NEWS 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.

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