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I find some hope for the future of our planet in the emergence of millions of unconnected environmental and social movements. The leaderless Anarchy of this mass phenomenon and its macro scale means that its cells will not be centrally controlled or turned aside by profit motives. It seems to be a genuine grass roots response to the global threat which our planet faces. —Paul Hawken «

Breaching a “carbon threshold” could lead to mass extinction

What Does Climate Change Really Mean to California’s Water Resources?

August 6, 2019 Robert Shibatani Guest blogger

By Robert Shibatani

Whether you are a water utility manager, elected official, or homeowner, future water availability is a concern. There are several factors fostering that concern and one of them is climate change. In fact, these days, climate change is a rapidly growing global hot topic (no pun intended). But as the empirical evidence mounts and a once doubtful citizenry become more informed, it is instructive to review what a changing climate fundamentally means to California’s water resources; arguably our most important.

There have been many reports, commissioned studies, Statewide Plans, visionary and mission statements over the years, each providing an enlightening overview of the climate change state-of-knowledge at the time and what the most recent evidence was indicating. Outstanding efforts have been made by several State authorities to bring this information to the public. Most of our State leaders now acknowledge climate change as a clear and present danger. Their commitment, often in the face of less than fully supportive administrations in D.C, is highly commendable. However, there is much left to do, but California is one of the leading U.S. States in the dissemination of climate change information.

Today, we can say that there is agreement on some basic expectations for future water resources in the State as a result of continuing climatic change. But what does that really mean? How will it directly affect California’s waterbodies and waterways? How will it affect all of the water utilities, irrigation districts, water conservation and flood control districts across the State? And how will it affect each of us, the consumer, beneficial user, and resident of our daily necessities and activities?

The primary question is somewhat misleading since one cannot realistically decouple water resources from all of the other natural resources, processes and managed activities that make up our livelihoods. All of our social, cultural, financial, and recreational pursuits. To give the question fair tribute, a thorough multi-disciplinary review of all the secondary and tertiary direct and indirect effects would be necessary. But we’ll leave that to another time. For the purposes of this narrative, let us confine ourselves to strict water resource-related activities.

Water resources across the State can be broadly grouped into two primary categories. First, the inherent or ambient resource itself; which would include all of the waterbodies, waterways, and conventional storage. Second, the managed portion of the annual cycled resource; this includes what we do with all of the snow, meltwater, and rain we receive each year, how and for what purposes. These two categories represent the majority of the State’s static water resource reserves at any given time.

Conclusions from many early studies on California’s water resources have not materially changed. We have to remember that the early projections, despite seeming precision, were based on spatial and physical limitations (relative to today) and at rudimentary spatial scales that did not offer the majority of field water managers the resolution needed to establish definitive conclusions about future climatic projections; certainly not sufficient enough to develop specific management prescriptions.

For California, there are several broadly accepted projections. For example, everyone accepts ongoing and accelerating snowpack depletion. That means a reduced spring freshet until, at some point, the complete elimination of “melt-enhanced” spring flows as annual hydrographs for California reservoir inflows become direct rainfall-runoff generated. On the one hand this becomes easier to project and simulate since the inflow is a direct function of tributary inflow, on the other hand, it requires more judicious winter-spring operations as carryover must be more carefully managed; the spring refill can’t be continually relied upon.

Changing hydroclimatic character across broad swaths of the State will lead to net wetter and drier areas. The inflection point between wetter and drier as systems from the interior Pacific move inland is still a crude projection; likely lying somewhere between Santa Barbara and the Bay Area. Along with net changes in annual precipitation, the intensity and frequency of measurable events will also pose considerable threats to the State’s infrastructure, commerce, and resident livelihoods.

Major rivers and their higher order tributaries will see altered flow regimes. Some will be drastic, others more muted. A real concern to all water users of these waterways and waterbodies is the regulatory and institutional approvals that have been granted by regulatory agencies; approvals that were based on an analysis of the hydrology of the past and now bear increasingly little similarity to what we can expect in the future. This growing incompatibility will extend from water rights, to water quality permits, to water transfers, to power purchase agreements, to flood control operations, etc. Somewhat surprisingly, particularly for California, is the fact that virtually no effort has been undertaken to assess the potential extent, depth, and implications of these incompatibilities. Regulatorily, we are blindly stumbling ahead with climate change in terms of water resources adaptation.

Over the next 30+ years, we will see notable changes in riverine hydrology across the State. Some extreme year sequencing will generate elevated concerns, but nothing that can’t be endured in the short-term.

The real concern is that the water industry is focusing on the wrong issues, having been influenced by the GHG curtailment lobby. A zero-carbon footprint (assuming such a lofty goal is even possible), while laudable, is not going to materially affect a utility or State from major water resource problems. Source control of GHGs must be a federal commitment, not something placed on State- and regionally-based industries. China, India and other SE Asian industry giants must be wooed by D.C., not Sacramento. A utility’s responsibility is to its ratepayers and customers today, tomorrow and next month. Adaptive measures must be developed now, focusing on local/regional delivery and service obligations to ensure continued service.

The State needs a real policy wake-up on climate change … the physical environment is changing and our entire regulatory framework is unprepared …

About the Author:  Robert Shibatani, a physical hydrologist with over 35-years combined academic, legal, consulting and water advisory expertise, is an international expert witness on reservoir-operations, climate change hydrology, commercial flood damage litigation, and water supply development.  He is Managing Partner for The SHIBATANI GROUP International, a division of The SHIBATANI GROUP Inc. and resides in Sacramento, California. robert@theshibatanigroup.com

Carbon dioxide emissions may trigger a reflex in the carbon cycle, with devastating consequences, study finds.

Jennifer Chu | MIT News Office 
July 8, 2019

In the brain, when neurons fire off electrical signals to their neighbors, this happens through an “all-or-none” response. The signal only happens once conditions in the cell breach a certain threshold.

Now an MIT researcher has observed a similar phenomenon in a completely different system: Earth’s carbon cycle.

Daniel Rothman, professor of geophysics and co-director of the Lorenz Center in MIT’s Department of Earth, Atmospheric and Planetary Sciences, has found that when the rate at which carbon dioxide enters the oceans pushes past a certain threshold — whether as the result of a sudden burst or a slow, steady influx — the Earth may respond with a runaway cascade of chemical feedbacks, leading to extreme ocean acidification that dramatically amplifies the effects of the original trigger.

This global reflex causes huge changes in the amount of carbon contained in the Earth’s oceans, and geologists can see evidence of these changes in layers of sediments preserved over hundreds of millions of years.

Rothman looked through these geologic records and observed that over the last 540 million years, the ocean’s store of carbon changed abruptly, then recovered, dozens of times in a fashion similar to the abrupt nature of a neuron spike. This “excitation” of the carbon cycle occurred most dramatically near the time of four of the five great mass extinctions in Earth’s history.

Scientists have attributed various triggers to these events, and they have assumed that the changes in ocean carbon that followed were proportional to the initial trigger — for instance, the smaller the trigger, the smaller the environmental fallout.

But Rothman says that’s not the case. It didn’t matter what initially caused the events; for roughly half the disruptions in his database, once they were set in motion, the rate at which carbon increased was essentially the same.  Their characteristic rate is likely a property of the carbon cycle itself — not the triggers, because different triggers would operate at different rates.

What does this all have to do with our modern-day climate? Today’s oceans are absorbing carbon about an order of magnitude faster than the worst case in the geologic record — the end-Permian extinction. But humans have only been pumping carbon dioxide into the atmosphere for hundreds of years, versus the tens of thousands of years or more that it took for volcanic eruptions or other disturbances to trigger the great environmental disruptions of the past. Might the modern increase of carbon be too brief to excite a major disruption?

According to Rothman, today we are “at the precipice of excitation,” and if it occurs, the resulting spike — as evidenced through ocean acidification, species die-offs, and more — is likely to be similar to past global catastrophes.

“Once we’re over the threshold, how we got there may not matter,” says Rothman, who is publishing his results this week in the Proceedings of the National Academy of Sciences. “Once you get over it, you’re dealing with how the Earth works, and it goes on its own ride.”

A carbon feedback

In 2017, Rothman made a dire prediction: By the end of this century, the planet is likely to reach a critical threshold, based on the rapid rate at which humans are adding carbon dioxide to the atmosphere. When we cross that threshold, we are likely to set in motion a freight train of consequences, potentially culminating in the Earth’s sixth mass extinction.

Rothman has since sought to better understand this prediction, and more generally, the way in which the carbon cycle responds once it’s pushed past a critical threshold. In the new paper, he has developed a simple mathematical model to represent the carbon cycle in the Earth’s upper ocean and how it might behave when this threshold is crossed.

Scientists know that when carbon dioxide from the atmosphere dissolves in seawater, it not only makes the oceans more acidic, but it also decreases the concentration of carbonate ions. When the carbonate ion concentration falls below a threshold, shells made of calcium carbonate dissolve. Organisms that make them fare poorly in such harsh conditions.

Shells, in addition to protecting marine life, provide a “ballast effect,” weighing organisms down and enabling them to sink to the ocean floor along with detrital organic carbon, effectively removing carbon dioxide from the upper ocean. But in a world of increasing carbon dioxide, fewer calcifying organisms should mean less carbon dioxide is removed.

“It’s a positive feedback,” Rothman says. “More carbon dioxide leads to more carbon dioxide. The question from a mathematical point of view is, is such a feedback enough to render the system unstable?”

An inexorable rise

Rothman captured this positive feedback in his new model, which comprises two differential equations that describe interactions between the various chemical constituents in the upper ocean. He then observed how the model responded as he pumped additional carbon dioxide into the system, at different rates and amounts.

He found that no matter the rate at which he added carbon dioxide to an already stable system, the carbon cycle in the upper ocean remained stable. In response to modest perturbations, the carbon cycle would go temporarily out of whack and experience a brief period of mild ocean acidification, but it would always return to its original state rather than oscillating into a new equilibrium.

When he introduced carbon dioxide at greater rates, he found that once the levels crossed a critical threshold, the carbon cycle reacted with a cascade of positive feedbacks that magnified the original trigger, causing the entire system to spike, in the form of severe ocean acidification. The system did, eventually, return to equilibrium, after tens of thousands of years in today’s oceans — an indication that, despite a violent reaction, the carbon cycle will resume its steady state.

This pattern matches the geological record, Rothman found. The characteristic rate exhibited by half his database results from excitations above, but near, the threshold. Environmental disruptions associated with mass extinction are outliers — they represent excitations well beyond the threshold. At least three of those cases may be related to sustained massive volcanism.

“When you go past a threshold, you get a free kick from the system responding by itself,” Rothman explains. “The system is on an inexorable rise. This is what excitability is, and how a neuron works too.”

Although carbon is entering the oceans today at an unprecedented rate, it is doing so over a geologically brief time. Rothman’s model predicts that the two effects cancel: Faster rates bring us closer to the threshold, but shorter durations move us away. Insofar as the threshold is concerned, the modern world is in roughly the same place it was during longer periods of massive volcanism. 

In other words, if today’s human-induced emissions cross the threshold and continue beyond it, as Rothman predicts they soon will, the consequences may be just as severe as what the Earth experienced during its previous mass extinctions.

“It’s difficult to know how things will end up given what’s happening today,” Rothman says. “But we’re probably close to a critical threshold. Any spike would reach its maximum after about 10,000 years. Hopefully that would give us time to find a solution.”

“We already know that our CO2-emitting actions will have consequences for many millennia,” says Timothy Lenton, professor of climate change and earth systems science at the University of Exeter. “This study suggests those consequences could be much more dramatic than previously expected. If we push the Earth system too far, then it takes over and determines its own response — past that point there will be little we can do about it.”

This research was supported, in part, by NASA and the National Science Foundation.