FEBRUARY 15, 2016 9:04 AM February 15, 2016 9:04 am
Updated, 11:51 p.m. | Sustained large investments in fundamental science paid off in a big way last week, as Dennis Overbye so beautifully reported in The Times’s package on confirmation of Einstein’s 1916 conclusion that massive moving objects cause ripples in spacetime — gravitational waves.
Raymond Pierrehumbert, a climate scientist and the Halley Professor of Physics at Oxford University. Credit Eva Dalin, Stockholm University
This finding, and the patient investments and effort through which it was produced, came up in the context of humanity’s global warming challenge in an email exchange a few days ago with Raymond T. Pierrehumbert, a veteran climate scientist who was recently appointed the Halley Professor of Physics at Oxford University.*
The common context is the importance of sustained engagement on a big challenge — whether it is intellectual, as in revealing spacetime ripples, or potentially existential, as in pursuing ways to move beyond energy choices that are reshaping Earth for hundreds of generations to come.
I reached out to Pierrehumbert because he is one of many authors of “Consequences of twenty-first-century policy for multi-millennial climate and sea-level change,” an important new Nature Climate Change analysis reinforcing past work showing a very, very, very long impact (tens of millenniums) on the Earth system — climatic, coastal and otherwise — from the carbon dioxide buildup driven by the conversion, in our lifetimes, of vast amounts of fossil fuels into useful energy.
The core conclusion:
This long-term view shows that the next few decades offer a brief window of opportunity to minimize large-scale and potentially catastrophic climate change that will extend longer than the entire history of human civilization thus far. [Read the Boston College news release for even more.]**
A summary from Columbia University’s Lamont-Doherty Earth Observatory captures the basic findings:
Humans have been burning fossil fuels for only about 150 years, yet that has started a cascade of profound changes that at their current pace will still be felt 10,000 years from now.
Here’s a snippet from a figure in the paper showing how arguments about the pace of coastal change between now and 2100 distract from a profoundly clear long-term reality — that there will be no new “normal” coastal for millenniums, even with aggressive action to curb emissions:
I’d asked Pierrrehumbert to reflect on the time-scale conundrum laid out in the Nature Climate Change paper in the context of another important and provocative proposal by Princeton’s Robert Socolow, published in the Bulletin of the Atomic Scientists in December, proposing a new field of inquiry — Destiny Studies — to examine the tough intersection of ethics, risk perception and science. His essay is titled, “Climate change and Destiny Studies: Creating our near and far futures.” Here’s the abstract:
Climate change makes stringent demands on thinking about our future. We need two-sided reasoning to contend equitably with the risks of climate change and the risks of “solutions.” We need to differentiate the future 500 years from now and 50 years from now. This essay explores three pressing climate change issues, using both the 500-year and the 50-year time frames: sea level rise, the nuclear power “solution,” and fossil carbon abundance.
Here’s Pierrehumbert’s “Your Dot” contribution, tying together these elements:
The day of the release of the spectacular LIGO gravitational wave discovery is a good time to be pondering human destiny, the great things we can achieve as a species if only we don’t do ourselves in, and the responsibility to provide a home for future generations to flourish in. It is beyond awesome that we little lumps of protoplasm squinting out at the Universe from our shaky platform in the outskirts of an insignificant galaxy can, after four decades of indefatigable effort, detect and characterize a black hole merger over a billion light years away.
This is just one of the most dramatic examples of what we are capable of, given the chance to be our best selves. In science, I’d rate the revolution in detecting and characterizing exoplanets way up there as well. There’s no limit to what we can accomplish as a species.
But we have to make it through the next two hundred years first, and this will be a crucial time for humanity. This is where Destiny Studies and our paper on the Anthropocene come together. The question of why we should care about the way we set the climate of the Anthropocene is far better answered in terms of our vision for the destiny of our species than it is in terms of the broken calculus of economics and discounting.
For all we know, we may be the only sentience in the Galaxy, maybe even in the Universe. We may be the only ones able to bear witness to the beauty of our Universe, and it may be our destiny to explore the miracle of sentience down through billions of years of the future, whatever we may have turned into by that time. Even if we are not alone, it is virtually certain that every sentient species will bring its own unique and irreplaceable perspectives to creativity and the understanding of the Universe around us.
Thinking big about our destiny, think of this: the ultimate habitability catastrophe for Earth is when the Sun leaves the main sequence and turns into a Red Giant. That happens in about 4 billion years. However, long before that — in only about 500 million years — the Sun gets bright enough to trigger a runaway greenhouse effect and turn us into Venus, sterilizing all life on Earth. We waste half the main sequence lifetime of the Sun.
However, if we last long enough, technology will make it easy to block enough sunlight to save the Earth from a runaway, buying us another 4 billion years of habitability. That’s the only kind of albedo-modification geoengineering I could countenance, and by the time that is needed, presumably we’ll have the wisdom to deploy it safely and the technology to make it robust.
But we have to make it through the next 200 years first.
If we do what humanity has always done in the past, we’re likely to burn all the fossil fuels, and then have a hard landing at a time of high population, with an unbearable climate posing existential risks, at just the time when we’re facing the crisis fossil fuels running out. That will hardly make for ideal conditions under which to decarbonize, and there is a severe risk civilization will collapse, leaving our descendants with few resources to deal with the unbearable environment we will have bequeathed them.
It’s been pointed out that fossil fuels came in just about when we had run out of whale oil, but the whales had been hunted to the brink of extinction when that happened. If we do the same with coal, it’s not going to make for a pretty transition. With regard to the Anthropocene, it’s true that given a thousand years or so — if technological civilization survives — it becomes likely that we would develop ways to remover CO2 from the atmosphere and accelerate the recovery to more livable conditions. But if things get bad enough in the next two hundred years, we may never have that chance.
The alternative future is one where we decide to make the transition to a carbon-free economy before we’re forced into it by the depletion of fossil fuels. We’re going to run out anyway, and will need to learn to do without fossil fuels, so why not get weaned early, before we’ve trashed the climate? If we do that, we might not just buy ourselves a world, but a whole Universe.
Shorthand summary: Can we do better than bacteria smeared on agar?
This passage from a 2011 post, “Confronting the Anthropocene,” conveys my sense of the core focus of “destiny studies”:
We’re essentially in a race between our potency, our awareness of the expressed and potential ramifications of our actions and our growing awareness of the deeply embedded perceptual and behavioral traits that shape how we do, or don’t, address certain kinds of risks [or time scales].
Another author of the Nature Climate Change paper, Daniel Schrag of Harvard, gave a highly relevant talk at the Garrison Institute a couple of years ago in which he raised, but did not answer, a question I hope you’ll all ponder:
Is there a moral argument for some threshold of environmental conditions that we must preserve for future generations?
This would be a cornerstone question in destiny studies. I moderated a conversation on this question and the rest of the lecture with Schrag and Elke U. Weber of Columbia University. I hope you can spare some time to watch.
There are plenty of efforts to build such a field, including Oxford’s Future of Humanity Institute, the Frederick S. Pardee Center for the Study of the Longer-Range Future at Boston University and the Arizona State University effort I described in this post: “Building Visions of Humanity’s Climate Future – in Fiction and on Campus.”
Here are other relevant past pieces:
2015 – “Avoiding a Climate Inferno”
2011 – “Pedal to the Metal”
2009 – “Puberty on the Scale of a Planet”
Updated, 11:50 p.m. | David Roberts at Vox today put the Nature Climate Change paper in political context when he wrote: “The U.S. presidential election will matter for 10,000 years.” Read the rest here.
** This excerpt from the paper was added at 1:36 p.m.
*Pierrehumbert has contributed valuable insights here in the past, writes on Slate on occasion and is a fine accordion player. He contributed sensitively wrought parts on a song on my first album.