, a rare few will most likely evolve and expand until they threaten our security, health or economy. We lack the ability to predict which are which. This is the curse of unknown unknowns. Nevertheless, things we can credibly imagine should accentuate our concern for what we are unable to imagine.

Perhaps a routinely ice-free Arctic summer, altering polar ocean life in subtle ways, sets off an unpredictable cascade of complex changes throughout the global ocean ecosystem, devastating fisheries. Maybe agricultural pests adapt to climate change stresses by evolving novel and frequently changing abilities to destroy crops, leaving farmers struggling to keep pace and feed populations. One unsettling risk is that mutant diseases — like Zika and Ebola today and the 1918 flu epidemic that killed 50 million people — could emerge more often because of altered evolutionary competition in a changing climate, each a greater medical challenge than the last.

Environmental changes occur regularly; climate change significantly accelerates the process. Should warming progress too far, society risks being overwhelmed by the growing rate at which disruptive events could occur. Each new threat is likely to emerge and proliferate differently, undermining adaptation’s effectiveness.

Some threats might be so startling and strange that our imaginations would struggle to comprehend them even after they arise. Timely response efforts would be frustrated by poor knowledge about what is occurring and how to contain the threat.

Though climate change has yet to produce clearly attributed examples, Zika hints at this dispiriting future. Within a few short years, it transformed from an ignorable rare disease into a medical terror. Nobody saw it coming. Its long-term societal consequences run deep, with childbearing upended for people threatened by the mosquito that carries the virus. Though probably not a direct result of climate change, Zika starkly illustrates the type of inconceivable surprises, and their demoralizing consequences, that threaten to emerge with ever greater frequency should we fail to slow global warming.

Three millenniums ago, Homer foreshadowed our dilemma. He wrote of Odysseus returning by ship across the Aegean Sea, headed homeward to Greece after his great victory over Troy. Odysseus anticipated an arduous sea journey, but was unprepared for what followed: an interminable voyage punctuated by unimaginably difficult experiences one after another, from Sirens to the Cyclops.

Our decisions in the next few years will determine whether our climate journey follows a similar course. Perhaps current policy discussions will navigate society through the journey’s recognized risks. If warming progresses rapidly, however, the known concerns — increasing temperatures, sea level rise, a melting Arctic — will not be the whole story. Nature’s unforeseeable surprises, some unimaginable to us today, could become pivotal to our fate.

Without an aggressive policy commitment to mitigation by rapidly reducing our carbon emissions, our grandchildren could be destined to live in a world with nature’s unknown unknowns around each year’s turn.

>>> William B. Gail is a co-founder of the Global Weather Corporation, a past president of the American Meteorological Society and the author of “Climate Conundrums: What the Climate Debate Reveals About Us.”

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SEE ALSO: ‘We Are Not Moving Fast Enough’: Study Shows Cost of Melting Permafrost Could Total $70 Trillion

Defending the Geo. Washington & Thomas Jefferson National Forests

“Court orders halt to Atlantic Coast Pipeline construction in national forest”

The Fourth Circuit Court of Appeals has granted a stay of the national Forest Service decisions allowing Atlantic Coast Pipeline construction.

The stay puts an immediate stop to any construction in the National Forest until an appeal filed by the Southern Environmental Law Center (SELC) and Sierra Club, on behalf of Cowpasture River Preservation Association, Highlanders for Responsible Development, Shenandoah Valley Battlefields Foundation, Shenandoah Valley Network, Sierra Club, Wild Virginia and Virginia Wilderness Committee is decided.

“This decision is very good news for the Forest. After FERC’s decision to reauthorize construction last week, Atlantic was poised to resume clearcutting its way across the two national forests today. Because of this decision, Atlantic’s chainsaws will remain idle until the Court has had an opportunity to decide our case. For the same reason, FERC should stop construction elsewhere until these issues are resolved, to avoid wasting ratepayer dollars building a route that may not be viable,” said Southern Environmental Law Center Senior Attorney, DJ Gerken.

“We’re glad to see construction of the fracked gas ACP halted in our national forests. There is no need for this dirty, dangerous pipeline and while we’re pleased with today’s decision, our air, water and communities won’t truly be protected until it’s permanently halted. The Sierra Club, our partners, and communities along the entire route will keep fighting this project until construction is finally stopped,” said Kelly Martin, Director of the Sierra Club’s Beyond Dirty Fuels Campaign.

This Friday, September 28th the Fourth Circuit Court of Appeals will hear oral argument in conservation groups’ challenge to approvals issued by the Forest Service and the State of Virginia for the Atlantic Coast Pipeline.

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See also — “Court blocks work on portion of Duke Energy-backed Atlantic Coast Pipeline to hear appeal” – Charlotte Business Journal

Earthquakes above magnitude 3 out of control (USGS)

From an Article by Emily Brodsky, The Conversation, September 2, 2018

Earthquakes in the central and eastern U.S. have increased dramatically in the last decade as a result of human activities. Enhanced oil recovery techniques, including dewatering and hydraulic fracturing, or fracking, have made accessible large quantities of oil and gas previously trapped underground, but often result in a glut of contaminated wastewater as a byproduct.

Energy companies frequently inject wastewater deep underground to avoid polluting drinking water sources. This process is responsible for a surge of earthquakes in Oklahoma and other regions.

The timing of these earthquakes makes it clear that they are linked with deep wastewater injection. But earthquake scientists like me want to anticipate how far from injection sites these quakes may occur.

In collaboration with a researcher in my group, Thomas Goebel, I examined injection wells around the world to determine how the number of earthquakes changed with the distance from injection. We found that in some cases wells could trigger earthquakes up to 10 kilometers (6 miles) away. We also found that, contradictory to conventional wisdom, injecting fluids into sedimentary rock rather than the harder underlying rock often generates larger and more distant earthquakes.

Transmitting Pressure Through Rock

Assessing how far from a well earthquakes might occur has practical consequences for regulation and management. At first glance, one might expect that the most likely place for wastewater disposal to trigger an earthquake is at the site of the injection well, but this is not necessarily true.

Since the 1970s, scientists and engineers have understood that injecting water directly into faults can jack the faults open, making it easier for them to slide in an earthquake. More recently it has become clear that water injection can also cause earthquakes in other ways.

For example, water injected underground can create pressure that deforms the surrounding rock and pushes faults toward slipping in earthquakes. This effect is called poroelasticity. Because water does not need to be injected directly into the fault to generate earthquakes via poroelasticity, it can trigger them far away from the injection well.

Deep disposal wells are typically less than a foot in diameter, so the chance of any individual well intersecting a fault that is ready to have an earthquake is quite small. But at greater distances from the well, the number of faults that are affected rises, increasing the chance of encountering a fault that can be triggered.

Of course, the pressure that a well exerts also decreases with distance. There is a trade-off between decreasing effects from the well and increasing chances of triggering a fault. As a result, it is not obvious how far earthquakes may occur from injection wells.

Where to Inject?

To assess this question, we examined sites around around the world that were well-isolated from other injection sites, so that earthquakes could clearly be associated with a specific well and project. We focused on around 20 sites that had publicly accessible, high-quality data, including accurate earthquake locations.

We found that these sites fell into two categories, depending on the injection strategy used. For context, oil and gas deposits form in basins. As layers of sediments gradually accumulate, any organic materials trapped in these layers are compressed, heated and eventually converted into fossil fuels. Energy companies may inject wastewater either into the sedimentary rocks that fill oil and gas basins, or into older, harder underlying basement rock.

At sites we examined, injecting water into sedimentary rocks generated a gradually decaying cloud of seismicity out to great distances. In contrast, injecting water into basement rock generated a compact swarm of earthquakes within a kilometer of the disposal site. The larger earthquakes produced in these cases were smaller than those produced in sedimentary rock.

This was a huge surprise. The conventional wisdom is that injecting fluids into basement rock is more dangerous than injecting into sedimentary rock because the largest faults, which potentially can make the most damaging earthquakes, are in the basement. Mitigation strategies around the world are premised on this idea, but our data showed the opposite.

How wastewater injection can make earthquakes: In basement rocks (left), injection activates faults in the small region directly connected to the added water, shown in blue. In sedimentary injection, an additional halo of squeezed rock, surrounds the pressurized fluid and can activate more distant faults.

Why would injecting fluids into sedimentary rock cause larger quakes? We believe a key factor is that at sedimentary injection sites, rocks are softer and easier to pressurize through water injection. Because this effect can extend a great distance from the wells, the chances of hitting a large fault are greater. Poroelasticity appears to be generating earthquakes in the basement even when water is injected into overlying sedimentary rocks.

In fact, most of the earthquakes that we studied occurred in the basement, even at sedimentary injection sites. Both sedimentary and basement injection activate the deep, more dangerous faults – and sedimentary sequences activate more of them.

Although it is theoretically possible that water could be transported to the basement through fractures, this would have to happen very fast to explain the rapid observed rise in earthquake rates at the observed distances from injection wells. Poroelasticity appears to be a more likely process.

Avoiding Human-Induced Quakes

Our findings suggest that injection into sedimentary rocks is more dangerous than injecting water into basement rock, but this conclusion needs to be taken with a rather large grain of salt. If a well is placed at random on Earth’s surface, the fact that sedimentary injection can affect large areas will increase the likelihood of a big earthquake.

However, wells are seldom placed at random. In order to efficiently dispose of wastewater, wells must be in permeable rock where the water can flow away from the well. Basement rocks are generally low permeability and therefore are not very efficient areas in which to dispose of wastewater.

One of the few ways that basement rocks can have high permeability is when there are faults that fracture the rock. But, of course, if these high permeability faults are used for injection, the chances of having an earthquake skyrocket. Ideally, injection into basement rock should be planned to avoid known larger faults.

If a well does inject directly into a basement fault, an anomalously large earthquake can occur. The magnitude 5.4 Pohang earthquake in South Korea in 2017 occurred near a geothermal energy site where hydraulic injection had recently been carried out.

The important insight of this study is that injection into sedimentary rocks activates more of these basement rocks than even direct injection. Sedimentary rock injection is not a safer alternative to basement injection.