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Climate Change is an Energy Problem. Here’s How We Solve It.

For the California Magazine article, click here.  

Count on comedians to nail the zeitgeist.

I’m thinking of comics like Marc Maron, whose act riffs off existential pain points like mortality, antisemitism, the delaminating geopolitical situation, and, of course, that multigigaton carbon elephant in the room, climate change. “The reason we’re not more upset about the world ending environmentally, I think, is that, you know, all of us in our hearts really know that we did everything we could,” Maron deadpans. “We brought our own bags to the supermarket,” he says, then pauses a few beats. “Yeah, that’s about it.” No surprise that comedians are able to play our eco-dread for yuks. Comedy is often rooted in the fertile manure of uncomfortable truths: we laugh so we don’t sob. And that’s all fine and good; laughter’s a good antidote to the malaise that comes from doomscrolling our newsfeeds day in, day out. But are we really ready to throw in the towel and laugh ourselves into oblivion? And is Maron correct? Have we really done nothing to confront our foremost environmental crisis? Hardly. True, we haven’t yet reversed the upward trend in greenhouse gas emissions, and the challenge of transitioning away from fossil fuels often seems insurmountable. Is it, though? According to Berkeley experts interviewed for this story, there’s reason for hope that we’ll make it through the bottleneck yet. The technology is already here and improving all the time. It won’t be easy, but it is doable. Now, let’s see how:


a statue of a man holding up a disco ball
If you’re looking for a peg to hang your hopes on, start with energy economics and, in particular, the price of solar panels. Costs have dropped by nearly 90 percent since 2009, driven by both improved technology and global production (particularly from China). In 1976, solar electricity cost $106 a watt; today, it costs less than 50 cents per watt. Bottom line: Solar is now competitive with fossil fuels as a means of energy production. While solar still only accounts for 3.4 percent of domestic energy consumption, production has been growing by more than 20 percent annually over the past five years, and likely would have been higher if not for shipping and supply chain difficulties stemming from the pandemic. Production isn’t everything, however. For widespread adoption, an energy source must be available on demand. And it’s here that fossil fuels have a big leg up. Natural gas or coal can be burned at any time to generate electricity as required. Solar panels produce only when the sun shines. Storing adequate energy for later use—i.e., at night or on cloudy days—has long posed a major obstacle.
Solar production has been growing by more than 20 percent annually over the past five years, and likely would have been greater but for the pandemic.
Not anymore, says Daniel Kammen, the founding director of Cal’s Renewable and Appropriate Energy Laboratory and a professor in the Energy and Resources Group and the Goldman School of Public Policy. A coordinating lead author of the Intergovernmental Panel on Climate Change since 1999, he shared in the 2007 Nobel Peace Prize. “I don’t see storage as a major problem at this point,” Kammen says. “It’s not a single breakthrough that makes me think that way, but more that we’re seeing the same trend in price and performance for storage that we saw with photovoltaics. A variety of approaches are coming to market, and they’re scaling really fast. Things that used to take several years to develop now take a year, and that’s almost certain to continue.” The storage of the future will serve two different sectors, observes Kammen: transportation (think electric vehicles) and everything else (homes, office buildings, factories, etc.).


a plug cord making the shape of a car
From a climate change point of view, an electrified vehicle fleet is desirable because it dovetails nicely with a green electric grid—i.e., one fed by sustainable energy sources. Currently, cars burning gasoline or diesel spew about 3 gigatons of carbon into the atmosphere each year—about 7 percent of total human-created CO² emissions. Just electrifying roughly a third of China’s vehicle fleet could slash carbon emissions by a gigaton a year by 2040. So there’s a lot at stake with electric vehicles, and everything considered, Kammen is pretty sanguine about their progress. “It’s really been picking up, particularly over the last year,” he says. “It’s probably not a coincidence that gasoline and diesel prices have been spiking at the same time, and I hate to think that the war in Ukraine is part of that, but it probably is.” EVs are now the best-selling cars in California, Kammen continues, “and it’s the same in Norway, and it’ll soon be the same in New York. Prices on EVs are coming down. The trend is strong and accelerating.” EVs generally store energy in batteries that use lithium, a relatively rare element that charges and discharges rapidly and is lightweight—an essential quality for automobiles, where excess weight is anathema. Lithium battery technology is well advanced, and some EVs can now go 400 miles between charging, alleviating earlier anxieties about limited range.
A central goal of the Biden administration is the construction of 500,000 new EV charging stations. For perspective: There are currently fewer than 150,000 gas stations in the entire United States.
The next challenge to overcome is a paucity of charging stations, a reality that still gives Tesla drivers pause before embarking on a long road trip. But that’s being remedied, Kammen says, thanks in significant part to the 2022 Inflation Reduction Act (see sidebar), which provides generous home and business tax credits for new and used EV purchases and fast-charging EV stations. A central goal of the Biden administration is the construction of 500,000 new EV charging stations distributed across all 50 states and the District of Columbia and Puerto Rico by 2030. For a little perspective on how ambitious that number is, consider: There are currently fewer than 150,000 gas stations in the entire United States. “Worries over charging station access are real, there’s no denying it,” says Kammen. “But this legislation, coupled with the fact that recharge times are now very fast, will make a huge difference. The one thing that we still have to address, though, is the social justice component,” as not all zip codes will see the same resources. Without policies to ensure otherwise, Santa Monica will likely have charging stations aplenty; South Central Los Angeles not so much. “We really need to ensure that doesn’t happen,” says Kammen. “First, it’s wrong. Second, to make a real difference, both energy production and transport must progress across a broad scale. That’s an easier case to make when everyone benefits.”


batteries behind a city skyline
In addition to transportation, urban infrastructure must transition to sustainable, carbon-free energy as well. That will require combining clean energy with adequate storage to provide “grid reliability”—that is, systems that will keep the juice flowing in all seasons, even when the sun is absent or the wind stops blowing. In short, you need really, really big batteries. But what kind of batteries? Lithium-ion batteries, already well established, are one option, says Kammen. But the qualities that make them ideal for vehicles—lightweight, fast charging capabilities—aren’t as critical when you’re trying to light a city at night. For stationary power needs, batteries can be industrial scale—heavy, with a large footprint. Another problem with lithium is its scarcity. The United States currently controls less than 4 percent of global reserves. For that reason alone, researchers are looking for alternatives: batteries that employ cheaper and more readily available elements. One of the most promising approaches, according to several sources, is iron-air batteries. And one of the leaders in the technology is Form Energy, a company headquartered in Massachusetts with satellite facilities in Berkeley. Zac Judkins ’06 is the company’s vice president of engineering. He stresses that Form was obsessed with finding a way to address the problem of multiday storage, not enamored of a particular technology.
Judkins and colleagues evaluated a wide array of candidate chemistries before settling on iron-air batteries, which work by rusting and unrusting thousands of iron pellets with every cycle.
“When we started up in 2017, we saw that the world was rapidly moving to renewables—mainly solar and wind—and setting increasingly ambitious grid reliability and decarbonization goals.” Without effective storage, however, progress was going to hit a brick wall, Judkins says. Analyzing the market, Form’s engineers arrived at a target. They needed to build a battery that could continuously discharge for 100 hours at a total cost of $20 per kilowatt-hour and had a round-trip efficiency (the amount of energy stored in a battery that can later be used) of 50 percent. Those parameters, Judkins says, would allow for very high adoption of renewables with no sacrifice to grid reliability and minimal increase in cost to consumers. “That was the benchmark we had to hit.” Judkins and colleagues evaluated a wide array of candidate chemistries before settling on iron-air batteries, which work by rusting and unrusting thousands of iron pellets with every cycle. Says Judkins, “We didn’t invent the iron-air battery. It was developed by Westinghouse and NASA in the late ’60s and ’70s. They’re not good for cars—they’re not light, and they don’t discharge rapidly. But there are advantages. For one thing, iron is abundant. It’s cheap. We don’t have to worry about supply constraints.” What you also get with iron, says Judkins, is low cost and high energy density—i.e., the amount of juice you can put into the battery. The tradeoff is lower power density—how fast you can pull the energy out relative to volume. “It’s roughly 10 times lower on power density than lithium-ion, but for our needs it’s fine,” says Judkins. “This is storage for large-scale, grid-tied projects.” Take the example of a large photovoltaic array like those on California’s Carrizo Plain. One array there has a 250-megawatt capacity, enough for about 100,000 homes, but only when the sun is shining. At night, during storms, there’s no electricity. But, says Judkins, with the addition of a Form plant with a footprint of 100 acres or so, you could store enough energy to keep the electricity flowing for a four-day period. The company is now transitioning from proof of concept to full production. Ironically, the first commercial rust/unrust battery systems will likely come out of the Rust Belt. “We’re building a factory in West Virginia on a 55-acre site—a former steel plant—that will have approximately 800,000 square feet of production space and employ 750 people at full operation.” Green jobs. Once the plant is fully on its feet, Judkins says, it will produce 50 gigawatt-hours of storage capacity every year.


In sub-Saharan Africa alone, 600 million people live without electricity. Providing them carbon-free power will require microgrids.
Large, centralized utility grids are naturally the focus for decarbonizing developed countries—but they don’t really apply to parts of the world where access to electricity is still rare. In sub-Saharan Africa alone, 600 million people live without electricity, which doesn’t mean they don’t want it. Providing carbon-free power to these communities will require microgrids: small systems that serve neighborhoods, hamlets, or even multiple villages. But while the microgrid concept has been kicking around for years, its full realization has been elusive—until recently. “What we’re seeing is a meshing of enabling technologies,” says Duncan Callaway, an associate professor of Energy and Resources at Berkeley and a faculty scientist at Lawrence Berkeley National Laboratory. For starters, he points to cheap solar. “With the profound price drop in panels, it’s a truly affordable resource that’s ideally suited for mid-latitude countries,” which experience less seasonality. “In general, you can serve electric demand with solar better in those latitudes than in countries [closer to either pole], where there’s just less sunlight.” Another driver is cheaper, better storage options, Callaway says. For microgrid-scale, lithium-ion batteries work well. And these, too, have grown more affordable. “The explosive growth in electric vehicles really pushed things along,” Callaway says. “Ten years ago, it cost $1,000 for one kilowatt-hour of storage. Now it costs less than $100.” Finally, says Callaway, “smart grid” technologies have been developed that make microgrids, once notoriously balky, highly efficient. “We now have ‘big bucket’ control systems that allow for the smooth coordination of energy production, storage, and demand,” Callaway says. “That makes these small grids both low-cost and really reliable. The goal is to make systems that are truly modular, so you can plug various components into larger systems. That will allow easy customization and scaling.” More than 150 microgrids already are deployed in the United States, powering everything from individual buildings in large cities to small, remote villages in Alaska. As far as widespread adoption goes, Callaway doesn’t foresee many technical difficulties. It’s social and political roadblocks that need to be overcome. “The great thing about microgrids is that they work well in remote, underserved areas and they can be managed locally. But in less developed countries, there are often corrupt governments that want their cut from any project. And if that’s the case, you’d have an inherent bias toward centralized grids with baseline power plants.” It’s a challenge that must be met, says Callaway. “Somehow, some way, small grid technology must be put on a level playing field with the old system, the large, centralized grid—or it’s unlikely to make it, even where it’s clearly the superior choice.”


Glowing electric light bulb isolated
Microgrid or macrogrid, we’ll need a lot of clean, sustainable energy flowing through the wires if we’re going to simultaneously sustain an advanced civilization and cool the planet. Kammen is convinced it will largely come from fusion. But by that he means fusion in all its forms, including, as noted, the sun: that massive reactor in the sky that continually fuses hydrogen into heavier elements, releasing 3.8 x 10²6 joules of energy every second. But there’s also that will-o’-the-wisp that’s been tantalizing futurists and physicists for decades: terrestrial fusion reactors. These would use hydrogen—the most common element in the universe—as feedstock to generate gigawatt-hours of cheap energy, producing harmless, inert helium as the primary by-product. (Radioactive tritium would also be generated, but it has a short half-life and it’s consumed by the reactor in a closed-loop process.) Fusion technology remains the Holy Grail of clean, Earth-friendly energy production, but it’s also the butt of waggish comments. The most common is that it looks promising, but it’s 20 years away. And it’s been 20 years away for 60 years. But after a breakthrough on December 5, 2022, at Lawrence Livermore National Laboratory’s National Ignition Facility (NIF), it now seems highly possible that a commercial fusion reactor actually could be available in, uh, well, 20 years. Maybe sooner. Most fusion efforts to date have involved tokamak reactors—toroidal vacuum chambers that corral hydrogen atoms via magnetic coils, subjecting them to heat and pressure until they become plasma, a superheated (as in 150 million degrees Celsius) gas that allows the hydrogen to fuse. This releases energy that transfers as heat to the chamber walls, where it is harvested to produce steam to drive turbines for electricity production.
For the first time on this planet—other than during a thermonuclear explosion—a fusion reaction was created that produced more energy than was required to initiate the process.
Tokamaks have been able to coax hydrogen to fuse for brief periods—indeed, progress has been steady, if plodding, since the first machine was built 60 years ago. But to date, they haven’t been able to achieve “ignition”—that point at which sustained fusion occurs, and more energy is produced by the device than it consumes. NIF took a different approach. Researchers there fabricated a minute pellet from frozen deuterium and tritium (both hydrogen isotopes). They then placed the pellet in a small gold capsule known as a hohlraum, which in turn was situated on an arm in a chamber bristling with 192 lasers. The scientists then fired the lasers simultaneously at the hohlraum, causing the inner capsule to compress. The result: temperatures and pressures exerted on the deuterium/tritium admixture were extreme enough to produce ignition. For the first time on this planet—other than during a thermonuclear explosion—a fusion reaction was created that produced more energy than was required to initiate the process. True, the sustained yield was modest. The reaction lasted less than a billionth of a second and released 3.15 megajoules of energy, or slightly less than one kilowatt-hour. Not very much, in other words; the average American household uses about 900 times that every month. Still, it was 50 percent more energy than was expended by the laser bursts. Progress! But here’s another catch: While the actual laser beams represented only around two megajoules of energy, it took about 300 megajoules to power up and operate the mechanisms that fired the beams. So, there’s still a lot to be done before we’re microwaving our frozen burritos with fusion power. Nevertheless, Kammen, ever the optimist, is fairly sure we will be soon. “Given the trends, I think I’m pretty safe in predicting that we’ll derive about 70 percent of our power from fusion by 2070,” Kammen says. “Half of that will be from the sun and half from fusion power plants.” And while NIF’s laser-blasted pellet approach points to future success, don’t rule out tokamaks. Kammen says he’s “expecting some exciting announcements about tokamak reactors pretty soon.” You heard it here first. Solar fusion, too, will follow multiple avenues toward fuller implementation. “It’s not just rooftop panels in cities and solar farms out on the landscape,” he says. “There’ll also be marine solar—large arrays out in the ocean.” Also: orbital solar. Live trials are now underway at Caltech and the Jet Propulsion Laboratory, says Kammen, to establish large, autonomously assembled (i.e., no live astronauts required) solar arrays in space. The energy would be beamed down as microwaves to terrestrial collectors, where it would be converted to electricity. That may raise the specter of a loose-cannon death ray immolating cities from orbit if something goes awry—but not to worry, says Kammen. “The watt-per-square-meter dose is pretty low, so there’s no danger of anyone getting fried if they’re hit by it.” He also thinks the fusion technology now under development for terrestrial reactors will have applications for space travel. “There’s a dual angle on fusion that’s really catapulting the technology,” Kammen says. “For better or worse, it’s imperative that we colonize the solar system so our fate as a species isn’t completely tied to one planet. Fusion propulsion will be an excellent means for getting us to the moon and Mars and beyond, and fusion—solar, reactor, or both—will also serve as a base-load power source when we get there.”


Fission generates a lot of energy from a small footprint. Diablo Canyon, California’s sole nuclear plant, produces almost 10 percent of the total electricity consumed in the state, and it does it within a confine of 600 acres.
With all the fuss over fusion, the other “nuclear” power source, fission, seems to have faded into the background. That’s illusory. Fission is still quite hot, so to speak, with increasing numbers of erstwhile foes in the environmental community now embracing it—or, at least, tacitly supporting it. The reasons are clear. First, fission can generate a great amount of energy on a small footprint. Diablo Canyon, California’s sole operating commercial fission plant, produces almost 10 percent of the electricity consumed in the state and does it within a confine of 600 acres. And from a climate change perspective, nukes are peerless: they emit zero CO². Of course, people remain worried about other kinds of emissions, such as intense radioactivity from long-lived waste isotopes. And older generation plants—that is, most of the ones operating today—are susceptible to core damage to varying degrees, with catastrophic results à la Chernobyl and Fukushima. Those concerns are entrenched, especially in the United States, where environmental issues, regulatory red tape, and simple cost often conspire to scotch large infrastructure projects in the proposal phase. “We’re pretty bad at megaprojects in this country,” says Rachel Slaybaugh, formerly an associate professor in nuclear engineering at Berkeley and now a partner at venture capital firm DCVC. “For one thing, it’s incredibly easy for them to go over budget. Just look at the new Bay Bridge, which ran triple the original estimates.” That problem is compounded for nuclear plants, given heightened safety concerns and the regulations and litigation they engender. But there has been an upside to the impediments imposed on traditional nuclear power, Slaybaugh says: Out of necessity, more efficient—and perhaps more socially acceptable—technology has been developed. The newer reactors are smaller—some much smaller—than the behemoths of yore, and pilot projects are underway. “A good many of these designs originated from basic concepts developed in the 1950s or 1960s, but their refinement and commercial deployment is being driven in large part by our inability to construct large projects,” Slaybaugh says. Different reactors have been designed for different situations, Slaybaugh observes, employing various fuels, coolants, and configurations. Some “breeder” reactors could even burn their own byproducts, greatly reducing radioactive waste. “What’s the priority?” Slaybaugh asks rhetorically. “Economics? Providing high-temperature heat, or balancing renewables on the grid? Minimizing nuclear waste? A combination of different goals? These new designs can be standardized or customized and scaled for the site and requirements, and all involve considerable engineering to ensure safety.” Some of the reactors will be large enough to power a city, or several cities. “And others will be teeny,” Slaybaugh says. “Those will be perfect for remote military bases or research facilities, say Antarctica or the Arctic. You’d eliminate several major problems with one of these very small reactors. Think of the logistical difficulties involved in getting diesel fuel to an arctic base, not to mention the heavy pollution it produces and, of course, the CO² that’s emitted.” Fission technology also has some profound advantages over renewables, she says. “There are real limits to how many solar farms and wind turbines we should or even can build,” she observes. “A lot of materials are required for their production, and a lot of mining is needed to get the necessary elements. And these facilities tend to have very large footprints. I’m actually worried that we’re going to see a strong solar and wind backlash as people really start to understand all the impacts.” Every energy source has strengths and weaknesses, continues Slaybaugh, “and we need to have sophisticated conversations on what they are and where each can best apply. Ultimately, my view of fission is that it’s a necessary tool that we must use in conjunction with other available tools to get the job done as well and as quickly as possible. No single solution is going to work for all scenarios.”


At this point, we know what we must do to turn things around. Even better, we have the technologies and techniques to do it. But we need to deploy them.
Reducing carbon emissions is not the complete solution to global warming, say scientists. To really get a handle on the problem, we’ll also need to remove existing CO² from the atmosphere and sequester it permanently in the ground. One option, direct air capture (DAC), is the basis for a small but growing industry: Currently, there are about 20 DAC pilot plants operating, in total capturing and sequestering around .01 megaton of atmospheric CO² annually. According to the International Energy Agency, that storage could grow to 60 megatons a year by 2030, assuming large-scale demonstration plants proceed apace, current techniques are refined, and costs drop as the technology scales. But those are a lot of assumptions for minimal benefit. Granted, a 60-megaton mass of anything is impressive. But from a climate-change perspective, 60 Mt is negligible, given energy-related carbon emissions hit an all-time high of over 36.8 billion tons in 2022. Many researchers think there are better options, and we don’t have to do anything to develop them because they already exist. They point to natural carbon sinks: forests, wetlands, grasslands, and, most significantly, the oceans. These natural systems are part of the Earth’s carbon cycle, which absorbs and releases about 100 gigatons of carbon a year. A planetary mechanism of that scale might seem more than adequate to handle carbon emissions, and it would, if atmospheric CO² only originated from natural emission points such as volcanoes and hydrothermal vents. As noted recently by MIT professor of geophysics Daniel Rothman, natural sources contribute ten times more carbon to the atmosphere than human activities, but it’s the anthropogenic carbon that is pushing the cycle over the edge. The planet can’t process the extra atmospheric carbon back into a stable earthbound state fast enough. This deficit is exacerbated by the fact that we’re degrading our carbon sinks even as we’re pumping more CO2 into the sky. “The ecological services carbon sinks provide are really priceless,” says John Harte, a professor of the Graduate School in Berkeley’s Energy and Resources Group. Harte, who conducted pioneering work on the “feedback” effect a warming climate exerts on natural carbon cycles in high-altitude meadows, observes that carbon sinks were poorly understood 35 years ago. “But we now know they absorb 18 billion tons of CO2 a year. Realistically, we should be putting more of the money we’re devoting to the development of carbon sequestration technology into enhancing natural carbon sinks. At the very least, we need to stop their degradation.” Harte’s work in the Colorado Rockies entailed artificially heating plots of land and tracking changes in vegetation types and carbon sequestration rates. In plots that weren’t heated and experienced climate change in real time, he found that wildflowers dominated, cycling large volumes of carbon into the soil during the short alpine growing season; when the plants died back each fall, the rate of carbon storage dropped off dramatically. But as Harte warmed specific plots over a period of years, woody shrubs replaced the flowering annual plants earlier than on nonheated land. These slower-growing plants sequestered carbon at a much slower rate than the wildflowers. “The ‘money,’ the carbon, in the bank account shrinks,” says Harte. But after about 100 years, you begin to see dividends. “The carbon coming into the soil from woody plants is stored longer, so you eventually still have carbon in the soil.” The goods news: This suggests natural sinks could be managed for optimal storage. But if emissions remain high, they’ll strain and ultimately overwhelm the sequestration capacity of the sinks, negating their value. “If climate change continues, if we don’t cut back on emissions,” says Harte, “there’ll be no way to buffer the effects.” And really, that’s the crux of the whole issue. At this point in the climate change crisis, we know what we must do to turn things around. Even better, we have the technologies and techniques to do it. But we need to deploy them. That means everything: solar in all its forms, from rooftop panels to orbital microwave arrays; wind turbine farms, both on land and at sea; fusion reactors; fission reactors; microgrids; massively distributed storage systems. And we must enhance, not debase, the natural systems that sequester carbon. We need to plant many more trees and manage working forests more sustainably, calculating carbon storage as a product equal to or exceeding board feet of lumber. And we need to protect the greatest carbon sink of them all: the ocean. “I’m terribly worried about the trend toward seabed mining,” says Kammen. “It’s the least regulated of all the new frontiers, some very large companies are pushing it, and it’d be absolutely devastating. If we don’t stop activities like that and if we don’t use all the sustainable energy options that are available, we are risking extinction.” That may not be a very optimistic note to end on, but then, optimism only gets us so far, doesn’t it? What we need now is grit and determination.

Elon Musk says ‘population collapse’ is a bigger threat than climate change. Is he right?


Elon Musk says 'population collapse' is a bigger threat than climate change. Is he right?

At the Cannes Film Festival this summer, many attendees reveled at the "Top Gun" reboot, a throwback to the past. But on the sidelines a smaller crowd witnessed something more solemn: the possibility of a dark and tragic future. "Plan 75," a film by Japanese director Hayakawa Chie, explores the potential dangers of her country's aging society, where nearly one-in-three people are currently 65 or older. Set in a near-future dystopia, the film depicts a nation whose healthcare and pensions systems have become so overburdened by the elderly that the government aggressively markets a policy to pay for final bucket list items and then euthanize anyone over 75. While technically the stuff of science fiction, demographers say the film arrives at a time when humanity really is aging. The global fertility rate has decreased by half since 1960. In countries responsible for 85% of the world's gross domestic product – the United States, Germany, Japan, even China and India – births have fallen below the “replacement rate,” meaning that unless offset by immigration, population will begin to decline as older generations depart. The United Nations calculates the world population will now peak in 2084, before starting to fall by the century's end.
An elderly man walks by an electronic stock board of a securities firm in Tokyo, Friday, Aug. 19, 2016. Japan is the world's oldest country, with 3-in-10 people over the age of 65.
An elderly man walks by an electronic stock board of a securities firm in Tokyo, Friday, Aug. 19, 2016. Japan is the world's oldest country, with 3-in-10 people over the age of 65.
In a world where economies are designed around growth and social systems depend on the young supporting the old, forward thinkers are beginning to wonder what comes next. Consider Elon Musk, Tesla CEO and business magnate, now most prominent among their ranks. “Population collapse due to low birth rates is a much bigger risk to civilization than global warming,” Musk wrote on Twitter this summer. “Mark these words.” But is he right?

Population concerns are nothing new

For centuries, humans have pondered the ideal size of humanity. But experts warn such efforts usually end in folly, and that our species has within its grasp solutions to prosper whether populations rise or fall. “It's up to us and how the world responds,” said Lauren Johnston, a professor at the University of Sydney's China Studies Centre and economic demographer. For much of the last few centuries, those fretting about overpopulation have had the spotlight. In 1798, English scholar Thomas Malthus published an influential essay that laid out an idea known as the “Malthusian trap,” which holds that population growth inevitably exceeds food and other resources, leading to famine and poverty. The work inspired anxiety in England and helped lead to the first national census of England, Scotland and Wales. Such concerns echoed loudly in 1968, when Stanford University professor Paul Ehrlich and wife Anne Ehrlich published "The Population Bomb," a book that predicted global famine leading to the deaths of hundreds of millions of people within decades. But most experts say such predictions have not come to pass. Particularly in the past 50 years, a “Green Revolution” in agriculture has used new farming methods to reap more calories per acre of land, leading world hunger to decrease even as the population doubled. Although studies show such practices have created additional problems – driving water pollution, contributing to climate change, and perhaps even decreasing the nutritional value of food – Johnston points out that many nations are now facing the opposite of starvation. “In most countries there has been a sufficiently productive response to population growth that there hasn't been a famine,” Johnston said. “Now there's obesity.”

Underpopulation on the horizon?

As concern over having too many mouths to feed has waned, an opposing one has risen: too few people to work. That's an especially obvious worry in China, which infamously implemented a one-child policy in 1980 to address exponential population growth projections. Its current population of 1.4 billion remains the world's largest. But realizing the aging trajectory of its society, in 2016 China eliminated the policy and has also limited pensions and social programs for the elderly, Johnston said.
Chinese children hold flags during a rehearsal prior to the opening of the Forum on China-Africa Cooperation (FOCAC) 2018 Beijing Summit on Sept. 3, 2018 in Beijing, China.
Chinese children hold flags during a rehearsal prior to the opening of the Forum on China-Africa Cooperation (FOCAC) 2018 Beijing Summit on Sept. 3, 2018 in Beijing, China.
Many other nations are or soon will be facing similar challenges. To maintain a steady population without immigration, a nation has to achieve a fertility rate of 2.1 children per woman, experts say. But the fertility rate is just 1.7 in China and Brazil, 1.5 across the European Union, and 0.8 in South Korea, the lowest of any country, according to the World Bank. The rate is 1.6 in the United States, where the population is still rising only due to longer lifespans and immigration, which is projected to outpace natural births by 2030. Globally, it's primarily African nations like Nigeria, where the fertility rate is 5.2, that are contributing to population growth. But as those nations develop, some experts expect fertility rates to fall as well, contributing to the possibility of unprecedented global population decline. “There's never been anything close to a parallel,” Johnston said. Some experts are ringing alarm bells on what that could mean for societies. In their book "Reversal: Ageing Societies, Waning Inequality, and an Inflation Revival," economists Charles Goodhart and Manoj Pradhan warn of mounting fiscal crises, "as medical, care, and pension expenditures all increase in our ageing societies." Nations could wind up burning the candle at both ends: as a higher percentage of people become retirees they require more public resources, while at the same time the taxable working population shrinks. Problems could be exacerbated as rates of Alzheimer's and other costly elder illnesses increase, while labor shortages create inflationary pressures. As countries face these challenges, their societies and politics could destabilize. "Our view of the future is not encouraging, but it is coherent and plausible," Goodhart and Pradhan write.

So Musk is right?

Not so fast, says Daniel Kammen, a professor of sustainability at the University of California, Berkeley and former Science Envoy to the U.S. State Department. While aging societies do pose possible challenges in the future, Kammen says the world is facing a current full-blown crisis right now: climate change. And adding more people to the Earth's population will only further complicate humanity's lagging efforts to fight global warming, experts say. “There's no ideal number, but certainly I would say there are too many people on our planet for our current lifestyle,” Kammen said. Kammen believes the entire conversation about population is a red herring, a view commonly held among population experts. Instead, he says the focus should be on whether or not countries are wisely using resources. That's when the wealth of nations like the U.S., and not their population, come into focus. A study in the journal Nature Sustainability this year found that the world's wealthiest 10% of people produce 47% of its carbon emissions, compared to just 10% of emissions for the entire bottom half of the economic ladder. To put it another way, World Bank data shows the average Nigerian's carbon footprint is 0.6 metric tons each year. With the globe currently emitting about 34 billion metric tons of CO2 annually, that means it could currently support 58 billion people if they had a Nigerian carbon footprint. On the other hand, the average American uses 14.7 metric tons of CO2 each year, meaning the world could support just 2.3 billion people if everyone had an American footprint. The same effect can be seen within countries. While many Americans believe that population-dense cities hold the most blame for carbon emissions, work from Kammen and his colleagues show the carbon footprints of urban Americans are actually substantially less than rural residents, with suburban residents surpassing both. That's true both on a per capita basis and in total: about half of U.S. carbon emissions come from suburban settings, while less than a third come from urban. Ultimately, Kammen said, the question is how to reduce resource footprints, especially in wealthy nations. The smaller they get, the more people the planet can support. “While it sure seems like there are a lot of people on our planet, our individual impact is much more measured by the ways in which we amplify or minimize our footprint,” Kammen said. “If you make it about population, you avoid how critical our patterns of consumption are.” Experts also say the challenges of population decline are not insurmountable. Johnston says it will come down to smart planning and cooperation. If populations do peak and fall, governments can mitigate the repercussions by sharing resources more equitably. That will likely include sacrifices among the older generations. Not with their lives as "Plan 75" depicts, but through higher retirement ages and adjustments to pensions and benefits. Other experts note that it may be possible to maintain productivity levels with fewer people, through increased education or even possibly with the assistance of technologies like Artificial Intelligence and automation. In the end, people of working ages may also need to sacrifice in the form of higher taxes. But such a future will inevitably look different than the world we live in now, and Goodhart and Pradhan warn a lot will be riding on whether or not societies accept such changes. "We doubt that politicians, facing rising health and pension costs, will be prepared or able to raise taxes enough to equilibrate the economy via fiscal policy," they wrote.

Population 'cures' can be worse than population collapse

While population decline comes with challenges, experts warn that attempts to reverse course are often at best ineffectual, and at worst hateful and destructive. After all, they note, the basis of population decline is personal freedom. Reiner Klingholz, a population researcher and author based in Germany, notes that smaller families and a more developed lifestyle often go hand-in-hand. As a society becomes wealthier and more educated, its fertility rate invariably falls. That's particularly tied to women's education and empowerment. When women become more educated, both professionally and on sexual reproduction, they are presented with life choices beyond homemaker and often choose to have less children, experts say. Development also brings increased wealth, which creates societies that are overall healthier and happier, even if the fertility rate is lower. “Look at Sweden and Denmark,” where fertility rates stand at 1.7, Klingholz said. “People are very happy in these countries.” Also troubling: Concerns about population decline often boost xenophobia. In the United States, "Great Replacement Theory" – an unfounded conspiracy that political leaders are intentionally replacing white Americans with non-white immigrants –   has moved from extreme right-wing circles into mainstream discourse. Perhaps nowhere is this tension more apparent globally than in Hungary, where the government of Prime Minister Viktor Orban is now offering about $30,000 and a raft of subsidies on homes and cars for Hungarian families with at least four children, while opposing new immigration. “Instead of just numbers, we want Hungarian children. Migration for us is surrender,” Orban said in 2020. Such rhetoric stands in stark contrast to most economists, who according to Goodhart and Pradhan, value immigration as a tool to offset population decline and boost a country's workforce and productivity. Attempts to instead fix population decline through economic policies like tax incentives often fail due to the ties between women's empowerment and lower fertility rates, said Per Espen Stoknes, director of the BI Centre for Sustainability and Energy at the Norwegian Business School. “Men can't tell women how many children they should have,” Stoknes said. “It's not really about the issue of (resources). It's really about what kind of life do women want for themselves?”

A happier future?

Johnston says that in the end, population decline doesn't have to be a crisis. Ultimately, as with climate change, it comes down to wise resource allocation. If humanity can cooperate and efficiently distribute resources through immigration and economic policies, it could build a world with where people are fewer but more educated, and in which productivity and ingenuity still flourish. But that's a big "if." “It might be so much healthier if there's a smaller population overall, but much more cooperation,” Johnston said. “If China goes from 1.4 billion people to 800 million, but people go from peasants to middle class, how on Earth is that going to be a bad shift?” Kyle Bagenstose covers climate change, chemicals, water and other environmental topics for USA TODAY. He can be reached at or on Twitter @kylebagenstose.

Evaluating cross-​​sectoral impacts of climate change and adaptations on the energy-​​water nexus: a framework and California case study

Electricity and water systems are inextricably linked through water demands for energy generation, and through energy demands for using, moving, and treating water and wastewater. Climate change may stress these interdependencies, together referred to as the energy-water nexus, by reducing water availability for hydropower generation and by increasing irrigation and electricity demand for groundwater pumping, among other feedbacks. Further, many climate adaptation measures to augment water supplies—such as water recycling and desalination—are energy-intensive. However, water and electricity system climate vulnerabilities and adaptations are often studied in isolation, without considering how multiple interactive risks may compound. This paper reviews the fragmented literature and develops a generalized framework for understanding these implications of climate change on the energy-water nexus. We apply this framework in a case study to quantify end-century direct climate impacts on California’s water and electricity resources and estimate the magnitude of the indirect cross-sectoral feedback of electricity demand from various water adaptation strategies. Our results show that increased space cooling demand and decreased hydropower generation are the most significant direct climate change impacts on California’s electricity sector by end-century. In California’s water sector, climate change impacts directly on surface water availability exceed demand changes, but have considerable uncertainty, both in direction and magnitude. Additionally, we find that the energy demands of water sector climate adaptations could significantly affect California’s future electricity system needs. If the worst-case water shortage occurs under climate change, water-conserving adaptation measures can provide large energy savings co-benefits, but other energy-intensive water adaptations may double the direct impacts of climate change on the state’s electricity resource requirement. These results highlight the value of coordinated adaptation planning between the energy and water sectors to achieve mutually beneficial solutions for climate resilience. Unknown-1

An Earth Day message for California: Move faster on climate change

imageLos Angeles Times by Sammy Roth For the original, click here. If there’s one thing to understand this Earth Day about California’s role in confronting the climate crisis, it’s this: Just because the state considers itself a global leader doesn’t mean it’s doing nearly enough. Gov. Gavin Newsom admitted as much last year. As monstrous wildfires carved a path of destruction from the giant sequoias of the Sierra Nevada to the mountains around Los Angeles — bringing smoke-choked orange skies to the Bay Area and raining ash to Southern California — Newsom said, “Across the entire spectrum, our goals are inadequate to the reality we’re experiencing.” “We’re going to have to do more, and we’re going to have to fast-track our efforts,” Newsom told reporters as he stood among freshly charred trees in Oroville. “While it’s nice to have goals to get to 100% clean energy by 2045, that’s inadequate.” Now leading scientists are offering the governor a far more aggressive path forward.

That path is laid out in a not-yet-published paper (available on arXiv) from a team of researchers led by UC Berkeley’s Daniel Kammen, whose work for an international climate science panel helped earn a Nobel Peace Prize. The researchers make the case that California must ratchet up its ambitions dramatically, and immediately. The scientists call for the state to reduce its planet-warming pollution nearly 80% by 2030, rather than the currently mandated 40%, through what they describe as a “a wartime-like mobilization of resources.” Why should the Golden State double its efforts? The paper rattles off a dizzying series of facts about the climate consequences already confronting Californians: 4.3 million acres burned in 2020, about 4% of the state; nearly $150 billion in health and economic damages from smaller firestorms two years earlier; and conflagrations so bad experts didn’t expect to see them for another 30 years. Not to mention worsening droughts, rising seas and hotter heat storms that are far deadlier than many people realize. And despite the state’s long track record of leadership in phasing out fossil fuels, it’s now falling behind, the researchers say. There’s no better sign of that than President Biden — once viewed with extreme skepticism by climate activists — trying to pass an infrastructure bill that sets a national goal of 100% clean electricity by 2035, a full decade ahead of California’s target.
Los Angeles Mayor Eric Garcetti delivers his annual State of the City address from Griffith Observatory on April 19, 2021.
Los Angeles Mayor Eric Garcetti delivers his annual State of the City address from Griffith Observatory on April 19, 2021.
Los Angeles Mayor Eric Garcetti endorsed the same 2035 goal in his State of the City address on Monday. That followed the release of a first-of-its-kind study by the federally funded National Renewable Energy Laboratory finding L.A. can achieve 98% clean energy as early as 2030, and 100% by 2035, without increasing the risk of blackouts or disrupting the local economy. Garcetti said in an interview that Newsom and the state Legislature should “absolutely” follow L.A.'s lead. “This should encourage California to see that it’s achievable everywhere. If the biggest city in the state with the largest municipal utility in the country can do this, you can do it too,” Garcetti said. “The reason why is obvious. This whole world, governments are missing their goals. Weather events are becoming more extreme, and the threat is greater today than it was yesterday,” he said. There are other examples overseas of governments picking up the pace. The United Kingdom plans to ban the sale of gas cars by 2030, half a decade ahead of Newsom’s deadline for California. British Prime Minister Boris Johnson recently set a target of slashing carbon emissions 68% by 2030, far more aggressive than California’s aim. Volvo says it will produce only electric vehicles by 2030. Finland is aiming for a carbon-neutral economy by 2035, 10 years ahead of California. Lawmakers in Washington state also vaulted ahead of California last week, setting a goal to end the sale of gas cars by 2030. “There’s a lot going on that we’re not taking advantage of,” Kammen said in an interview. Kammen has previously served as a Coordinating Lead Author for the United Nations-backed Intergovernmental Panel on Climate Change. His coauthors on the new paper include UC Merced cognitive scientist Teenie Matlock; USC sociologist Manuel Pastor; UC Santa Barbara sociologist David Pellow, UC San Diego climate scientist Veerabhadran Ramanathan; UC Santa Barbara political scientist Leah Stokes; and Tom Steyer, the billionaire climate activist who ran for the Democratic presidential nomination last year. The group used a modeling tool developed by the Climate Center, a Santa Rosa-based nonprofit, to analyze how much the Golden State could cut emissions over the next nine years without causing energy costs to rise significantly. They determined a reduction of 77% below 1990 levels was feasible, largely because solar panels, wind turbines and batteries are getting so cheap. “We didn’t work back from a target. We worked forward from what are the current price declines we’re seeing on the renewable and storage side,” Kammen said in an interview. “The 80% comes in at a sweet spot, where the prices don’t rise that much.”
The Los Angeles Department of Water and Power’s Pine Tree Wind and Solar Farm in the Tehachapi Mountains of Kern County.
The Los Angeles Department of Water and Power’s Pine Tree Wind and Solar Farm in the Tehachapi Mountains of Kern County.
What would those changes look like in practice? Under one pathway laid out in the paper, which is being reviewed by the journal Environmental Research Letters, California would need to reach 100% clean electricity by 2030. That would require building new infrastructure — including lots of offshore wind turbines — at a pace Kammen described as “a bit scary.” Emissions from transportation, the largest source of climate pollution, would need to fall by 70% in nine years, almost certainly necessitating an end to the sale of gas cars sometime this decade. “It’s really designed to be a wake-up call,” Kammen said. There’s little question a wake-up call is needed. The National Oceanic and Atmospheric Administration reported this month that concentrations of carbon dioxide and methane, the two most important greenhouse gases, reached record levels in 2020, rising rapidly despite a pandemic that slowed the global economy. The planet is already 1.2 degrees Celsius warmer than it was before the Industrial Revolution, nearing the 1.5 degrees that scientists have set as a target for staving off dangerous tipping points.

9/​18/​2020: KQED Newsroom, “Climate change and the economic outlook”

To watch the interview and discussion video, click here on the KQED website. Fighting Climate Change Amid Wildfires, Extreme Weather and Presidential Denial Screen Shot 2020-09-19 at 2.39.35 PM On Monday, during a trip to California, President Trump refused to acknowledge the role climate change has played in generating wildfires that have burned more than 3 million acres and killed at least 26 people, including one firefighter battling the El Dorado Fire east of Los Angeles. Trump asserted that poor forest management was to blame and that the weather would get cooler. But Trump’s denial of climate change is at odds with public opinion. According to the Yale Program on Climate Change Communication, more than 70% of Americans believe that climate change is happening, and nearly 60% believe that it is mostly due to human activities. Meanwhile, California remains a leader on fighting greenhouse gas emissions, with more than 30% of its energy coming from renewables like solar and wind, a figure that is mandated to double in a decade. Last week, Gov. Gavin Newsom said the state would accelerate its climate change strategies, including a goal to get to 100% carbon-free electricity by 2045. Guests:


Berkeley Conversations: Climate Change and Covid-​​19, can the crisis shift the paradigm?

April 27, 2020.  To watch the webinar, click here. Screen Shot 2020-05-05 at 10.40.18 AM

A panel of UC Berkeley experts discussed Monday what effect COVID-19 is having on the environment. (UC Berkeley video)

Ever so slowly, communities around the globe are cautiously easing shelter-in-place orders, and people are heading back to work — bringing with them damaging behaviors that hurt the environment and impact climate change, such as increased reliance on single-use plastic grocery bags.

But it doesn’t have to be that way, say four UC Berkeley environmental and energy experts. Instead, they say, the current COVID-19 pandemic offers lessons in how shared global solutions can help beat back the continued threat of climate change.

“We can restart the economy and put people back to work, and we have to do so in a way that we’re taking advantage of where renewable energy is today — then there’s a really positive opportunity,” said Dan Kammen, professor and chair of the Energy Resources Group and professor of public policy and nuclear engineering. “We have to put people back to work in a way that’s equitable and green.”

Disposable plastic bags have made a comeback as people have grown leery of being too close to other people and their possessions. In a number of cities and states, including San Francisco, new bans on plastic bags have been delayed or existing bans have been temporarily halted and customers ordered not to bring into shops their own bags, mugs or reusable items from home.

Kammen, along with colleagues David Ackerly, dean of the Rausser College of Natural Resources, Kate O’Neill, professor of environmental science, policy and management, and Valeri Vasquez, a Ph.D. candidate in the Energy and Resources Group, were part of a Berkeley Conversations panel that examined on Monday how the pandemic has caused seismic shifts in how we produce and consume goods and could also open a path to a more sustainable future.

“Right before the outbreak, we were actually starting to feel like we could make a real difference in terms of getting rid of single-use plastics and solving a lot of the issues with global waste streams,” O’Neill said. “But for any of us who’ve been in the Berkeley Bowl parking lot recently, one of the first things we might have noticed is a lot more litter. Plastic bags, rubber gloves, masks. This is something we’re going to have to push back on and really question. The main problem coming up is going to be reinstating zero waste policies once (the pandemic) is over.”

Vasquez underscored how the COVID-19 pandemic is revealing deep societal inequities and also demonstrating the interconnectedness of health, climate and sustainability issues.

“The public health and climate debates are really inextricably linked,” she said. “In our highly connected world, a disease that originated 3,000 or 6,000 miles away can be at our doorsteps in a day or less. So, the way that we mobilize against COVID-19 needs to be reflected in the way that we mobilize against that other big global affliction called climate change.”

Berkeley Conversations: COVID-19, are a series of live, online events featuring faculty experts from across the UC Berkeley campus who are sharing what they know, and what they are learning, about the pandemic. All conversations are recorded and available for viewing at any time on the Berkeley Conversations website.

CLR 2020 Workshop: Tackling Climate Change with Machine Learning

Click here for conference details: April 26.   Many in the ML community wish to take action on climate change, yet feel their skills are inapplicable. This workshop aims to show that in fact the opposite is true: while no silver bullet, ML can be an invaluable tool both in reducing greenhouse gas emissions and in helping society adapt to the effects of climate change. Climate change is a complex problem, for which action takes many forms - from designing smart electrical grids to tracking deforestation in satellite imagery. Many of these actions represent high-impact opportunities for real-world change, as well as being interesting problems for ML research. Screen Shot 2020-04-09 at 4.01.05 PM    

Social Distancing? You Might Be Fighting Climate Change, Too

In The New York Times, March 13, 2020:

As the nation shifts abruptly into the fight against coronavirus, a question arises: could social isolation help reduce an individual’s production of greenhouse gases and end up having unexpected consequences for climate change?

The biggest sources of carbon emissions caused by our lifestyles come from three activities, said Kimberly Nicholas, a researcher at the Lund University Center for Sustainability Studies in Sweden: “Any time you can avoid getting on a plane, getting in a car or eating animal products, that’s a substantial climate savings.” Many people trying to avoid the coronavirus are already two-thirds of the way there.

Dr. Christopher M. Jones, lead developer at the CoolClimate Network, an applied research consortium at the U.C. Berkeley Renewable and Appropriate Energy Laboratory, said that “all these extra precautions that schools and businesses are taking to keep people home are saving lives, and that’s clearly what’s most important.” Having said that, he added that many of the actions people are taking in response to the coronavirus outbreak could have a benefit of a reduced carbon footprint — though others would have little effect or could even expand it.

Screen Shot 2020-03-13 at 4.59.39 PM

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