The causes of California’s megafires: Climate change or 150 years of Euro-American mismanagement? Yes and yes.

In a very frank and data-rich webinar, fire ecologist Hugh Safford (USDA Forest Service and research faculty at Department of Environmental Science and Policy at UC Davis) offers “Some ruminations on fire and vegetation trends in California”. He explains the causes of the dramatic increase in megafires and what can be done about it.

A 2,500 year-old tree at Sequoia National Park now needs protection from fires.

The webinar was co-sponsored by the Yolo Interfaith Alliance for Climate Justice and Cool Davis and presented on May 5, 2021.

Safford’s presentation starts at 13:23 of the video. The equally enlightening Q&A session begins at 48:20.

Here is a summary of some of the key points:

  • The annual burned area has been rising rapidly since the 1980s, almost entirely in northern California.
  • This is largely due to fire exclusion caused by the removal of Native Americans as land managers and increased drought and record vegetation dryness caused by climate change.
  • Since 1999, burning over a million acres/yr now occurs regularly; this had not happened before 1999.
  • Pre-EAS (Euro-American Settlement) burning by Native Americans totaled up to FOUR million acres/year (but these were low severity fires that primarily burned the understory and smaller trees).
  • “Euro-Americans, when they showed up in the 1850s, and for that matter today, had no idea how important fire was to the functioning of these ecosystems and they feared it and felt like it was something they needed to stop. After a hundred years of that, it’s really biting us in the butt now because now we have jungles of fuels, we’ve cut most of the big fire-resilient trees out of the system, and when we get the ignitions start we can’t stop the fires anymore. Until about the 1990s, it was easy to put fires out in the forests.”
More mature trees are burning; the acres burned by high severity fires (where more than 90% of trees die) have increased 7x since 2001 in northern Sierra Nevada. 35% of the area of current fires are severe (burn most of the trees); under regular Native burning, this was 5-15%.
  • Pre-EAS forests were at least 40% old growth; current forests are only 6% old growth and highly vulnerable to high severity fires, as they are 4-5x denser than pre-EAS.
  • “Every single fire projection we found in the literature predicts bigger fires, more fires, and more severe fires, basically until we’ve burned so much of California that there actually isn’t much woody vegetation left to burn.”
  • Expect the loss of conifers and an increase in non-native grassland.
  • Changes already underway: loss of blue oak woodland, ponderosa, yellow pine, and subalpine pine; increase in hardwoods. Loss of sage scrub and chaparral in southern California. Many burned areas are quickly invaded by non-native grasses and will not recover. Incense cedar and white fir may become more dominant trees in California forests.
  • Fires in the Coast Range are now destroying chamise and blue oaks with limited evidence of re-sprouting.
  • In the short run, there’s not a lot we can do to manage climate, but there’s a lot we can do to manage fuels.
  • There’s been a huge renaissance, especially among Native tribes, to use controlled burns to manage forests. California’s new fire resilience plan supports the use of controlled burns. Northern Australia has had great success allowing Aboriginies to manage forests. Opportunities are limited, however, because of development.
  • The combination of drought cause megafires in the Sierra to produce “Hiroshima-type landscapes”, burning old growth.
  • How to stop fires: Forest thinning is critical, but it’s not economical to harvest small trees, so the government will have to subsidize it. For example, we can use the cut trees for biomass energy, as it done in Scandinavia. This is the only way to save large old growth trees and healthy forests.  “We have to cut a lot of trees. We don’t have a choice…. We can create forests that can handle large fires, or we can sit around and watch it all vaporize.”

Goodbye California: Reminiscences of a climate refugee

There are a lot of reasons why I’m moving from California to Washington, including family and other personal considerations. But one reason, one big reason, is California’s rapidly changing climate.

It was late February in the Coast Range of northern California when I was wearing shorts and a t-shirt. Dust swirled around my car in the dirt parking lot at Cold Canyon. The car thermometer, warmed by a sun that felt imported from Palm Springs, said 87 degrees; it was actually only 77. A hint of ash, omnipresent since The Fire last summer, remained in the air.

Its oaks torched with little hope of return, Putah Creek Canyon is quickly resembling a sun-scorched canyon in Arizona. Until 2018, only one fire in the area had burned more than 15 square miles. Then the County Fire burned 140 square miles. In 2020, the LNU Complex Fire burned 570 square miles.

The hillsides were green with the new growth of non-native grass, which was responding to a recent heavy rain. That was deceptive. More than half the rain we’d had in the previous eight months came in that single event. We had six inches of rain in all of 2020. Looking beyond the grass, nearly every tree – blue oaks and gray pines – on the hillsides was dead, burnt black and orange monuments to a previous era. For our local blue oak woodland, that era ended last year and, given that recruitment of saplings is unlikely due to heat, fire, and cattle, it was an era that will never return.

Massive die-offs are eliminating blue oaks from the southern third of their range. Black oaks are marching up the Sierra, displacing Ponderosa pine, which are marching up, displacing firs. Everyone is on the move. Oak woodlands are becoming oak savannahs, oak savannahs are becoming grasslands, grasslands are becoming rocky high deserts. Arizonification is happening quickly, thru heat, drought, and ultimately, thru fire.

Virtually all of the east slopes of the Coast Range between San Francisco Bay and the Trinity Alps has burned in the past ten years. In the Sierra, one can practically predict where the next fire catastrophe will happen, because it hasn’t burned yet (hint: Lake Almanor, Placerville, Arnold).

The Fire, the LNU Complex Fire, was part of 2020’s 4.3 million acres of scorched earth. The LNU Fire exceeded the total acreage of all previous fires that impacted my county over the last 50 years combined.

It was a beautiful day—for April. But February has become April, April has become May, and June, July, August, September, and even October and November have become unrecognizable. Every year more heat records are broken. Hottest summer, hottest month, most days over 100, most days over 90. The list goes on, each year breaking the records set the previous year. Weather data is normally highly variable; now it is a straight line—warmer and warmer. And smokier.

My cape honeysuckle and bougainvillea, both planted with a degree of optimism outside their recommended zone, used to die back so badly in the winter that each spring I was tempted to declare them dead and pull them out. Now they bloom year-round, looking like they’re in a courtyard at a hotel in the tropics. We haven’t had a real freeze in seven winters.

The songs of lesser goldfinches on my street are a depressing warning. I can’t take two steps outside without seeing or hearing a bird that reminds me that our climate has seriously changed. Western tanagers, house wrens, and turkey vultures are regular in winter now. The lesser goldfinches have come out of the arid hills and are quickly becoming one of the most ubiquitous nesting birds in Davis. (I know this definitively because one included an imitation of a canyon wren in its song.) What’s more, at least four Say’s phoebes, essentially a high desert species, are scouting for nests in town now. A fifth arrived on my block last week, singing as if on territory. They’ve been doing this for a few years and their numbers are growing.

The graphs of acres burned in California (and in other western states) and the expansion of some bird species into the Pacific Northwest (in this case, Anna’s hummingbirds in winter), are strikingly similar.

I’m leaving. I’ve lived in California fifty-five years but it’s no longer the state I grew up in.

We’re headed to the Olympic Peninsula in Washington. We are fortunate to be able to do so.

Besides the cooler summers, one of the best things about moving to a new place is that I won’t be reminded of climate change on a daily experiential basis. Because the ecosystem will be new to me, I won’t know what’s different, what is changing, except maybe for the brown boobies, a tropical seabird, that are now showing up in Puget Sound each year. Or the family of California scrub-jays that have just established residence on my new street. Like Anna’s hummingbirds, black phoebes, great egrets, red-shouldered hawks, and people like me, scrub-jays are moving north. I expect more of California’s birds to follow me, just as I follow some of them. Yes, lesser goldfinches are coming north too; they’re already established southeast of Tacoma.

I feel like a frog in a boiling pot. I’m getting out. I’m saying goodbye to California, but I feel it has left all of us without saying goodbye to anyone.

The view from Point Wilson, a mile from my new home in Port Townsend, which has had only a few nights below freezing all winter. Climate change is occurring there too, but remains well within temperate ranges.

I do believe that Homo sapiens may ultimately win the climate battle and bring atmospheric CO2 back down to 300 ppm or something. But that’s a hundred years off. And there’s no guarantee we can stop the tide of Greenland and Antarctic ice melt to prevent sea level rise. In the meantime, in the next 50 to 100 years, it’s going to get a lot warmer. And we may ultimately lose New York City, Singapore, Mumbai, and every other low-lying coastal city. My new home is fifty feet above sea level. Well, probably forty-nine and a half now.

The song of the Lesser Goldfinch: Another harbinger of a warming climate

As the climate warms, different thresholds are crossed for different species at different times. For the Lesser Goldfinch, that time seems to be now—both in the core and northern edges of its range, where the species is increasing, and in some parts of the southern arid regions, where it is decreasing.

As I prepare to migrate myself from Davis, California to Port Townsend, Washington, I’m serenaded by Lesser Goldfinches every time I step outside. This is a new thing, a warning of coming heat and smoke brought by a beautiful voice. A more open and arid country version of the American Goldfinch, until five or ten years ago, Lesser Goldfinches were sparse breeders in Davis. I would get a few of them mixed with Americans at my feeder in winter, but I’d have to go west to the more arid edges of the Sacramento Valley, or up into the hot dry foothills, to find them in the breeding season.

They arrived in my neighborhood as nesters about five years ago. This year, 2021, they seem to be the most ubiquitous singing bird, setting up terrorities throughout the town. Friends in Sacramento have reported the same. This comes after several years of record heat and lack of rain (only 6″ in all of 2020).

Here’s what the eBird data says. For comparison, Northern Mockingbird, one of the most common birds in town, is reported from about 20 eBird locations in Davis each June (ranging from 16 in 2015 and 14 in 2016 to 18-22 in the more recent years as eBird users and reports increased). Using mockingbird as a metric for Davis, it’d be fair to say that 20 sites represents close to 100% presence throughout the town, and that number was probably 25% lower (i.e. 15 sites) in 2015. Lesser Goldfinches have increased from reports from four sites in June of 2015 (representing about 20% of the town) to 17 sites in June of 2020 (representing 85% of the town). It feels like it will be 100% this year.

They are not the only arid-country species increasing in Davis as a breeder. Nesting Say’s Phoebes have expanded up from the south, with multiple pairs in Woodland each year (and it’s looking like Davis this year as well).

As with so many less-migratory species, Lesser Goldfinches are expanding north into the Pacific Northwest and beyond.  Their colonization of the Columbia River Valley began in the 1950s, with the first state of Washington record in 1951; they are now established around Portland, The Dalles, and in the vicinity of Clarkston on the Idaho border. They remain rare elsewhere, but increases in records have been dramatic in recent years. In the northern Puget Trough region (Chehalis north thru Puget Sound to Canada), June records have increased from 1 in 2015 and 2016 to 10 in 2020 (as reported on eBird). While they have clearly gained a toe-hold in Olympia and Puyallup in the South Sound region, in 2020 they made appearances in Victoria and Vancouver, Canada (not shown in the data because these records were in May, not June).

Lesser Goldfinches in British Columbia were limited to four scattered records until 2007. Since then, they have become nearly annual, with most records between January and June.

This is a pattern seen in other resident and less-migratory species. Many of those that were already growing before detectable climate change (around 1985) have expanded noticeably since then. Anna’s Hummingbird is the most dramatic example.

Further east, Lesser Goldfinches are moving due north from Yakima and Kennewick into the Okanagan Valley. June records in this region have increased from zero in 2015 to eight in 2020.

All this is predicted. The National Audubon climate prediction map for Lesser Goldfinch, under the 2C warming scenario, describes much of what we are witnessing.

In the Mojave Desert, Lesser Goldfinches have declined. Iknayan and Beissinger (2018) reported them from only 43% of 61 study sites, compared to 68% historically. This is part of a massive avian community collapse in the Mojave Desert, as extreme aridity is pushing many species beyond their limits.

The renewable diesel revolution: How California is reshaping world oil markets

Despite all the attention on the new Biden Administration’s efforts to combat climate change, one state, California, is reshaping the world’s oil markets through its progressive climate policies.

Most dramatic has been the state’s shift to renewable diesel (RD). Unlike its green cousin, biodiesel, RD is molecularly identical to conventional ultra-low-sulfur-diesel (ULSD), making it a “drop-in” fuel. No modifications to engines, gas stations or pipelines are needed. It can be mixed with conventional diesel seamlessly. It is made from bio feedstock such as vegetable and animal oils such as canola, soybean, and corn oil, used cooking oil, tallow, and even municipal solid waste; the exact recipe varies. Current production methods reduce carbon emissions 50 to 85% compared to conventional diesel. RD burns cleaner than conventional diesel, producing 30% less particulates. In addition to less air pollution, this also means less wear on engines.

A 20% RD mixture is called R-20. The ferry boats in San Francisco Bay are running on R-100. UPS, Amazon Prime, and Cherokee Freight Line trucks are now switching to RD, at least in California where the fuel is available. Internationally, cargo vessels with diesel-electric engines are adopting the fuel.

Many cities in California – Oakland, San Francisco, Sacramento, San Diego – now exclusively use RD in city-owned heavy-duty trucks, buses and equipment.

Renewable diesel already accounts for 20% of California’s diesel supply and is projected to grow well beyond 50% by 2024, expanding to include jet fuel, where it is called “sustainable jet fuel”. Renewable propane is also produced during the refining process. Renewable gasoline, unfortunately, is still not economically feasible.

California’s RD comes from a variety of sources. It is imported from Singapore (Neste) and North Dakota. At the latter, the Marathon refinery in Dickinson, North Dakota, originally built to refine fracked Bakken oil, has converted to taking soybeans to make RD for the California market.

The California Energy Commission has identified enough proposed RD projects to supply all of the state’s needs in the future.

Increasingly, refineries in California are ramping up to produce RD from local feedstock. Two of the state’s largest refineries, Phillips 66 and Marathon in the Bay Area, are currently closed, using the Covid downturn to retrofit their operations into making RD. They will each produce 20% of the state’s diesel in the form of RD; they will completely cease using crude oil as an input. Other smaller refinery conversions are underway in southern California.

The California Energy Commission (CEC) projects that the state’s overall oil use, already down 20% due to the pandemic, will scarcely rebound and then continue declining in the future.

Washington and Oregon are taking steps to increase RD supply in their states. (Phillips 66 had originally sought to convert their Cherry Point refinery near Bellingham, WA, to RD production but ran into permitting problems. They are now trying again.)

This is all being driven by a combination of federal and state laws. The federal government already offers a $1/gallon tax credit for conversion to renewable fuels. Since the credit is bankable and tradeable, it’s essentially real cash. The program is set to expire at the end of 2022 but is likely to be extended with bipartisan support.

At the state level, California’s ever-lowering cap of tradeable permits under the AB32 cap-and-trade program is finally biting hard enough to change incentives. Carbon credits are now yielding about 30 cents/gallon and is likely to rise. Because this comes from traded permits, it is not a direct payment from government funds.

Combining federal and state incentives, a refinery converting from conventional to renewable diesel reaps an additional $1.30/gallon. If the Phillips 66 project goes to its full 800 million gallons/year, that’s at least a billion dollars each year in subsidies – from tax credits and tradable carbon credit sales.

California has already reduced greenhouse gas emissions 15-20% since the peak in 2004. This has been achieved during a period of significant economic and population growth; emissions per gross domestic product are down about 45%. Because the transportation sector has been among the most challenging for reducing emissions, the RD revolution will go a long way to helping California reach net zero by 2050. The Biden Administration is using California’s carbon reduction measures as a model for the nation.

The RD revolution is a transition to more dramatic decreases in oil use due to electrification of the vehicle fleet.

Mojave Desert bird populations plummet due to climate change

Two recent papers concluded that many breeding bird species in southern California and Nevada deserts have declined dramatically due to climate change.

In their abstract, Iknayan and Beissinger (2018) summarized, “We evaluated how desert birds have responded to climate and habitat change by resurveying historic sites throughout the Mojave Desert that were originally surveyed for avian diversity during the early 20th century by Joseph Grinnell and colleagues. We found strong evidence of an avian community in collapse.”

They re-surveyed 61 sites originally surveyed by Grinnell teams in the early 20th century (primarily between 1917 and 1947).

Of 135 species assessed (which included some wintering and migrating species, as well as breeding species), 39 had significantly declined; only one (Common Raven) had increased. This was in stark contrast to similar assessments they conducted of Sierra and Central Valley sites, where more species had increased than decreased and there were no overall declines (not to say there weren’t winners, losers, and range shifts within those regions).

Figure 1B from Iknayan and Beissinger (2018). Every study site had fewer species than previously– on average each site had lost 43% of their species.

Detailed analyses suggested less rainfall and less access to water was the primary driver. Habitat change only affected 15% of the study sites and was of secondary importance. They found no evidence of expansion of species from the hotter, drier Sonoran Desert (e.g. Phainopepla, Verdin, Black-throated Sparrow) into the Mojave Desert.

Consistent with a community collapse, declines were greatest among species at the top of food chain — carnivores such as Prairie Falcon, American Kestrel, and Turkey Vulture. Insectivores were the next most impacted, and herbivores the least. But the declines affected both common and rare species, both generalists and specialists.

Figure 1B from Iknayan and Beissinger (2018), which I’ve augmented with species labels from the database available in the supplementary materials. Other significant losers (red dots), in order of degree of decline, included Western Kingbird, Western Meadowlark, Black-chinned Sparrow, Lawrence’s Goldfinch, Bushtit, Ladder-backed Woodpecker, and Canyon Wren. The yellow dots are newly invasive species: Chukar, Eurasian Collared-Dove, Eurasian Starling, and Great-tailed Grackle.

A follow-up study by Riddell et al (2020), also involving Iknayan and Beissinger, focused on the thermoregulatory costs — the water requirements to keep cool — for the declining species. They found that “species’ declines were positively associated with climate-driven increases in water requirements for evaporative cooling and exacerbated by large body size, especially for species with animal-based diets.” Larger species get much of their water from the insects they eat. They estimated larger species would have to double or triple their insect intake to meet their water needs, though insect abundance is lowest July thru September.

American Kestrels were among the biggest losers in the study, struggling to meet their cooling needs.

Intriguingly, they found that 22 species had actually declined in body size over the last century, consistent with Bergmann’s Rule, and had reduced their cooling costs up to 14%. These species fared better. Current climate change, however, is at least ten times more rapid than any previous warming event, during which many species evolved. They estimated cooling costs have already increased 19% and will reach 50% to 78% under most scenarios, far outstripping any species’ ability to evolve through the current rapid warming.

These results stand in stark contrast to the Pacific Northwest, where many of the same bird species (e.g. Anna’s Hummingbird, Turkey Vulture, Northern Mockingbird) are increasing. This is consistent with projections which generally show individual declines along species’ southern edge and expansions at the north edge of their range (see Audubon climate projection maps for individual species).

Iknayan and Beissinger conclude, “Our results provide evidence that bird communities in the Mojave Desert have collapsed to a new, lower baseline. Declines could accelerate with future climate change, as this region is predicted to become drier and hotter by the end of the century.”

Helping forests migrate: Planners race to plant trees adapted to the future climate

Researchers from UC Davis collect acorns in arid west Texas to plant on their campus in northern California. They estimate their climate in 2100 will be similar to that of Barstow or even Phoenix today. City staff from a town near Portland, Oregon travel to California and Arizona for seedlings they can take home and plant along their city streets. They are preparing for Portland’s weather to become like Sacramento today.

The range of Arizona oak. For one town near Portland, Oregon, the list of potential future street trees includes this species, as well as California buckeye, California laurel, and silverleaf oak.

With these regions breaking new heat records annually – Sacramento just topped 90 degrees for the 110th day (and counting) in 2020—and given that trees take decades to mature, the race is on. Birds can fly, mammals can walk, but trees expand their ranges very slowly. Most acorns from an oak end up within a few hundred yards from their home tree.

Climate velocity, the speed at which ecotones are shifting north, is much faster than that. Our climate is changing ten to one hundred times faster than during a global warming event 55 million years ago known as the Paleocene-Eocene Thermal Maximum (PETM). During that “rapid” spike, palm trees successfully migrated to the Arctic circle, but they had thousands of years to make it there.

Dead blue oaks in Fresno County, California. They experienced excessive mortality during the 2012-16 drought. These hills may revert to grassland. Researchers want to use the genes of the survivors as stock for the future in the north. For a full presentation of blue oak gene-assisted migration see this presentation by the California Department of Fish and Wildlife.

While trees can’t walk, they can die. Range contraction of trees along their southern xeric (dry) edge is happening in the American West right with the speed of climate change. Blue oak die-offs are widespread in the southern third of their range. From California to Colorado, conifers such as Ponderosa pine and Douglas-fir are disappearing from lower elevations. To quote Davis et al (2019), “In areas that have crossed climatic thresholds for regeneration, stand-replacing fires may result in abrupt ecosystem transitions to nonforest states.” When people talk about California becoming Arizona, the cleanup hitter in that process may be fire, but the first batters are heat, drought stress, and bark beetles. After fires, decreased soil moisture and increased vapor pressure deficit (VPD) associated with climate change are leading to reduced probability of regeneration (Davis et al 2019). In short, many forests are not coming back.

Ponderosa pines are disappearing from lower elevations of the Sierra in California. This has been documented in Colorado as well.

Range expansion of trees northward has been documented, but the pace is anemic, insufficient to keep up with the changing climate. One study in the east found that ranges in adult trees expanded north less than 150 yards per year (Sittaro et al 2017). They concluded, “our results add to the body of evidence suggesting tree species are mostly limited in their capacity to track climate warming…”

Recent mega fires include many of the drought-killed conifers in the southern Sierra. Research suggests regeneration may be imperiled due to a warming climate.

Researchers have discussed facilitating tree migration due to climate change for over a decade (Aitken et al 2008). For over a hundred years, botanists have recognized regional differences within the same plant species, and simple garden experiments have shown that local varieties do better. The standard rule of thumb has always been that local varieties are best; they are adapted to the local ecological niche. Now that is changing.

Recent research is showing that trees are now in the wrong places; the climate has shifted past them. Valley oaks, white fir, Douglas fir, ponderosa pine, Western hemlock, and lodgepole pine seedlings all do better when removed from their original home and moved north (Aitken and Bemmels 2015).

The local trees are becoming misfits in a world that is changing around them. Many researchers are hesitant to fully embrace assisted migration; introducing non-native species has a horrid track record. But they are beginning to study “assisted gene flow”, moving hardy trees from the southern end of a species’ range to the north end. Cities, on the other hand, are beginning to see trees as more than just aesthetically pleasing; they are critical infrastructure, providing shade and reducing urban temperatures. So the cities and towns are moving faster, boldly cultivating trees from the dry Southwest into the Pacific Northwest.

This photo from Aitken and Bemmels (2015) shows a series of Sitka spruce, all eight years old, planted together in British Columbia. The trees from the south, adapted for a warmer and drier environment, are out-competing the locals.

Tree migration is also critical for the range expansion of animals. Without the trees and other vegetation, many birds, mammals, and other forms of life have no habitat rungs on the ladder to enable them to move north as well. Anna’s Hummingbirds now winter in Canada and even Alaska, largely due to ornamental plantings. The Oak Titmouse, on the other hand, is dependent on oaks, tightly constraining its ability to expand north. It may be that, in the coming decades, oaks and other tree species planted in cities and towns will provide critical refugia for a wide variety of birds and insects seeking cooler climes.

Becoming Arizona: How climate change is transforming California thru fire

When climatologists predicted that Sacramento would have Phoenix’s weather by 2100, and Portland would have Sacramento’s, they didn’t explain the ecological implications nor the process. Yet it’s apparent that an awful lot of trees need to disappear for the Sierra to look like the rock, grass, and cacti that make up Camelback Mountain in Phoenix.

Camelback Mountain near Phoenix

A new “new normal” every year

This ecological transformation, the likes of which would normally take a thousand years even during a rapid warming event, is happening, driven by rapid climate change. All those trees are flying away in the form of ashes and smoke.

The process, in human and ecological terms, is brutal. Californians experience a new “new normal” each year, each one stunning in its own right. In 2017 we were shocked when 6,000 homes burned in Santa Rosa, killing dozens as people fled in their bathrobes. Despite decades of fires in suburban California, there had never been anything of that magnitude. Before the year was out, the Thomas fire became the largest in state history as it burned thru Christmas and New Year. The next summer, the Carr fire stunned us with an EF-3 firenado that generated 140 mph winds. A few months later, the past was eclipsed when the entire town of Paradise burned, killing 85 people. That may be the largest climate-induced mass mortality event in history.  

2020

After a reprieve in 2019, we arrive at 2020, where acreage burned has exceeded two million and three million for the first time. We keep having to adjust our vertical axes to make room for each new year. Five fires burning at the same time in 2020 qualified for the top 20 largest fires in the history of the state. Three of those, still burning as a write, are first, second, and fourth on the list.

California under smoke, September 9, 2020.

Each year has its macabre highlights. This year, over 300 people were rescued by military helicopters, many at night high in the Sierra. For the first time ever, all 18 national forests were completely closed to the public. The National Weather Service had to create a firenado warning. A dystopian pall of smoke created hazardous air from California to Canada for weeks, forcing people into their homes with all windows shut. And my hometown, Woodland Hills, hit 121 degrees, the highest temperature ever recorded in Los Angeles County.  

In 2019, the media reported that Oregon firefighters make an annual trek to California to provide mutual aid. In 2020, that changed. A quarter of the west slope of the Cascades from Portland to Medford appears to be on fire. One out of eight Oregonians are evacuating. The media is filled with horrific stories of grandmothers and teenagers burned alive while the father asks a badly burned woman along a roadside if he’s seen his wife. “I am your wife,” she responds.

Eugene, Oregon on the morning of September 8, 2020.

The process

We have heard for years that, with longer and hotter summers and declining snowpack, fire season has grown by months. In 2006, Westerling predicted such an increase in fires that the forests of the western US would become net carbon emitters. The US Forest Service now plans for fire year-round.

A series of academic analyses lays out the factors and processes of Arizonification. Decreased summer rains, as well as warmer winter and spring temperatures, are creating dry and stressed trees. But that’s not all. Summers that have become 1.4C (2.5F) warmer have led to an exponential increase in atmospheric vapor pressure deficit (VPD). It’s getting drier and, more importantly, vegetation is getting drier. This leads to big fires. Williams et al (2019) noted, “The ability of dry fuels to promote large fires is nonlinear, which has allowed warming to become increasingly impactful.” The Camp Fire, which destroyed the town of Paradise, occurred during some of the lowest vegetation moisture ever recorded. Add to that hot dry winds and vulnerable PG&E transmission lines, and the Paradise disaster looks predictable.

Northern California, being at western North America’s southern edge of the low elevation temperate forests, is especially at risk. As documented in the Verdugo Mountains near Los Angeles, high fire frequency converts forest and chapparal to weeds and rocks. That southern edge is pushing north. Forests are migrating north; so are deserts. (So are bird populations.)

To summarize, slightly warming temperatures, even in winter and spring, and less summer rain lead to an exponential increase in dry vegetation, which leads to an exponential increase in large fires, which leads a conversion of habitat from forest and chaparral to the grass and rock-dominated landscapes of arid desert mountain ranges. Sacramento becomes Phoenix. The Sierra and Coast Ranges become Camelback Mountain.

The future

Nearly the entire east side of the northern Coast Ranges have burned since 2018. Much of the southern Sierra forests died during the recent drought; most of those have yet to burn.

Arizona State University fire historian Prof. Stephen Pyne calls this a new epoch, the Pyrocene. “The contours of such an epoch,” he writes, “are already becoming visible through the smoke. If you doubt it, just ask California.”

Abatzoglou and Williams (2016) conclude, “anthropogenic climate change has emerged as a driver of increased forest fire activity and should continue to do so while fuels are not limiting.” Williams et al repeat this, “Given the exponential response of California burned area to aridity, the influence of anthropogenic warming on wildfire activity over the next few decades will likely be larger than the observed influence thus far where fuel abundance is not limiting.”

In layman’s terms, it’s going to get worse until there’s nothing left to burn.

The annual area burned in California has increased fivefold from 1972 to 2018 (Williams et al 2019). Several individual fires in 2020 exceed the average from 1987-2005. The point shown here for 2020 is still increasing.

Academic papers

Here is a partial list of recent research on the increase of fires in California and the western US.

Abatzoglou and Williams (2016). Impact of anthropogenic climate change on wildfire across western US forests. PNAS 113 (42) 11770-11775.

Goss et al (2020). Climate change is increasing the likelihood of extreme autumn wildfire conditions across California. Environmental Research Letters 15(9).

Haidinger and Keeley (1993). Role of hire fire frequency in destruction of mixed chaparral. Madrono 40(3): 141-147.

Holden et al (2018). Decreasing fire season precipitation increased recent western US forest wildfire activity. PNAS 115 (36) E8349-E8357.

Kitzberger et al (2017). Direct and indirect climate controls predict heterogeneous early-mid 21st century wildfire burned area across western and boreal North America. PLOS One.

Lareau et al (2018). The Carr Fire Vortex: A Case of Pyrotornadogenesis? Geophysical Research Letters 45(23).

Seager et al (2014). Climatology, variability and trends in United States 2 vapor pressure deficit, an important fire-related 3 meteorological quantity.

Swain (2020). Increasingly extreme autumn wildfire conditions in California due to climate change. Weather West Blog (related to Goss et al 2020 above).

Syphard et al (2019). The relative influence of climate and housing development on current and projected future fire patterns and structure loss across three California landscapes. Global Environmental Change 56: 41-55.

Williams et al (2019). Observed Impacts of Anthropogenic Climate Change on Wildfire in California. Earth’s Future 7(8): 892-910

Westerling et al (2006). Warming and Earlier Spring Increase Western U.S. Forest Wildfire Activity. Science 313(5789): 940-943.

The invasion of the Pacific Northwest: California’s birds expand north with warmer winters

Birds, because of their mobility, are considered to be fairly adaptable to climate change. They evolved in the aftermath of two of the world’s most catastrophic warming events (the K-T extinction and the Paleocene-Eocene Thermal Maximum), spreading to the Arctic, crossing continents, and evolving along the way. While those warming events took place over tens of thousands of years, the current warming is happening in the space of a couple hundred, with noticeable changes in climate within the lifespan of a single bird.

There will be winners and losers. Generalists, and species that enjoy warmer weather, are likely to be winners. Those with narrow food or habitat requirements, especially those dependent on the ocean or the Arctic/Antarctic, will likely be losers. Although counter-intuitive, it is primarily non-migratory resident species that seem to be more adaptable to a changing climate.

Recent studies

Studies of climate impacts on western North American birds using past data are limited, but some focusing on California were recently published. Iknayan and Beissinger (2018) showed that, over the last 50 years, “bird communities in the Mojave Desert have collapsed to a new, lower baseline” due to climate change, with significant declines in 39 species. Only Common Raven has increased. Furnas (2020) examined data from northern California’s mountains, showing that some species have shifted their breeding areas upslope in recent years. Hampton (myself) (2020) showed increases in many insectivores, both residents and migrants (from House Wrens to Western Tanagers), in winter in part of the Sacramento Valley over the last 45 years. These changes, particularly range shifting north and out of Southwest deserts, is predicted for a wide number of species.

The invasion of the Pacific Northwest

Here I use Christmas Bird Count (CBC) data to illustrate that some of California’s most common resident birds have expanded their ranges hundreds of miles north into Oregon, Washington, and British Columbia in recent years. The increases are dramatic, highly correlated with each other across a wide range of species, and coincide with rapid climate change. They illustrate the ability of some species to respond in real time.

In parts of Oregon and Washington, it is now not unusual to encounter Great Egret, Turkey Vulture, Red-shouldered Hawk, Anna’s Hummingbird, Black Phoebe, and California Scrub-Jay on a single morning—in winter. A few decades ago, this would have been unimaginable. Some short-distance migrants, such as Townsend’s Warbler, are also spending the winter in the Pacific Northwest in larger numbers.

The following graphs, showing the total number of individuals of each species seen on all CBCs in Oregon, Washington, British Columbia, and (in one case) Alaska, illustrate the range expansions. Adjusting for party hours scarcely changes the graphs; thus, actual numbers of individuals are shown to better illustrate the degree of change. The graphs are accompanied by maps showing predicted range expansions by the National Audubon Society, and recent winter observations (Dec-Feb) from eBird for 2015-2020.

These range expansions were predicted, though in some cases the recent trends exceed even projected scenarios under 3.0C increases in temperature.

Let’s begin with the climate. Canada as a whole has experienced 3.0C in temperature increases in winter. British Columbia has experienced an average of 3.7C increase in Dec-Feb temperatures since 1948. The greatest increases have been in the far north; increases in southern British Columbia, Washington and Oregon have been closer to 1.5C.

winter temps in Canada.jpg

Average nationwide winter temperatures deviation from average.

Great Egret

Great Egrets on Oregon CBCs have increased from near zero to nearly 900 on the 119th count (December 2018 – January 2019).

CLICK ON GRAPHS TO ENLARGE

GREG OR graph.jpg

But their expansion, which took off in the early 1990s into Oregon, is now continuing in Washington, with a significant rise beginning in the mid-2000s. Great Egrets occur regularly in southern British Columbia, but so far have eluded all CBCs.

GREG WA graph.jpg

They have not quite fulfilled the full range predicted for a 1.5C increase, but are quickly on their way there.

GREG maps.jpg

Turkey Vulture

Turkey Vultures began increasing dramatically in winter in the Sacramento Valley of California in the mid-1980s, correlated with warmer winters and a decrease in fog. Prior to that, they were absent. Now, over 300 are counted on some CBCs. That pattern has been repeated in the Pacific Northwest, though about 20 years later. Both Oregon and British Columbia can now expect 100 Turkey Vultures on their CBCs. Curiously, Puget Sound is apparently still too cloudy for them, who prefer clear skies for soaring, though small numbers are regular in winter on the Columbia Plateau.

TUVU CBC graph.jpg

TUVU maps.jpg

Red-shouldered Hawk

Red-shouldered Hawks have increased from zero to over 250 inviduals on Oregon CBCs, taking off in the mid-1990s.

RSHA OR graph.jpgTwenty years later, they began their surge into Washington. It’s a matter of time before the first one is recorded on a British Columbia CBC.

RSHA WA graph.jpg

While their expansion in western Washington is less than predicted, their expansion on the east slope, in both Oregon and Washington, is greater than predicted. This latter unanticipated expansion into the drier, colder regions of the Columbia Plateau is occurring with several species.

RSHA maps.jpg

Anna’s Hummingbird

If this invasion has a poster child, it’s the Anna’s Hummingbird, which, in the last 20 years, have become a common feature of the winter birdlife of the Pacific Northwest. Their numbers are still increasing. While much has been written about their affiliation to human habitation with hummingbird feeders and flowering ornamentals, the timing of their expansion is consistent with climate change and shows no sign of abating. Anna’s Hummingbirds are not expanding similarly in the southern portions of their range. The sudden rate of expansion, which is evidenced in most of the species shown here, exceeds the temperature increases, suggesting thresholds are being crossed and new opportunities rapidly filled.

ANHU CBC graph.jpg

The expansion of the Anna’s Hummingbird has now reached Alaska, where they can be found reliably in winter in ever-increasing numbers.

ANHU AK graph.jpg

The range expansion of the Anna’s Hummingbird has vastly outpaced even predictions under 3.0C. In addition to extensive inland spread into central Oregon and eastern Washington, they now occur across the Gulf of Alaska to Kodiak Island in winter.

ANHU maps.jpg

Black Phoebe 

Non-migratory insectivores seem to be among the most prevalent species pushing north with warmer winters. The Black Phoebe fits that description perfectly. Oregon has seen an increase from zero to over 500 individuals on their CBCs.

BLPH OR graph.jpg

With the same 20-year lag of the Red-shouldered Hawk, the Black Phoebe began its invasion of Washington.

BLPH WA graph.jpg

The figure below illustrates two different climate change predictions, using 1.5C and 3.0C warming scenarios. While nearly a third of the Pacific Northwest’s Black Phoebes are in a few locations in southwest Oregon, they are increasingly populating the areas predicted under the 3.0C scenario.

BLPH maps.jpg

Townsend’s Warbler

Migrant species tend not to show the dramatic range expansions of more resident species – and short-distance migrants show more range changes than do long-distance migrants. Townsend’s Warblers, which winter in large numbers in southern Mexico and Central America, also winter along the California coast. Increasingly, they are over-wintering in Oregon and, to a lesser degree, Washington. This mirrors evidence from northern California, where House Wren, Cassin’s Vireo, and Western Tanager are over-wintering in increasing numbers. These may be next for Oregon.

TOWA WA OR graph.jpg

Townsend’s Warblers are already filling much of the map under the 1.5C warming scenario, though their numbers on CBCs in Washington and British Columbia have yet to take off.

TOWA maps.jpg

California Scrub-Jay

Due to problems with CBC data-availability, I have no graph for the California Scrub-Jay. Their northward expansion is similar to many of the species above. Their numbers on Washington CBCs have increased from less than 100 in 1998 to 1,125 on the 2018-19 count. eBird data shows they have filled the range predicted under the 3.0C scenario and then some, expanding into eastern Oregon, the Columbia Plateau, and even Idaho.

CASJ maps.jpg

Other species

Other species which can be expected to follow these trends include Northern Mockingbird and Lesser Goldfinch. (See more on the expansion of the Lesser Goldfinch here.) White-tailed Kite showed a marked increased in the mid-1990s before retracting, which seems to be part of a range-wide decline in the past two decades, perhaps related to other factors.

Curiously, three of the Northwest’s most common resident insectivores, Hutton’s Vireo, Bushtit, and Bewick’s Wren, already established in much of the range shown on the maps above, show little sign of northward expansion or increase within these ranges. The wren is moving up the Okanogan River, and the vireo just began making forays onto the Columbia Plateau. Both of these expansions are predicted.

Likewise, some of California’s oak-dependent species, which would otherwise meet the criteria of resident insectivores (e.g. Oak Titmouse), show little sign of expansion. Oaks are slow-growing trees, which probably limits their ability to move north quickly. Similarly, the Wrentit remains constrained by a barrier it cannot cross—the Columbia River.

Call it the invasion of the Northwest. Call it Californication. Call it climate change or global warming. Regardless, the birds of California are moving north, as predicted and, in some cases, more dramatically than predicted.

ANHU CBC graph.jpg

California’s plan for net-zero by 2045 and net-negative after that

Getting to Neutral cover.jpgIn January 2020, Lawrence Livermore Laboratory released their detailed report Getting to Neutral: Options for Negative Carbon Emissions in California. It provides a detailed plan, with estimated costs, to reach California’s goal of net-zero by 2045, and net-negative thereafter, thus reducing carbon in the atmosphere and potentially returning it to pre-industrial levels.

The plan’s focus is carbon sequestration. For a plan on carbon emissions reductions, see California’s 2017 Climate Change Scoping Plan.

[Note: “ton” always refers to tons of CO2 equivalent (tCO2e).]

The plan relies on three main pillars:

  1. Natural sequestration thru improved land management (sequesters 25 million tons/yr);
  2. Biomass fuels made from forestry and agricultural waste, and garbage, with capture and storage of CO2 (sequesters 83 million tons/yr) (and also displaces the use of fossil fuels);
  3. Direct air capture of carbon, sucking carbon out of the air with large machines (sequesters 17 million tons/yr).
  • Natural sequestration

Chapter 2 focuses on natural solutions, which are among the cheapest options for sequestering carbon. However, they are also all limited by the number of acres upon which we can apply them. There are only so many acres of forests, wetlands, etc. By far, the largest (and cheapest) option in this category is changes in forest management.

Changes in forest management

The easiest way to increase carbon sequestration is to change to the way forests are managed. Specifically, those changes include increasing harvest rotation length, maintaining stocks at a high level, and increasing productivity by removing diseased or suppressed trees. Negative emissions are based on ongoing sequestration of carbon, which may include the transfer of harvested carbon to durable wood products. These practices would sequester 15.5 million tons/yr at a cost of $0.80/ton.

Other natural solutions

Other natural options, in order of the maximum amount of carbon they can sequester, are reforestation, tidal marsh restoration, freshwater wetland restoration, and grassland restoration. These are smaller players—more limited and more expensive. The habitat restoration options are especially limited in their potential contributions and very expensive per ton of CO2 sequestered (although restoration provides other benefits, of course). Together, these options can sequester another 10 million tons/yr at costs that range from $16.4/ton (for reforestation) to $440/ton (freshwater wetland restoration).

  • Biomass fuels

Analogous to current ethanol production, Chapters 3 and 4 call for turning leaves, branches, almond hulls, and human garbage into biofuels, but then also capturing the CO2 and burying it in old oil fields. A small part of the plan includes sequestering, rather than releasing, the CO2 produced during ethanol production. In terms of sequestration, this is the largest plank of the plan. It envisions a massive shift from fossil fuels to plant-based fuels, complete with new pipelines to transport and bury the CO2. It relies heavily on the Central Valley’s agricultural sector and old oil fields. The plan assumes existing crops and does not consider planting crops purely to create biofuels; thus, it does not displace food production.

Because biofuels would displace fossil fuels, it would also result in massive reductions of carbon emissions. However, that is not the focus of the report; the focus of the report is to sequester carbon.

Here is where the biomass would come from:

Forest biomass

Slag from logging, sawdust from sawmills, cleared shrub and chaparral. This would sequester 24 million tons/yr.

Municipal solid waste (household garbage)

This would sequester 13 million tons/yr.

Ag residue

  1. Almond hulls and shells (41% of total ag residue biomass)
  2. orchard and vineyard clippings (30%)
  3. other above-ground plant parts after harvesting from other crops (29%).

These would sequester 13 million tons/yr.

Other

Landfill and anaerobic digester gas. This would sequester 6 million tons/yr.

CLICK TO ENLARGE

Fig11.jpg

All this biomass would be converted, thru various processes (gasification, combustion, fast pyrolysis, hydrothermal liquefaction, and biogas utilization) into various products: hydrogen, grid electricity, liquid fuels (e.g. “gasoline”), biochar, and renewable natural gas.

The cost depends on the biomass collection, transport, biofuel conversion process, and CO2 transport for sequestration. All of these will vary in order to provide a suite of biofuel energy needs (e.g. electricity, transport fuel, etc.). Overall, this biomass fuel network would sequester 83 million tons/yr at an average cost of about $60/ton (ranging from $29-96/ton).

  • Direct Air Capture

Chapter 5 of the report goes into detail about direct air capture (DAC) technology, machines that would suck carbon out of the air and store it in underground (primarily around oil and gas fields in the Central Valley). The report highlights DAC’s unlimited potential in sequestering carbon, but also its high energy demands (and thus expensive cost). In the end, they focus on two main options:

  1. Natural gas-based plants located near underground storage sites. These would still be net-negative.
  2. Geothermal plants (primarily around the Salton Sea), which would require the captured CO2 to be transported a long distance to underground storage sites.

They reject solar and wind-powered DAC as requiring too much land for the energy needed. They do not explore nuclear-powered DAC, such as fourth generation thorium reactors.

All of Chapter 6 is dedicated to long-term geologic storage. They conclude that oil and gas fields in the Central Valley offer the greatest promise, and that “these areas will be safe and effective storage sites. At depths below 3,000 feet, CO2 converts to a liquid-like form that has about the same density and viscosity as oil.”

Their initial cost estimates for DAC exceed $200/ton, though they assume, with learning, an eventual cost of $190/ton.

The Whole System

Fig60.jpgChapter 7 dives into the logistical details and infrastructure needed to connect the gathered biomass to the biomass fuel plants and the DAC plants to underground storage reservoirs. Among their main conclusions:

  • Transportation is a relatively small portion of total system cost, between $10 and $20/ton of CO2 removed.
  • Preexisting rail would the most efficient way to move collected biomass to biomass fuel plants, though some short spur lines would need to be constructed, depending on plant location.
  • A CO2 pipeline would need to be constructed along existing pipeline corridors in the Central Valley and to the Salton Sea, but not elsewhere.

Chapter 8 explores technology learning curves and cost reductions over time, mostly with respect to DAC.

Chapter 9 explores total system cost under several scenarios. They note there is “considerable flexibility among the technology pathways and scenario options.” Table 40 offers the optimum combination of technologies, sequestering 125 million tons per year (and avoiding another 62 million tons in emissions avoided) for a total of $8.1 billion/year, which is an a total average cost of about $65/ton.

CLICK TO ENLARGE

Fig77.jpg

The Role of State Government

There is a plan for California; will it be implemented?

The report does not go into specific policy initiatives or economic incentives necessary to jump start, implement, or transition to this plan. I will address that in another post. Their only mention of public policy is with regard to the CO2 pipeline, where the report notes: “industry experts have expressed concern about the costs and legal difficulties of obtaining rights-of-way for new pipelines in California. One power company shared that running CO2 pipelines on existing natural gas rights-of-way requires renegotiating with the landowners because CO2 pipelines are higher pressure and thus are not covered by existing agreements.”

Direct Air Capture: How the fight against climate change will be won or lost

Fifteen years from now, when the Great Barrier Reef is a thing of the past, when downtown Atlantic City, Bangkok, Boston, Charleston, Dhaka, Galveston, Honolulu, Jakarta, Lagos, Manhattan, Miami, Mumbai, New Orleans, Newark, Rotterdam, San Francisco, Seattle, Tampa, and Venice relocate, and when Australia and California burn, everyone — from farmers to stock brokers, peasants to politicians– will be asking the same question: Are the machines working?

DAC.jpg

Those machines will be sucking carbon out of the air and burying it deep in the ground or under the sea. We don’t know exactly where they will be, what they will look like, or even how well they will work. All we know is that we need them (Lackner et al 2013).

Reducing our carbon emissions, which humans have proved incapable of, is not enough now. Even reducing to zero emissions tomorrow is insufficient. We are too far gone in the wrong direction. What’s more, like a ship heading for the end of the world where the water falls off the edge, our foot is still on the accelerator. Slowing down is good, but insufficient to avert disaster; we must turn the ship around and head the other way. We need to not just reduce emissions, we need to reduce the amount of CO2 already in the atmosphere. That means negative emissions– sucking carbon out of the air.

Direct Air Capture vs Flue Capture; Sequestration vs Re-Use

Carbon capture from ambient air, also called Direct Air Capture (DAC), is different from conventional carbon capture at factory chimney flues (i.e. point source carbon capture). First, it’s a lot easier to capture carbon from flues because the CO2 is concentrated. Second, typically the goal of flue carbon capture is to minimize CO2 emissions and often to re-use the CO2 in a process that reduces the need for fossil fuels. If it is re-purposed, you’ve reduced CO2 emissions from fossil fuels, but the CO2 is still released into the atmosphere. This is a process to reduce emissions; it is not net-negative.

There are also plans to capture carbon, from the air or from flues, and use it in a variety of other industrial processes, from putting bubbles in soda to (wait for it)… extracting more oil. These plans are merely meant to reduce emissions and also to incentivize the private sector to capture carbon. But it’s not net-negative.

Feasibility

Back to direct air capture. Here’s the catch: we don’t know if we can do it at the scale needed. Fortunately, humans have been much better at finding technological solutions than political ones. There are more than a dozen pilot projects in Iceland, Switzerland, and elsewhere showing it can be done– on a very small scale. There are a host of questions, but the biggest challenge is sucking it out of the air in an efficient and cost-effective way.

Funding

Feasibility aside, there’s the question of how to pay for it. Suppose we wanted to capture and sequester 7 billion metric tons of CO2 annually, which is the IPCC goal by 2050. Currently we emit 43 billion. Early estimates are that it would cost $700 billion/year (at $100/ton) and require an enormous amount of energy, up to a 12% of annual worldwide energy use. But those are early estimates. Technology gets better and cheaper with time. The Center for Negative Carbon Emissions at Arizona State University thinks it can be done for $210 billion/yr (using $30/ton) and require only 1% of worldwide energy use.

For context, worldwide military spending is $1.8 trillion/yr (or $1,800 billion), nearly half of which is by the US. If the armies of the world ever wanted to save a city, let alone a village, they have the money to do it.

Ultimately, governments will have to pay for carbon capture and sequestration. There is no way to incentivize the private sector to bury a product rather than re-use it. In the near term, we can benefit from private sector carbon capture and re-use because, although it is not net-negative, it can incentivize research into DAC technology. And it does reduce emissions.

DAC on a meaningful level requires international coordination and, of course, cost sharing. The two most obvious models would be to apportion cost share based on current or past CO2 emissions.

Each nation will likely be up to its own to develop their own funding mechanism. A carbon tax is an obvious solution. If DAC costs $100/ton, that translates to 88 cents/gallon at the pump. Other fossil fuel uses would also have to be taxed as well. While this sounds affordable, there are two complicating factors: 1) we can’t just address the gallons of gas we are buying now; we have to address all the gas we have ever bought and all our parents have ever bought; and 2) carbon taxes are regressive, hitting the poor more than the rich (as a percentage of their income). There are ways around that, a subject for another blog post.

The enormity of the task means that technological innovations to lower the cost are critical. This should not be left to small policy initiatives like research grants and tax incentives. This requires the full weight of all the major governments and universities in the world. Progressive governments in Europe and California (where Democrats have super-majorities in both houses of the legislature) could and should embark on DAC projects immediately.

The Free Rider and Moral Hazard Problems

CO2 released anywhere in the world spreads everywhere, and DAC done anywhere reduces CO2 everywhere. This is both good and bad. It means that DAC can be done anywhere, allowing us to select the most expedient locations. For example, a DAC pilot study in Iceland uses clean geothermal energy to capture carbon and inject it into porous volcanic rocks.

But it also means there’s a potential free rider problem, where countries will shirk their obligations in the hopes that others will take care of it for them. One can imagine rogue nations that refuse to pay their fair share and free ride on the public service provided by other countries. The US, whose share would be large by any measure, is a candidate for such recalcitrant behavior. Public support for DAC could overcome this.

It is possible that Republicans would support DAC. The US Congress recently passed a $50/ton tax credit for DAC removal, the most ambitious such incentive in the world. Republican support, however, probably came from the associated $35/ton tax credit for carbon captured from the air and used for enhanced oil extraction. Regardless, Republicans could see DAC as an opportunity to extend fossil fuel use into the future. And therein lies the moral hazard problem. If we’re doing DAC, one could argue that we don’t need to reduce emissions as much. And if DAC became cheap and easy, fossil fuel use (aside from the spill risks and air quality impacts) could arguably continue.

But, like with a penny saved rather than earned, carbon not emitted is carbon you don’t have to capture and sequester. There are two more reasons why reducing emissions must still happen: 1) at the moment, it’s still cheaper to reduce CO2 emissions than to capture it; and 2) we are nearing the edge of the world, when it’s too late even to capture carbon.

Positive Feedback Loops

This brings us to the gremlins in the room– positive feedback loops. These are additional sources of global warming that are caused by the current global warming. They are force multipliers, accelerators, that can make global warming much worse very fast. It’s hard to predict when they will kick in. If they do, our job will become much much harder. We will lose ground, a lot more ground (read human suffering) before we win. They put victory in doubt.

Some positive feedback loops, such as increased water vapor in the air and dark seas and mountains exposed from melting ice and glaciers, have been accounted for in climate models. More pernicious are the more unpredictable “time bombs”, such as permafrost melt and massive wildfires.

Melting permafrost is the proverbial elephant of the gremlins in the room. Research suggests that rapid methane releases from melting permafrost may have been the final driver in runaway climate change that led to past mass extinction events, including the End-Permian Extinction in which 97% of all life on earth perished. This effect is already happening. NOAA recently reported that melting permafrost now contributes as much as net 0.6 billion tons of carbon (equivalent to 2.2 billion tons of CO2) to the atmosphere each year; “the feedback to accelerating climate change may already be underway.”

Forests are normally carbon sinks, taking in CO2. However, in 2006 Westerling et al warned that “forests of the western United States may become a source of increased atmospheric carbon dioxide rather than a sink, even under a relatively modest temperature-increase scenario.” Since then, wildfires have increased dramatically.

These positive feedback loops are like an increasing current threatening to pull the ship over the falls. If we are waiting for technology to save us, we may have waited too long.

Controlling the Climate

In the long run, Homo sapiens might eventually hopefully maybe win the climate battle and be able to capture and sequester enough carbon to return the earth’s atmosphere to normal conditions. But there will be suffering in the short-term, for the next two hundred years, thru sea level rise, heat waves, droughts, powerful hurricanes, and agricultural disruption. The poor will suffer most. Turning the climate around is like turning a cruise ship. There’s a lot of lag time between cause and effect. That’s why humans have found themselves in the current crisis. Only the scientists saw it coming. Nobody felt the impacts until now, and now it’s too late to avoid them. The same is true regarding corrective measures. A lot of sea level rise, caused by ice melt in Greenland and Antarctica, is already built into the system. It is coming and coming at an increasing and exponential rate. We may have to actually cool the planet beyond the recent historic level to stop it. And that may take 150 years. In the meantime, hundreds of coastal cities will go under water. This appears inevitable, even under the most optimistic scenarios.

The graphs below present the most wildly optimistic scenario, achieving the Paris goal’s peak emission in 2020 (this year), DAC of 7 billion tons of CO2 per year by 2050, plus optimistic net removal thru reforestation and new soil management practices, all of which help to get us to net-zero emissions by 2050, another Paris goal. After that, we remove more than we emit; we are net-negative, returning the earth to under 400 ppm.

It would be great to just use natural approaches to sequester carbon (e.g. reforestation and soil management). But the numbers just don’t add up fast enough. During past global warming events (e.g. the Paleocene Eocene Thermal Maximum), it took the earth’s natural processes tens of thousands of years to restore balance. We have put so much carbon up so fast thru industrial processes that we need the same kind of speed sucking it back in. Nevertheless, looking at the graph below, reduced carbon emissions are still the biggest player, followed by DAC and the natural processes. We need it all to the maximum extent possible as soon as possible.

But this wildly optimistic scenario still has us peaking at 510 ppm in 2050, high enough to hit 2.0 Celsius warming, which is perilously close to unleashing enough carbon and methane from permafrost and other positive feedback loops to launch us toward 3 or 4 or 5 C warming and create another mass extinction event  (which we know from the past the world will recover from, re-evolving new life forms, in a few million years).

DAC chart1.jpg

The graph of CO2 levels below is derived from the assumptions regarding CO2 emissions and removal above. This is a best case scenario.

DAC chart2.jpg

But suppose humanity gets past this. Successful implementation of carbon capture and sequestration would mean that Homo sapiens can control the earth’s climate. That brings with it a host of other questions. At what level do we set atmospheric CO2? Do we return to 300 ppm or lower? Who decides? Because carbon released or captured anywhere affects everywhere, who will police it? These are questions for our children, if they are fortunate.