PNAS: Trajectories of the Earth System in the Anthropocene

[David Klein]

Proceedings of the National Academy of Sciences

Trajectories of the Earth System in the Anthropocene


Will Steffen, Johan Rockström, Katherine Richardson, Timothy M. Lenton, Carl Folke, Diana Liverman, Colin P. Summerhayes, Anthony D. Barnosky, Sarah E. Cornell, Michel Crucifix, Jonathan F. Donges, Ingo Fetzer, Steven J. Lade, Marten Scheffer, Ricarda Winkelmann, and Hans Joachim Schellnhuber
PNAS August 6, 2018. 201810141; published ahead of print August 6, 2018. Trajectories of the Earth System in the Anthropocene


Abstract
We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a “Hothouse Earth” pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene. We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies. Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System—biosphere, climate, and societies—and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values.

_________________________

The Anthropocene is a proposed new geological epoch (1) based on the observation that human impacts on essential planetary processes have become so profound (2) that they have driven the Earth out of the Holocene epoch in which agriculture, sedentary communities, and eventually, socially and technologically complex human societies developed. The formalization of the Anthropocene as a new geological epoch is being considered by the stratigraphic community (3), but regardless of the outcome of that process, it is becoming apparent that Anthropocene conditions transgress Holocene conditions in several respects (2). The knowledge that human activity now rivals geological forces in influencing the trajectory of the Earth System has important implications for both Earth System science and societal decision making. While recognizing that different societies around the world have contributed differently and unequally to pressures on the Earth System and will have varied capabilities to alter future trajectories (4), the sum total of human impacts on the system needs to be taken into account for analyzing future trajectories of the Earth System.

Here, we explore potential future trajectories of the Earth System by addressing the following questions.

• Is there a planetary threshold in the trajectory of the Earth System that, if crossed, could prevent stabilization in a range of intermediate temperature rises?
• Given our understanding of geophysical and biosphere feedbacks intrinsic to the Earth System, where might such a threshold be?
• If a threshold is crossed, what are the implications, especially for the wellbeing of human societies?
• What human actions could create a pathway that would steer the Earth System away from the potential threshold and toward the maintenance of interglacial-like conditions?

 

[Brad H]

Trajectories of the Earth System in the Anthropocene

There is virtually no "social science" evident in this paper, aside from comments that recognize non-radical solutions that haven't worked: "Incremental linear changes to the present socioeconomic system are not enough to stabilize the Earth System"

From a physical science perspective, here is what they say is required for a "Stabilized Earth":

"Stabilized Earth would require deep cuts in greenhouse gas emissions, protection and enhancement of biosphere carbon sinks, efforts to remove CO2 from the atmosphere, possibly solar radiation management, and adaptation to unavoidable impacts of the warming already occurring (48)."​

The best they can come up with (is a pitiful) is for humanity, us, to "play an active planetary stewardship role", pointing to UNSDG goals - a continuing dumbing-down of serious vision. The report is basically a condensed overview of positive and negative feedbacks and the recognition of apprehension of "abrupt" rather than "linear" climate change. Virtually nothing new or surprising in the list.

What is most aggravating is the persistent usage of the words "could" and "might" be activated or pass threshold states, when so many papers argue several feedbacks are well into runaway - I mean - look at Arctic temps and melt and methane release and multiple amplified positive feedbacks that is putting in process and will go into even faster hyper-drive with the imminent blue ocean event... still the "brightest brains" talk about "between now and 2100", "by the end of this century" or "transition it into only a century or two".

This, my ecosocialists friends, is yet another massive example of scientific reticence, positivist myopia, instrumental rationality and affect phobia, but is what will continue to fuel the discourses of the Greenpeaces, 350.orgs, etc.

Richard, once again, I would agree that ecosocialists can't talk of a simple "just transition" when what is required is a shut down of the whole system with all that it implies in terms of massive disruptions. This requires a certain element of ruthless realism, activism, Messianism that is not evident in this kind of scienticity nor in academic Marxism.

From a scientific perspective, the biggest argument (an paradox) against that dramatic tackling of emissions, and the eerie entry of the ghost of doomism is the problem of global dimming, since a few years ago something that has been theorized by serious scientists. We need to eliminate carbon and CO2es from the atmosphere and oceans, but that also removes the particulates that keep the planet cool....

 

[David J]

For some time I had confidence that a mass act of non-violent civil disobedience ( perhaps 10,000 risking arrest at once) could jump-start the moribund "climate movement". That confidence is waning, given the new reality. Still, as a member of the newly formed DSA Ecosocialist Working Group, I will push for this tactic and stress the need for action to match urgency. The language has to reflect the severity of the crisis as well, as in, " protecting ecosystems using whatever means necessary" . The time for signing petitions, marching and chanting the same tired slogans is way, way over.

 

[Richard Smith]

The ecological footprint of work

So what, exactly, is Eric Holthaus’s suggestion for “acting boldly”? What does he (and Grist), propose that we do to stop the threat of runaway global warming? This is a good idea in the abstract. I’m all for less production and longer vacations. A couple of points:

1. Why should we assume that given capitalism working fewer hours is going to mean production of “less stuff”? I wager that replacing workers with robots will simply increase production of needless stuff instead of reducing it.

2. Instead of focusing on shortening the workweek (long a major concern of socialists), we (as ecosocialists) should be focusing on talking about industrial shutdowns — abolishing or at least retrenching the production and consumption of all kinds of useless, pointless, superfluous, destructive products and services that are cooking the planet.

Right now, for example, if you read the papers or watch the news on TV, nearly all coverage about the wildfires in California focus single-mindedly on the capitalist party line: “You should not be building houses out in the woods.” Not “you should not be producing humongous SUVs that are cooking the planet, you should not be jetting all around the world cooking the planet, you should not be building ever-bigger McMansions, you should not be buying ever-more disposable throwaway products, and so on. THAT’S what’s cooking the planet, burning up California, not building houses out in the woods. I use to hike and camp and stay at houses in the California woods in the 1960s and 70s and they weren’t burning up then. There were always a few small wildfires every summer. But now there’s no more fire season. The California fire season is 365 days a year. Building cabins in the woods is not the reason for that. Capitalist overproduction from here to China is what’s driving the burning of California.

I could not open the link in Eric's article to the Liverman doc on "possible solutions.” The Grist graphic on what you can do is explicitly focused on personal choices — “Eat a plant based diet, drive an electric car, buy green energy, avoid a round-trip transatlantic flight, have fewer children.”

Some of these are fine but they don’t grasp the depth of the Climate Emergency crisis we face which requires massive industrial shutdowns, broad de-industrialization from here to China, all of which requires the suppression of the market, total reorganization and reprioritization of our economy in favor of direct democratic planning,viz. ecosocialism. The basic problem is the built-in growth imperative in capitalism which Grist does not challenge, or perhaps see, because they have corporate support. There is just no evidence that we can shop our way to sustainability by buying green energy and electric cars so long as we live in a capitalist economy that’s dominated by the oil industrial complex and built on exponential growth. But this is a longer discussion . . .

 

[David Klein]

Trajectories of the Earth System in the Anthropocene

There is virtually no "social science" evident in this paper, aside from comments that recognize non-radical solutions that haven't worked: "Incremental linear changes to the present socioeconomic system are not enough to stabilize the Earth System"

From a physical science perspective, here is what they say is required for a "Stabilized Earth":

"Stabilized Earth would require deep cuts in greenhouse gas emissions, protection and enhancement of biosphere carbon sinks, efforts to remove CO2 from the atmosphere, possibly solar radiation management, and adaptation to unavoidable impacts of the warming already occurring (48)."​

The best they can come up with (is a pitiful) is for humanity, us, to "play an active planetary stewardship role", pointing to UNSDG goals - a continuing dumbing-down of serious vision. The report is basically a condensed overview of positive and negative feedbacks and the recognition of apprehension of "abrupt" rather than "linear" climate change. Virtually nothing new or surprising in the list.

What is most aggravating is the persistent usage of the words "could" and "might" be activated or pass threshold states, when so many papers argue several feedbacks are well into runaway - I mean - look at Arctic temps and melt and methane release and multiple amplified positive feedbacks that is putting in process and will go into even faster hyper-drive with the imminent blue ocean event... still the "brightest brains" talk about "between now and 2100", "by the end of this century" or "transition it into only a century or two".

This, my ecosocialists friends, is yet another massive example of scientific reticence, positivist myopia, instrumental rationality and affect phobia, but is what will continue to fuel the discourses of the Greenpeaces, 350.orgs, etc.

Richard, once again, I would agree that ecosocialists can't talk of a simple "just transition" when what is required is a shut down of the whole system with all that it implies in terms of massive disruptions. This requires a certain element of ruthless realism, activism, Messianism that is not evident in this kind of scienticity nor in academic Marxism.

From a scientific perspective, the biggest argument (an paradox) against that dramatic tackling of emissions, and the eerie entry of the ghost of doomism is the problem of global dimming, since a few years ago something that has been theorized by serious scientists. We need to eliminate carbon and CO2es from the atmosphere and oceans, but that also removes the particulates that keep the planet cool....

I agree with much of what Brad says, including the necessity for revolutionary changes rather than just the "reform bandaids" perfunctorily ennumerated in the article (as in so many others). But there are some observations in the article that deserve consideration, in particular this passage:

"For some feedback processes, the magnitude—and even the direction—depend on the rate of climate change. If the rate of climate change is small, the shift in biomes can track the change in temperature/moisture, and the biomes may shift gradually, potentially taking up carbon from the atmosphere as the climate warms and atmospheric CO2 concentration increases. However, if the rate of climate change is too large or too fast, a tipping point can be crossed,..."​

​

The article suggests that this factor --- the rate of warming as opposed to just the amount of warming --- along with others could determine whether the earth climate system passes through an irreversible threshold into a new hothouse climate state. Human life and the continuation of much of the biosphere would be impossible in such a climate state. Hansen has also talked about the potential importance of the rate of climate change.

So then what about reducing both the amount and the rate of global warming in order to avoid a potentially irreversible tipping point into a climate state that would end life on this planet? To date most ecosocialists oppose all forms of geoengineering (except for planet-wide afforestation and various plant and soil based solutions which unfortunately are completely inadequate to the task despite much dreamy speculation). What is required is reducing all GHG emissions to zero AND even more. To hold down the rate and amount of temperature increase, thus avoiding an irreversible tipping point into a dead planet, may very well require --- in addition to zero GHG emissions --- extraction and storage of CO2 and/or emergency solar radiation management (SRM) to immediately cool the planet. The absolute rejection of these contingencies based soley on ideology might very well be a death sentence for planet Earth.

Brad expressed aggravation over the use of the words "could" and "might" in the article. Those words were used for a reason. The whole analysis is based on qualitative considerations of climate forcings together with known bahaviors of "dynamical systems," the mathematical objects of consideralble study whose vocabulary includes terms like "stability," "basin of attraction," "limit cycles," "nonlinear dynamics," and other phrases used in the article. The conclusions do not come from any actual calculations or climate model runs, which is acknowledged in the final paragarph of the article:

"Our initial analysis here needs to be underpinned by more in- depth, quantitative Earth System analysis and modeling studies to address three critical questions..."​

​

David

 

[Brad H]

California’s Record-breaking Fire Isn’t the Week’s Worst Climate News

Thanks David for some clarifications above.

David Wallace-Wells published a response to the PNAS report yesterday. Among the summary points he makes:

- authors' recognition of dramatic increase in non-linear positive-feedback loops (PFL) means climate change more severe "than previously understood"

- we have moved beyond IPCC which "previously established boundaries of acceptable discourse"

- COP21 goal of limit of 2C will not prevent PFLs from pushing planet beyond "equilibrium" and into runaway cc, bring world quickly past 4C and beyond - basically demise of civilization

- in any case, world not on path to anywhere near even 2C, and major PFLs well underway

- PNAS push the envelope while hedging... says Wallace-Wells: "authors of the new paper do not suggest a “hothouse earth” is an inevitability — only that it is significantly more likely than most scientists would publicly acknowledge"

- (presumably this means that, privately, they are scared, and would suggest more dire scenarios)

- distinguished and conservative PNAS authors will now publicly use the word "runaway", which is a little less cautious than they have done in the past

- various upcoming credible but "more fringe" reports push the "inevitability" envelope further, but "the scientists behind the PNAS paper are probably the most distinguished yet to be raising this particular alarm"

I think the point of the PNAS article and Wallace-Wells emphasis is this:

- metaphor of cascading "dominoes" falling leaves readers with an image feeding dissonance between sober empiricism, hesitant scientific reticence and more sensuous ominous foreshadowing (literary devices that Wallace-Wells more masterfully plays with in his previous New York magazine article)

- this meant to provoke agency in ways that only positivist science can?

- PNAS writers also interestingly situate readers in an embodied now - the summer of climate disasters as a palpable warning of new normal, threat to come

- but neither Wallace-Wells nor PNAS authors then move to situate readers in a movement of radical systematic social agency, political-economic revolution, BUT

- the call for their own kind of radicalism "we need studies to show when they might cause a runaway effect"

- hmmm....

 

[Richard Smith]

THE FIRES THIS TIME

What no one wants to talk about is the inescapable imperarative need to organize a global shutdown of non-essential industries, which is now our only option. If humanity had taken serious steps to mitigate emissions decades ago in the 1980s when scientist began warning us (as the NYTimes magazine of last weekend reminds us), then perhaps we wouldn't be in the fix we're in right now. But we didn't and haven't and so now we face a CLIMATE EMERGENCY. For decades the developed economies of the world and the rogue party-state of China ignored the threat of global warming, kicked the can down the road on the assumption dangerous global warming is not imminent and not much of a threat to them, at least in the short run. After all, we in the temperate regions of the northern hemisphere have not suffered so much because (for reasons which I do not understand) the heating seems to be more extreme at the poles than the temperature latitudes. The Arctic and Antarctica are melting fast, with immediate dire implications for their inhabitants (polar bears, penguins, eskimos), but what we read about here in the U.S. is mostly about coastlines losing an half an inch or so of land, some intensified droughts here and there, more fires, even reaching into some cities (Santa Rosa) last year and so on. Life in parts of the equatorial latitudes is also becoming more precarious, thus the increase in African migration to Europe.

But the belt of furious fires all around the northern hemisphere from Greece to California to Japan, taking the lives of hundreds, have suddenly grabbed their attention. I don't know if this is the first time that the NY Times even published an article on global warming on the front page (above the fold) but I think this is the first time it has explicitly blamed global warming for the fires this time in a top-of-the-page headline.

From the first warnings of scientists, from the first efforts to come up with plans to mitigate emissions, all efforts have subordinated emissions prioritized economic growth over the environment. Whatever we do to slow global warming, it MUST NOT slow economic development. Or, as GW Bush Sr put it: "We will never sacrifice the American way of life." Thus, instead of simply imposing rationing of fossil fuels, suppressing vehicle production, grounding civilian aircraft (all of which President Rosevelt did during WWII), to the contrary mainstream efforts -- voluntary curbs (Kyoto), cap&trade, carbon taxes, the union-backed "Million Green Jobs" campaign and so on, have all been explicitly based on that priority-to-growth premise. Needless to say, they have all completely failed. So now what to do?

We can't expect any change from the powers that be. So long as we live in capitalism, all governments, all industries, all industrial unions, and most consumers will continue to support growth till we burn up all the last forests on whole west coast. The auto industry will still be flogging us their obese gas-hog Sierras and Denalis to drive off the cliff to collapse. The airlines will likely soon start marketing "lung cleansing breaks" to escape the smog (adding to the smog in the process) overseas as they do in China today.* And consumers will still be buying this line --- unless . . .

Unless we change the conversation. Unless we get people to start thinking and talking and working for a real alternative to the market-driven collapse of civilization. Our job, as ecosocialists is to put forward a practical plan to slam the brakes on emissions, an EMERGENCY RESPONSE TO THE CLIMATE EMERGENCY: This is not rocket science. The solutions are totally obvious and ready to hand. They don't require any tech fix. That plan has to begin with:

1) Public acknowledgement that we can not longer sustain an endlessly growing economy on a finite planet.
2) Public understanding that if we're going to suppress emissions, then companies, lots of companies starting with the fossil fuel producers but also auto and aircraft manufacturers, airlines, shippers, petrochemicals, food processors, disposable junk producers etc. etc. will have to be shut down or drastically retrenched. Given our desperate plight today, that's the ONLY WAY to suppress emissions.
3) Companies can't put themselves out of business voluntarily because they're owned by private shareholders. So we have to help them. We need to socialize them, nationalize them, take them into public hands so we can phase them out.
4) If we close down/retrench industries we as a society need to provide new low or no-carbon jobs for all those workers and at comparable wages and conditions. Otherwise they will not be able to see their way to joining with us to do what we have to do to save them and their children.
5) If capitalism cannot make such a massive and profound reorganization and reprioritization, then we have to transition to some kind of eco-socialism.

This is the public conversation the whole nation and the whole world needs to be having right now. There is no other alternative. Its up to us ecosocialists to motivate this conversation because no mainstream organization is willing to risk challenging the government, capitalism, unions, workers, and consumers, let alone taking them on all together. Yet the abject failure of all mainstream approaches opens the way for us to put forward more radical approaches to a bigger audience. Awful as things are at the moment, this presents a huge opportunity to ecosocialists. But we really need to get moving on this, develop SCNCC propaganda along these lines, organize forums, teach-ins, write opinion pieces, and develop ecosocialist politics within DSA.

* From Antarctica to Iceland, Chinese Seek 'Lung-Cleansing' Trips ...
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