The Great Climate Leap (2018)

The Great Climate Leap

William H. Calvin[1]

Global effort on the climate problem, from community organizations to the highest UN levels, has focused for a half-century on reducing emissions from burning fossil fuels. But things have changed because of extreme weather. An analysis shows that, as logical as it sounds, emissions reduction will not work in time. This prompts us to rethink our assumptions about climate change and our future: additional strategies are now needed.

About ten years ago, three types of extreme weather leaped on stage, as if a threshold had been crossed. They arrived with no warning and show no signs of going away. Given the possibility of additional sustained surges, an effective climate intervention must now be quick—very quick, such as a major carbon dioxide (CO2) cleanup in the next twenty years.

Twenty years ago, I wrote a cover story for The Atlantic on climate instability, “The great climate flip-flop,” and have continued to attend to the frontiers of climate science, writing a university-press book along the way, Global Fever. Now, emerging science is offering a new narrative that focuses on changes in extreme weather; it sounds warning bells calling us to urgent action. To explain, I will first address climate leaps and critique current climate actions, then discuss the kinds of fast interventions we could use against extreme weather.

Five Climate Leaps

We became accustomed to thinking that serious climate change was far off and would arrive gradually, proportional to the buildup of greenhouse gases. Yet, while CO2 continued to creep up, climate change suddenly began to bite hard about ten years ago. This was not a mere doubling; there are now three aspects of extreme weather that can, in retrospect, be recognized as having taken large steps up.

Deluge: Those three-day downpours. After 2009, the annual number of billion-dollar-plus floods in the U.S., not counting those from hurricanes, surged to four times as many. It was a step: the numbers have not come back down, nor have insurance premiums.

Severe storms: This annual count of billion-dollar-plus windstorms in the U.S. includes tornados and derechos (a very wide line of thunderstorms sweeping forward together at freeway speeds), though not hurricanes. After 2005, the number of severe storms tripled; after 2010, there were seven times as many as in the average baseline year (Fig. 1). This annual rate is also remaining high. Seven-times-higher, plus sustained, suggests that a new climate mechanism has been engaged, such as the hairpin turns now frequently seen in the more sluggish polar jet stream.

Mega heat waves: The planet was hit by two heat waves (Western Europe in 2003, Russia in 2010) that each killed a hundred times more people than “huge” heat waves of the 20th century. There were no intermediate stops at five or ten times as huge, just straight to a hundred times as huge. Hence, mega.

An epidemic of extreme weather struck and is continuing. Though other types of extreme weather are worsening as well, droughts, fires, winter storms, and tropical cyclones (hurricanes) did not surge to the same extent. The three types of extreme weather that leaped are all likely related to blocks and exotic weather intrusions from jet stream abnormalities, which are follow-on effects of the rapid Arctic warming that began in 1993 (Fig. 2).

So, it seems that we have gone from creeps to leaps—big leaps: triple, four-fold, seven-fold, hundred-fold. It has taken a decade’s perspective to realize we were hit by a game-changer back then, not just by bad patches of random weather, gone tomorrow. We had no warning of such a big step-up in climate deterioration—no idea that extreme weather could have a sustained surge. Had some climate scientists dared to predict such a thing, their reputations would have suffered. Now we know: surges that stick are possible and could happen again. “Thinking gradual” is now an inadequate guide to the future.

The game-changer

As a medical school professor, I’m familiar with a physician having to tell a patient that, despite all her prevention measures, she now has a serious, potentially fatal disease. The new treatment is usually quite different from the precautionary measures; doubling down on the precautions will no longer work. Of the options available to the patient, “wait and see” may be the worst. That is where we are with climate. The new extreme weather is a game-changer and calls for an additional type of treatment, a bolder intervention.

The new extreme weather events could trip up the global economy, especially when just-in-time food supplies are interrupted and lead to food riots. That 2010 mega heat wave, only seven years after the first one, also ruined 30 percent of Russia’s grain crop—so they stopped exporting. That created widespread political instability; the soaring price of bread triggered the food riots that synchronized the 2011 Arab Spring uprisings. What if a mega happened much more often? Across North America as well as Eurasia?

A further step-up in the rates of extreme weather could pose a near-term threat—at the high end, its potential impact ranks somewhere between a global economic collapse and a human population crash. To call it a human extinction threat would be an exaggeration, but the chain reaction from hits to agriculture, to the economy, and to security does qualify as a threat to civilization. We need to focus on getting through the next twenty years in a way that avoids the slippery slope that collapsed several dozen societies in the past, which Jared Diamond described in his book, Collapse.

“Wait and see” is now our worst option, sure to make things more difficult, not only for our children but ourselves. Note, however, that our ancestors survived many threats; our situation is hardly hopeless. This is a major challenge like fighting a great war—another “Do it or else” that demands our best thinking and collaborative action.

A critique of emissions reduction

Tremendous effort and innovation have been fueled by our commitment to reduce emissions of fossil fuels. Renewable energy is now less expensive, in many cases, than fossil fuels. Green jobs are a growth industry, and the focus on emissions reduction has deepened public awareness of the climate crisis. The Paris Climate Agreement reflects near-global agreement about the importance of climate action, with incentives for improvement.

But such improvements are very slow to register with climate mechanisms; they cannot do the more immediate job of reducing extreme weather. We should continue such efforts because they will improve life, both now and in mid-century after the big cleanup I will describe. But emissions reductions will not influence the extreme weather that surged ten years ago—and could take another leap.

Saying “climate solution” implies a fix: a repair or restoration or bracing. Most “climate solutions” are, unfortunately, none of these. They do not push back, only hinder slightly. While, in service of galvanizing public action, we say “Every little bit counts,” there is a danger this strategy will make us think we are doing something effective, when in fact our efforts will fail to limit extreme weather in our lifetimes. Only carbon dioxide removal can reverse overheating and acidification; only big-enough government action can walk back the extreme weather.

Almost everything we have done has been a sensible prevention measure that is analogous to dieting or brushing one’s teeth. It is now time to evaluate our half-century-long strategy.

First: has emissions reduction worked for its intended purpose? If so, we would expect the annual bump-up in atmospheric CO2 to be declining. Atmospheric CO2 increased 0.7 parts per million (ppm) each year back in the early 1960s; in 2015 and 2016, it climbed 3.0 ppm each year. A three-fold increase is the wrong kind of progress. In the focus on emissions reductions achieved in industrialized countries, we sometimes forget that many developing countries are burning their local fossil fuels because of their increased need for air-conditioning and refrigerating food. Can they be expected to zero their emissions anytime soon? No.

Second, it is important to realize that the logic of reducing emissions contains a fallacy, one we can no longer ignore. We say, correctly, that fossil fuel emissions are the cause of our climate troubles. So, get rid of them! Zero emissions! This is excellent reasoning, provided that nature will do the cleanup job on the time scale of days to weeks, the way it does with smog and other forms of air pollution. Surveys show that 93 percent think that, when we get around to achieving zero emissions, the excess will go away as fast as they think air pollution does. Rain often works wonders, but not for greenhouse gases. Only 7 percent of people realize it takes a century or more for nature to do a CO2 cleanup.

Nature removes most methane (the active ingredient of natural gas) on a time scale of a decade or two. But for CO2, nature’s cleanup is agonizingly slow. To be rid of just 80 percent of today’s excess CO2—probably enough to bring us back to a safe level—will take a thousand years of zero emissions. Our excess CO2 is what is causing our present extreme weather and will continue to do so until removed, even if we achieve zero emissions tomorrow.

Third, we could sweep the CO2 drawdown problem under the rug for as long as the accumulation level remained “safe.” In retrospect, that time probably ended a quarter-century ago when the Arctic warming began its steep rise (Fig. 2). Back in 1993, the CO2 was at 357 ppm. Now, at 408 ppm, the CO2 level is already at least 51 ppm above “safe” and represents an excess of 128 ppm (that’s 46 percent) above the old pre-industrial level of 280 ppm, which was also the Ice Age maximum concentration (180 ppm was the low). We are in uncharted territory, and we now know that big leaps are possible.

CO2 accumulation levels must be brought down if we are to whiten the Arctic summers again, allowing snow and ice to reflect incoming sunlight back out into space again and cool the planet. This is not a situation that a CO2 diet can fix, not for many centuries.

Even without the new goad from extreme weather, it would be time to try something in addition to emissions reduction, something quicker. Delaying a CO2 drawdown is now the “path of most harm.”

Making the paradigm shift

Climate change is a lot to wrap our hearts, heads, and strategic policy around—a complex jigsaw puzzle, each piece of which is a downer. Physicians may get used to this, but most Ph.D. scientists have little experience in dealing with disaster scenarios. Had the scope been less overwhelming, more thought-leaders might have recognized twenty years ago that we should intervene with our own cleanup, if only because nature’s method acidifies the ocean’s surface waters and reduces the plankton production that generates half the oxygen we breathe. The plankton also serve as the bottom of the ocean’s food chain. If we intervene successfully in the next twenty years, we stand a better chance of keeping the global environment much as we presently know it.

Now we have a much more urgent reason to clean up the excess CO2: backing out of the epidemic of extreme weather. Imagine growing seasons becoming so unpredictable that a second crop rarely succeeds—and even the main crop is often stunted. When agricultural productivity drops dramatically because of a mega heat wave, and other places are in trouble at the same time, a just-in-time country cannot import food from elsewhere. In the past, such crop failures (usually from drought) often triggered famine, civil disorder, resource wars, and genocides.

Brushing one’s teeth helps prevent tooth decay, but having a toothache is a game-changer. Then, one needs the abscess drained and painted with antibiotics, the tooth decay removed, and so forth. That’s now our situation with climate: prevention has failed, so we need a cleanup as well as continuing our prevention measures.

Making the paradigm shift will be cognitively challenging; it will be tempting to stay focused on the now-outdated carbon diet paradigm—in part because we have made progress, and because feeling as though one has some positive influence over one’s future is essential for mental health. But the world has changed: the slide into resource wars, with associated human, ecological, and cultural costs is one we must become committed to surmounting at all costs. Most environmental leaders do not yet understand the severity of our situation, rarely mentioning on their websites the need to remove CO2 from the air. However, alerting and educating our current politicians is of the utmost importance; we cannot wait for some of them to lose elections. They currently control the purse-strings for the needed large-scale cleanup.

To be blunt, we must act before we become trapped. A speedy intervention is not just desirable, but essential. There has been little discussion of how much time we have left until we are trapped on a slippery slope with more deterioration ahead, no matter how hard we try. Given business as usual, my own estimate for when we achieve ‘doomed’ is mid-century. But I could be wrong.

The Solution Space

Emissions reduction is now necessary but not sufficient. How can we push back climate change more effectively, not merely hinder its advance? Prevention aspects aside, what are our possible interventions?

We could reflect more sunlight back out into space, probably by mimicking the volcanic aerosols in the stratosphere that cool things for several years. Such Solar Radiation Management (SRM) proposals may sound effective, but it is their possible effects on weather’s seasonal time scale that cause their unpopularity, much as in the old debates on cloud seeding (inducing rain in one region may take it away from another region downwind). SRM sounds risky, and it is. But, of course, so is the situation we are now in.

While I think creating clouds and aerosols may have some limited regional applications for heatwaves (preserving Arctic ice, generating off-shore fog before winds carry the air into coastal cities), I doubt SRM will provide any years-long solution to our global overheating problem, in particular because their uneven application will cause new problems via rearranging winds and rains. And, of course, they do not address the ocean acidification aspect of excess CO2. SRMs are only a temporary measure, rather like putting plastic sheeting over a broken skylight to keep out the rain.

How, then, do we quickly capture the excess CO2 in the air? The rest of the solution space is known as Carbon Dioxide Removal (CDR), which some call Negative Emissions Technologies (NETs); doubling our forests is the only current example of a big-enough solution. CDR proposals address both overheating and acidification, but few are going to meet the criteria of doing the job that now needs doing: drawing down the excess CO2 in the air in a way that is quick enough to keep the economic, legal, and security arrangements on which we depend from being battered apart in coming decades by even more extreme weather. For example, CDR via new forests is not quick enough; forests take fifty years to reach maturity. Biochar may enrich soils but, besides being energy-intensive and competing for water and agricultural land as does reforestation, it is neither big nor quick.

CDRs must also be sure-fire and, once built, secure from disruption; new forests can easily burn down, putting CO2 right back in the air for fifty years. A giant dry-ice plant was recently proposed, though power for running the process in a world already needing much more air-conditioning is another impediment, as is storing that CO2 ice. My present opinion is that we must cache the excess CO2 from CDR either in depleted oil and gas wells or dissolved in the ocean depths—the depths already hold far larger amounts of dissolved organic carbon and CO2 than the cleanup would add.

Yes, ocean depth-cached CO2 will eventually upwell, starting about a thousand years from now, and thus end up in the air—a common objection raised, but it is not valid. A closer look at ocean upwelling data suggests that most CO2 from the depths will trickle out slowly, between 1,000 and 6,000 years from now, time enough for the slow CDR methods such as reforestation and biochar to address the problem.

The timelines in a recently published review of CDR proposals suggest that even the more promising will take 200 years to do the essential CO2 drawdown, ten times too slow to stop the new agricultural deterioration from extreme weather. We must find new ways to take the excess CO2 out of circulation before economy, environment, and security further fall apart and we become unable to act effectively.

Sinking the CO2 (literally)

Many CDR proposals rely on photosynthesis to capture the CO2 in the usual green way. Actually, leaves are not required. With the help of breaking waves, the CO2 in the air mixes into the surface layer of the ocean where tiny plankton also do photosynthesis, creating organic carbon molecules such as sugar that allow them to grow. About half of their dry weight is carbon taken from atmospheric CO2. Bacteria and plankton can double their numbers in a single day. Leaves do not double their numbers in a day—nothing on land can match such increases in ocean primary production rates.

How can one safely, and with the fewest side-effects, sink more CO2 into the ocean depths? The particle-sized debris that is heavy enough to sink below the wind-mixed surface layer of the ocean (about 50 meters thick over the Continental Shelf, more than 100 meters farther out) takes its carbon out of atmospheric circulation. The approach so far has been to enhance the rain of debris via surface fertilization.

Unfortunately, a fertilization-only method would require a tripling of the entire ocean’s productivity to do the big-and-quick drawdown of the excess CO2. This would produce massive side effects and is now a discredited approach. We can cross off fertilization-only from the list, but fertilization is still very useful in the context of nearby down-pumps, about which there has been little discussion so far in the CDR literature.

Organic debris that is small enough to stay suspended in the surface layer gets eaten by bacteria within weeks, producing CO2 that then makes it back into the nearby atmosphere. That is the fate of 77 percent of what the plankton photosynthesis earlier took out of dissolved CO2 from the air. That suspended debris, and some of the plankton, is what we need to take out of circulation, even more than the 23 percent that settles out by itself. Down pumps could target the 77 percent that doesn’t settle out—plus any excess amounts of the living plankton.

Elsewhere I have discussed pumping surface waters down to supplement the natural downwellings produced by the 30 km-wide whirlpools found at high latitudes near Greenland and Antarctica. They carry organic carbon down into thousand-year storage in the ocean depths, both as living plankton plus the hundred-fold greater amounts of dissolved organic carbon from debris. Once we add pumping arrays that mimic this natural process, we sink far more potential CO2 (Fig. 3, “carbon soup”) than the settling of larger debris into the depths. Should we fertilize to sink even more?

Plankton numbers keep increasing until one of the ingredients is exhausted, just as a factory production line stops when a single part is no longer available. Sometimes the missing ingredient is iron but phosphate shortages are common as well. The most likely place to find a supply is in the debris of dead organisms which accumulates just below the wind-mixed surface layer, about 30 to 50 meters down. They are upwelled when steady winds push surface water aside, achieving “fertilization,” but they can also be pumped up by a windmill.

The combination of down pumps to 200 meters and up pumps from 50 meters is a potent combination; it can sink a lot of atmospheric CO2. Fertilization to enhance down-pumping is an entirely different matter than fertilization-only. While pumping up to fertilize also brings along some undesired CO2 to the surface (the second reason usually offered for dismissing ocean pumps), the nearby down pump makes up for that by sinking much larger amounts of potential CO2. Such plankton wind farms might require one percent of the ocean surface, probably far offshore along the edge of the Continental Shelf.

This proposed plankton wind farm is meant to provide a concrete example, easy to visualize (thus, windmills to sink surface waters rather than the likely-superior wave-driven pumps) and simplified to make it easy to remember. It serves to define the response ballpark by checking all of the right boxes for any CO2 drawdown proposal: big (can sink 500 GtC), quick (in 20 years), and relatively invulnerable to the expected extreme weather and resource wars of the coming decades. It is a solution that does not compete for the land and fresh water needed for food production, nor does it compete for the electricity needed for air-conditioning. Its push-pull pumps are independent and sufficiently spread out in space so that there is no critical piece to capture and hold hostage.

Mine is an intentionally simplified model, meant to illustrate to the public and legislators an important part of the solution space; it is not something that one starts deploying next year. It and a half-dozen other CO2 removal proposals need significant work by real experts, the sort of multidisciplinary effort we saw in the space race of the 1960s. Those projects that meet the big-quick-surefire criteria ought to be urgently pursued in parallel through field trials such that we can transition to mass manufacture and deployment within five years, aiming to achieve a large drawdown by 2040.

It is important to note that CDR must first counter the ongoing emissions from all countries, currently about 10 GtC annually (the carbon in 37 Gt of CO2). It is only with enough pumping to annually sink 11 GtC that atmospheric CO2 will begin to decline, making relief possible. In the model, that’s at least ten years from now as we ramp up to removing 40 GtC each year by 2030. Unfortunately, a lot can happen before then—and even more if we keep delaying action. We need to heed the admonition sometimes attributed to British statesman Edmund Burke: “The public interest requires doing today those things that men of intelligence and goodwill would wish, five or ten years hence, had been done.”

We need decisive government-level action, and we are now short on time. For example, we cannot wait for international cost-sharing to be negotiated. We in the United States can start the cleanup with wartime priorities and set a good example for others to follow. The military is trained to think ahead and already treats climate troubles as a serious threat. The Pentagon’s Defense Advanced Research Projects Agency may be the best positioned to oversee the project; DARPA funded the development of the internet, one of America’s gifts to the world. DARPA would likely assemble a design team of scientists, engineers, and architects at a suitable location, keeping them there full-time for several years until prototypes were working well and field trials began.

This is the time to reach out to elected officials and demand effective action, with funding to address the climate emergency as an existential threat. We now have the same type of emergency as when a dam starts to crack, when managers immediately draw down the reservoir that threatens to wipe out towns downstream. For climate leaps, that includes human habitations all around the globe. We must draw down CO2 from its accumulation overhead. It is now appropriate to treat this as an emergency, analogous to preparing for a great war looming on the horizon.

There is nothing hopeless about our situation. Like war, it is risky—but properly focused actions can greatly improve our chances. The trip to Hell is not a sure thing.

—end, about 4000 words—

Recommended reading for editors, with links

D. Archer, Fate of fossil fuel CO2 in geologic time. J. Geophys. Res. 110, C09S05, doi: 10.1029/2004JC002625 (2005).

Beal, C. M., Archibald, I., Huntley, M. E., Greene, C. H., & Johnson, Z. I., Integrating Algae with Bioenergy Carbon Capture and Storage (ABECCS) Increases Sustainability, Earth’s Future, 6, (2018).

Calvin WH, The great climate flip-flop. The Atlantic 281(1):47-64 (1998)

Calvin WH, Global Fever: How to Treat Climate Change. London and Chicago: University of Chicago Press. (2008)

Calvin WH, Emergency 20-year drawdown of excess CO₂ via push-pull ocean pumps. MIT ClimateCoLab Proposal for Geoengineering (Finalist). (2013).

Calvin WH, Extreme Weather: The Game-Changer (Policy Matters), submitted. (2018a)

J. Diamond (2005), Collapse: How Societies Choose to Succeed or Fail. New York: Viking,

Jennifer A. Francis, Why Are Arctic Linkages to Extreme Weather Still up in the Air? BAMS, (2018).

Francis, J. A., and S. J. Vavrus, Evidence linking Arctic amplification to extreme weather in mid-latitudes. Geophys. Res. Lett., 39, L06801, (2012).

Francis, J., & Skific, N. (2015). Evidence linking rapid Arctic warming to mid-latitude weather patterns. Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences, 373(2045), 20140170.

Marco Lagi, Karla Z. Bertrand and Yaneer Bar-Yam (2011) The Food Crises and Political Instability in North Africa and the Middle East. Tech. Rep., New England Complex Systems Institute,

Jan C Minx, et al (2018) Negative emissions—Part 1: Research landscape and synthesis. Environmental Research Letters 13(6) 063001,

G. F. Nemet, M. W. Callaghan, F. Creutzig, S. Fuss, J. Hartmann, J. Hilaire, W. F. Lamb, J. C. Minx, S. Rogers, P. Smith, Negative emissions—Part 3: Innovation and upscaling. Environ. Res. Lett. 13, 063003, doi: 10.1088/1748-9326/aabff4 (2018).

Robine J.-M., et al. (2008), Death toll exceeded 70,000 in Europe during the summer of 2003. C. R. Biologies 331,

Will Steffen, et al (2018) Trajectories of the Earth System in the Anthropocene. Proceedings of the National Academy of Sciences Aug 2018, 201810141;

Strand S, Benford G (2009) Ocean sequestration of crop residue carbon: recycling fossil fuel carbon back to deep sediments. Environ Sci & Tech 43:1000-1007.

Trenberth, K. E. & Fasullo, J., Climate extremes and climate change: The Russian heat wave and other climate extremes of 2010. J. Geophys. Res. 117, D17103.

Trouet, V., Babst, F. & Meko, M., Recent enhanced high-summer North Atlantic Jet variability emerges from three-century context. Nature Communications 9, 180, (2018).

von Hippel, T., Thermal removal of carbon dioxide from the atmosphere: energy requirements and scaling issues. Climatic Change 148: 491. (2018). [dry ice plant, also excellent review]

Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K. Maycock (eds.). Climate Science Special Report: Fourth National Climate Assessment, Volume I. U.S. Global Change Research Program, Washington, DC, USA, (2017).

[1] William H. Calvin, Ph.D., is a professor emeritus at the University of Washington’s School of Medicine in Seattle. He is the author of sixteen books, translated into seventeen languages. Particularly relevant is Global Fever (University of Chicago Press, 2008). He wrote The Atlantic ’s cover story on climate instability, “The Great Climate Flip-Flop,” in January 1998. He received the 2002 Phi Beta Kappa award for science as literature. Email: