- Author: Kat Kerlin
Reposted from UC Davis News
As climate change transforms California's landscape in the years to come, coastal habitats appear to be more resilient than many other places in the state. (Getty Images)
Current levels of greenhouse gas emissions are putting nearly half of California's natural vegetation at risk from climate stress, with transformative implications for the state's landscape and the people and animals that depend on it, according to a study led by the University of California, Davis. However, cutting emissions so that global temperatures increase by no more than 2 degrees Celsius (3.2 degrees Fahrenheit) could reduce those impacts by half, with about a quarter of the state's natural vegetation affected.
The study, published in the journal Ecosphere, asks: What are the implications for the state's vegetation under a business-as-usual emissions strategy, where temperatures increase up to 4.5 degrees Celsius by 2100, compared to meeting targets outlined in the Paris climate agreement that limit warming to 2 degrees Celsius?
“At current rates of emissions, about 45-56 percent of all the natural vegetation in the state is at risk, or from 61,190 to 75,866 square miles,” said lead author James Thorne, a research scientist with the Department of Environmental Science and Policy at UC Davis. “If we reduce the rate to Paris accord targets, those numbers are lowered to between 21 and 28 percent of the lands at climatic risk.”
The report notes that this is a conservative estimate because it only examines direct climate exposure. It does not include increased wildfire or insect attacks on forests, which are also intensifying and likely to increase with further warming. These secondary effects are likely to have large impacts, as well, the authors say. For example, during the recent drought, more than 127 million trees died primarily due to beetle outbreaks, and wildfires have consumed extensive amounts of natural vegetation.
68 percent of LA, San Diego regions impacted
The study features maps of the state and shows the climate risk to 30 different vegetation types under different climate scenarios. It projects that at current rates of greenhouse gas emissions, vegetation in southwestern California, the Central Valley and Sierra Nevada mountains becomes more than 50 percent impacted by 2100, including 68 percent of the lands surrounding Los Angeles and San Diego.
“This is the map of where we live,” Thorne said. “The natural landscapes that make up California provide the water, clean air and other natural benefits for all the people who live here. They provide the sanctuary for California's high biodiversity that is globally ranked. This map portrays the level of climate risk to all of those things. In some cases, the transformation may be quite dramatic and visible, as is the case with wildfire and beetle outbreaks. In other cases, it might not be dramatically visible but will have impacts, nevertheless.”
Resilient areas also identified
The study and its maps are being used by state agencies and land managers to make decisions under changing conditions. Commissioned by the California Department of Fish and Wildlife, the data is helping the agency understand not only which parts of the state are vulnerable to climate change, but also which areas are more resilient, such as some coastal areas and parts of northwestern California, so they can ensure they remain resilient.
“In California, we have good information on the vulnerability of fish and wildlife to climate change,” said Whitney Albright, a project manager with the California Department of Fish and Wildlife. “But we were missing this crucial piece of climate risks to underlying habitat. This study helped fill the information gap. We've already started to use its data in our conservation planning efforts.”
The study also provides a risk assessment for policymakers to consider the benefits to California of reaching Paris climate agreement emission targets that limit global warming to 2 degrees Celsius, and the risks to the state of remaining on the current business-as-usual level of emissions and temperature warming.
Co-authoring institutions included the California Department of Fish and Wildlife, Sequoia and Kings Canyon National Parks, and the U.S. Geological Survey.
The study was funded by the U.S. National Park Service and the California Department of Fish and Wildlife./h2>/h2>/figcaption>
- Author: Glen Martin
Reposted from California Magazine
Back when mastodons and giant ground sloths still roamed the earth – the late 70s and early 80s – I worked as a wildfire fighter for the U.S. Forest Service, both on hand crews and engine crews. Our training was narrow but relatively deep. Mainly, we were taught to construct fire lines with hand tools and chain saws. Water, when it was available, generally was used to protect the line and firefighters; seldom was it employed to directly extinguish the flames.
Our basic strategy consisted of digging and cutting line around the flanks of the fire, then burning out fuels to the advancing flames with fusees (devices resembling highway flares) or drip torches. In this way, the “head” of the fire could be steered to natural barriers or areas sufficiently devoid of fuels to make a direct attack possible. We received zero training for structure firefighting. The one time I responded to a burning structure was in Trinity County: A vacation cabin was ablaze due to a faulty propane line. Several engines responded. Federal Forest Service engines are smaller and hold far less water than municipal or state engines, but collectively, we mustered a lot of water on the scene. A direct attack could have been possible, but we knew our training for battling such a fire was inadequate. Instead, we dug a line around the cabin so the flames wouldn't encroach into the surrounding woods, and watched it burn to the ground.
Things are different now. For one thing, wildfires are bigger and more frequent. This is due to drought, climate change, and the sins of past forest managers. In the sixties, seventies and eighties, vast tracts of old growth timber were liquidated in massive clear cuts. These deforested landscapes were replanted as conifer monocrops, resulting in expansive stands of spindly, closely-spaced, second-growth trees that are as flammable as kerosene.
Meanwhile, the goal for wildfire fighters has changed drastically. The emphasis now is on “protecting interface,” which means preventing fires from immolating the homes that have sprouted across the West's woodlands like morel mushrooms after a rain (back when we had rain). This shift has made fighting wildfires far more expensive, more dangerous for firefighters, and has altered priorities from protecting public forests to protecting private assets. Wildfire fighters now receive training in structure fires, but that has diluted, perhaps even vitiated, their original mission. As Berkeley Environmental Science Professor and Wildfire Researcher Scott Stephens noted, more than half the U.S. Forest Service budget for the current fiscal year is dedicated to fire suppression; in the early 1990s, that figure was about 20 percent. Assuming the trend will continue, which seems certain, firefighting could consume 70 percent of the agency's budget by the 2020s.
That means there's less money than ever for restorative work. And this is work that must be done, and soon. Unless we alter the essential characteristics of our coniferous forests, they will quite literally vanish. It's already happening: Stephens observes that significant portions of California's forests are shifting from pine and fir to mixed hardwoods or even grasslands, the result of repeated, high-intensity fires and drought. And once our conifers are gone, we're not getting them back. The change will be permanent.
Even with drought and accelerating climate change, we can still have healthy coniferous forests in the West. But we won't get them by simply letting them grow — and burn (and burn). Stephens observes we need active management: intensive thinning by both mechanical means and prescriptive fire. This will result in forests with fewer but healthier trees, forests that are largely resistant to any but the most catastrophic fires.
A hundred years ago, disastrous wildfires were rare in California. Forests were characterized by widely spaced, extremely large trees; You could ride through them on horseback, unimpeded. Any fires that did ignite generally crept along. They didn't have the “fuel ladders” — dead limbs and needles on the ground, brush and ascending foliage higher up — needed to climb into the crowns of the trees and explode into rolling fireballs. Being large, the trees were thick-barked and resistant to fire. Indeed, periodic low-level fires disposed of deadwood, killed destructive insects, and returned nutrients to the soil as ashes. It was a virtuous cycle, assuring healthy, resilient wild lands that depended on fires, but were not destroyed by them.
That changed with the aggressive fire suppression of the Smokey the Bear era and accelerated clear-cut logging. But as Stephens notes, we can revitalize the “dog hair” (as in, thick as the hair on a dog's back) forests we now have. We can re-create the vibrant, fire-resistant forests of the early 20th century. We know how to do it. We have the tools: chain saws, heavy equipment, and prescriptive fire. It's not that complicated.
But it will take political will and money. It won't require a Manhattan Project-style response —but it'll require one similar to the Civilian Conservation Corps in scope and commitment. We need to put young men and women back into the woods in force, cutting trees and conducting controlled burns. By re-introducing fire into forest ecosystems, we can, paradoxically, protect them from fire. This will entail triage. We'll have to identify those areas that are most vulnerable to fire (e.g., interface communities). The first projects should be shaded fuel breaks, strips of thinned forests around highways and rural towns and residential developments. Following that, more ambitious projects could proceed on larger tracts.
Who pays? The state and feds must contribute, of course. But local communities, commercial timber companies, and private landowners must also cough up. In particular, the counties and interface residents must participate. So far, they've gotten a free ride. County planners have encouraged development in wild-land areas without thought to the implications of wildfire; After all, taxpayers have always picked up fire suppression costs. More suppression costs must be passed on to the counties so they are incentivized to discourage development in our wild lands, and homeowners must pay appropriately heavy premiums if they choose to build in the woods.
Stephens estimates we have about 30 years before it's too — before our coniferous forests are gone forever, replaced with oak woodlands, brush fields, or grassy savannas. And even then, of course, the wildfires will continue. As we saw with the recent Middletown conflagration, hardwood forests and scrublands can burn just as ferociously as conifers. As long as homes intrude into the wild lands, their continued destruction is assured.
We can continue down the current path of increasing fires and escalating suppression costs, or we can invest in forest restoration. The first course is a death spiral. The second will reduce wildfires, preserve the essential character of our wild lands, provide tens of thousands of jobs to young Americans, yield economic benefits ranging from timber production to recreation, stabilize watersheds, and preserve wildlife diversity. Let's just hope we do the right thing.