Last week, I put together this short news video with Nate Lewis about the proposed carbon tax for South Africa. You can see the original at IPS news.
Last week, I put together this short news video with Nate Lewis about the proposed carbon tax for South Africa. You can see the original at IPS news.
Image: first of a three-part infographic about how California’s cap and trade program works. Designed by Andy Cullen and copyright High Country News.
This year, California rolled out an economy-wide carbon cap and trade program, the first of its kind in the U.S. There is a lot riding on the success or failure of this program, not least because California is the ninth largest economy in the world and is going it alone with cap and trade in the U.S. The Golden State also has a legacy of introducing pioneering environmental legislation that other states and eventually the federal government adopt.
In my latest story for High Country News, I write about how the state has designed the program to avoid the mistakes of the European Union’s carbon trading scheme, which has suffered from overallocation of carbon credits and subsequent slumps in the carbon price.
The story also highlights the concerns of a major steel producer, California Steel Industries, which, like other businesses, is concerned about finding cost-effective ways to reduce its carbon emissions as the carbon “cap” tightens in future.
Here’s an excerpt:
The Golden State forged ahead with the carbon dioxide cap-and-trade program despite the U.S. Senate’s 2010 failure to pass a national program. Given the state’s history of implementing environmental regulations that later become national policy, a successful cap-and-trade system could serve as a federal model. If cap-and-trade in California “fails, or is perceived to have failed, then that could be the nail in the coffin for cap-and-trade consideration as a policy instrument in Washington,” says Robert Stavins, a Harvard professor who studies climate policy.
While its overall impact on U.S. emissions won’t be major, the California experiment makes several improvements to existing cap-and-trade strategies. It covers more sources of pollution than the five-year-old Regional Greenhouse Gas Initiative in the Northeastern U.S., which applies only to power plants. The European Union started the world’s largest carbon cap-and-trade program in 2005, but it had a significant flaw: the initial stage of the program gave away too many free credits, resulting in some power companies raking in windfall profits by raising electricity prices even though they didn’t have to pay for their allowances. It also contributed to low prices for carbon allowances, which provides scant incentive to cut emissions.
Mary Nichols, head of the California Air Resources Board, the agency steering the state program, is confident that California’s effort will be different. The program covers 360 businesses, which represent about 600 facilities that each release more than 25,000 metric tons yearly — enough to put a big dent in California’s total carbon output. The EU’s difficulty, Nichols notes, was that authorities didn’t have an accurate measure of the total quantity of emissions initially. California, though, has had a greenhouse-gas reporting requirement in place since 2008.
Full article at High Country News.
Image: Willow2012 via Wikimedia Commons under Creative Commons License
Scientists predict a daunting set of potential consequences of climate change. With the possibility of increased droughts, a higher frequency of wildfires, rising sea levels, the decimation of deep ocean sea creatures, and threats to global food security, the future of a warmer world appears bleak.
What if the unpredictable effects of climate change arrive quicker than expected? Advocates of geoengineering, which involves manipulating the Earth’s climate with technological mechanisms, some of which, like blasting large mirrors into space to reflect sunlight, come straight from the annals of science fiction, argue that geoengineering could offer a last resort fix to save the planet. It could be used as a form of “insurance,” as Graeme Pearman of Monash University has put it. Critics, however, worry that if climate quick fixes are on hand there will be little reason for nations to cut their carbon emissions and reduce the level of carbon dioxide in the atmosphere.
Image: A wildfire in southern Montana, August 2007, captured from space by astronauts docked to the International Space Station. Credit: NASA Johnson Space Center via Flicker – NASA Goddard Photo and Video.
In March I ran a post about a NASA wildfire model that predicts increased fire activity in the Western U.S., along with other parts of the world, in future as a result of rising global temperatures. This feature (published at New West) expands on the earlier post, with insights from NASA scientist Olga Pechony (who built the NASA model with colleague Drew Shindell) and Anthony Westerling, an expert on wildfires in the West, based at the University of California’s Sierra Nevada Research Institute. Continue reading
Photo courtesy Joe Giersch, USGS Northern Rocky Mountain Science Center.
[Article published at NewWest.net, April 19, 2011].
Montana’s Glacier National Park is expected to look quite different in 20 years time. Scientists predict that that the park’s remaining 25 glaciers will disappear by 2030, their icy faces having melted as a result of global warming.
Along with the depletion of the sanctum’s permanent snowfields, the destruction of the glaciers is predicted to take its toll on a lesser-known insect, the meltwater lednian stonefly, which researchers have observed in just 11 of the park’s frigid alpine streams.
The Waterton–Glacier International Peace Park, which incorporates Canada’s Waterton Lakes National Park and Glacier National Park, is the only place where scientists have documented the rare bug. A handful of Glacier National Park’s frosty waters, fed by crisp glacial and snow run-off in the summer time, are well suited to the stonefly’s requirements, since it inhabits streams with average summer water temperatures of less than 50 degrees.
In a recent study, scientists from the U.S. Geological Survey predict the stonefly will lose more than 80 percent of its habitat due to melting glaciers and reduced snowpack in the park, which could ultimately result in its extinction. And while the tribulations of this obscure invertebrate might not seem of dire importance, the stonefly’s plight speaks of challenges facing other vulnerable alpine insects.
A community of unsung insects lives in Glacier National Park’s waters. Some species of caddis fly are only found there and in the Canadian Rockies, while another rare insect – a type of amphipod, which is a little crustacean – has only been found at six locations in the park and nowhere else in the world, said Joe Giersch, an aquatic entomologist at the U.S. Geological Survey and co-author of the study.
Since the late ‘90s, Giersch has been trekking the park, scouting isolated alpine streams and springs for these insects. He is particularly proud of one caddis fly specimen, which he found only once and had not been seen since the ‘50s.
“The real take-home message is that we really aren’t just dealing with one single species here. We’re dealing with a whole ecosystem of interest: a very rare ecosystem that is dependent on very cold and permanent water,” said Giersch over the phone from his office at the Northern Rocky Mountain Science Center in Montana.
Once streams fed by snowmelt and glacial melt have dried up or become intermittent, the “last refuge” for the insects would be streams fed by underground springs, he explained.
As the alpine streams the stonefly calls home continue to dwindle, it’s likely stonefly populations will become more and more isolated, since the insect is not very mobile, he said.
“They’re not very efficient fliers, so we don’t think they can travel very far and re-colonize different streams,” he said.
Stonefly Number 260 to Hit Endangered Species Waiting List
On April 4, the U.S. Fish and Wildlife Service announced that because of the meltwater lednian stonefly’s impending predicament – a loss of its natural habitat due to the glaciers melting – the insect warrants protection under theEndangered Species Act. But, since other priority plants and animals need to be addressed, the stonefly will join 259 other species on a list of candidates for federal protection. The candidate species receive no statutory protection while on the waiting list. However, the Fish and Wildlife Service does provide grantsto states and territories which have entered into a cooperative agreement with the agency to initiate voluntary conservation programs for candidate species on non-federal lands.
Species on the candidate list receive a listing priority number, ranging from 1, highest priority, to 12, lowest priority. The number is given because “there are not enough Service personnel, time, or money to propose all the candidate species for listing,” according to a Fish and Wildlife Service document.
The Fish and Wildlife Service awarded the stonefly a priority number of 4. This does not guarantee a date when the stonefly will graduate to official endangered or threatened species status, since the Service has to process higher priority candidates before dealing with the lowly stonefly.
Some plants and animals have been on the waiting list for over 20 years, explained Tierra Curry, a conservation biologist with the Center for Biological Diversity, a non-profit environmental organization working to protect native species and their habitats.
Twenty-four species have gone extinct or missing – defined by the Center’s researchers as “not having been recorded in 10 years despite survey efforts,” while idling on the candidate list, according to a Center for Biological Diversityreport. One such species is the shortnose cisco, a salmon not seen since 1985 in the three Great Lakes – Michigan, Ontario, and Huron – it used to inhabit, chiefly due to overfishing.
Curry criticized the Obama administration for not doing enough to protect imperiled species.
“Obama’s endangered species record is terrible. He’s dragging his feet,” she said. “It’s extremely disappointing to those of us who were hoping for hope and change, because he hasn’t improved the Fish and Wildlife Service very much over the second Bush administration.”
“He’s done better than George W. Bush, but that’s no record to be proud of,” she said. “George W. Bush didn’t put a single species on the Endangered Species list that wasn’t court ordered.”
The Center for Biological Diversity has monitored government efforts to award endangered species protection dating back to 1974. The Obama government has given Endangered Species Act protection to 58 species so far. By contrast, President Clinton, somewhat of a champion of preservation, awarded federal protection to about 65 species per year, for a total of 522 protected species. George W. Bush listed 62 species during his two terms in office.
Stonefly Not Left Stranded
The status of candidate species is reviewed each year. While the stonefly waits in line, biologists from the Fish and Wildlife Service will be working with the USGS and academic scientists to get a better understanding of the stonefly’s dispersion, genetics, lifecycle and habitat needs, said Beth Dickerson, a Fish and Wildlife Service wildlife biologist, based at the Montana Field Office, who is responsible for updating the stonefly’s record each year.
It’s possible the stonefly might be found in other places in the Rocky Mountain area, she said.
“I would imagine it is going to show up, at least a little bit farther north and a little bit farther south,” said Giersch.
The scientists will be running experiments to identify the lethal limits of the temperatures the stonefly can survive. They will also be trying to figure out what the insects eat. Along with genetic research, this will provide a better idea of the stonefly’s ability to survive in the face of climate warming, Giersch explained.
Stonefly Not Alone in Facing Climate Change
The Fish and Wildlife Service has identified climate change as the primary threat to the stonefly’s continued existence. But other candidate species in the Rocky Mountain West may also be affected by climate warming. The 2010Candidate Notice of Review, a Fish and Wildlife Service report providing updated information about all candidate species, mentions climate change as a potential threat to 19 candidate species. Nine of these species, including the Rio Grande Cutthroat trout – native to Colorado and New Mexico and found in the drainages of the Rio Grande, Pecos and Canadian rivers – reside in the Rocky Mountain West.
“Climate change is the number one future threat to biodiversity,” said Kassie Siegel, director of the Center for Biological Diversity’s Climate Law Institute, over the phone from Los Angeles, where she was attending a conference on the Clean Air Act at the University of California, Los Angeles. “In the past it was habitat loss and introduced species, but climate change is going to overtake those – it’s the largest threat we’ve ever faced.”
Image: An August 2000 wildfire in Bitterroot National Forest, Montana. Credit: Alaska Forest Service/John McColgan
Wildfires are already a common occurrence in the Rocky Mountain West. And if NASA scientists are correct, a warming climate will only ramp up the frequency of wildfires in future.
Over the past 30 years, warmer and drier conditions in the Rocky Mountain West have made vegetation more flammable, which has led to an increase in wildfires, said Peter Hildebrand, director of the earth sciences directorate at NASA’s Goddard Space Flight Center, speaking at the Conference on World Affairs at the University of Colorado this week.
A new NASA wildfire model shows that these increasing fire trends are set to continue with a warming climate, Hildebrand said during the panel in Boulder.
As the earth heats up, global circulation patterns are changing and the winter storm track is being pushed further north. This results in less precipitation, higher temperatures and more evaporation in the Rocky Mountain West, Hildebrand explained.
NASA scientists project that with the effects of climate change, the frequency of fires in the West could increase between 30 and 60 percent by 2100. At the same time, the wetter Eastern part of the country is expected to experience decreased fire rates in the future.
“I want you to think a little bit of fire as a metaphor for the many things that climate change holds for us,” said Hildebrand.
In terms of adapting to increased fire activity, it’s important for people living in fire-prone areas to think about home construction, the vegetation around their homes and the location of homes, he said.
To build their wildfire model, the scientists used satellite measurements of vegetation density, temperature, precipitation, lightning and fire activity over recent decades and plugged them into a computer model to estimate climate and fire conditions dating back to the year 850. They combined these estimates with land-use and population reconstructions. The scientists compared this computer modeled data to charcoal layers harvested from lake core sediments around the world, dating back 2,000 years, and found a good correlation between the data.
At the same time, in a 2010 paper the scientists note that the model is not perfect because “highly incomplete” information on fire-related human activities makes it difficult to gauge the role humans played, globally, in igniting and suppressing fires, especially during the Industrial Period.
The wildfire model identifies three key eras in global fire history. Before the industrial era, precipitation levels largely dictated fire levels around the world, according to the scientists.
“By and large humans were not very much affecting climate before the industrial revolution,” said Hildebrand.
From the industrial age onward, rapid population growth led to an increase in human-caused fire and by 1900 the number of fires around the world had increased to about 20 percent higher than pre-industrial levels, said Hildebrand.
After 1900 there was a significant reduction in wildfire because of improved firefighting technologies, he said.
And while humans have been responsible for starting the majority of fires over the past century, and for successfully putting them out, by 2050 the model predicts that warmer temperatures will play a key role in dictating fire activity around the world.
“These results suggest a possibility that in the future climate will play a considerably stronger role in driving global fire trends, outweighing direct human influence on fire (both ignition and suppression), a reversal from the situation during the last two centuries,” the scientists write.
“Our projections show that our rising temperatures — this time driven by humans — are on the verge of reasserting control over the world’s fires,” said study author Olga Pechony in a NASA news report.
Today, NewWest ran a story I wrote on a report from the Stockholm Environment Institute, which suggests that farmers could cut back on crops that don’t fetch enough value for the amount of water used to grow them as one way to help curb the growing demands for water in the Southwestern U.S.
Economists Frank Ackerman and Elizabeth Stanton, the authors of the report, ranked Southwestern crops based on their dollar value per acre-foot of water used to grow them. (An acre-foot of water is considered enough to meet the needs of two four-person families for a year).
[from the NewWest article verbatim]
Nursery and greenhouse products came out on top, earning $28,000 per acre-foot. Vegetables, fruits and nuts generally brought in sales above $1,000 per acre-foot.
Dairy and cattle (with water for hay to feed them factored in) came in at $900 per acre-foot. However, there was a huge discrepancy between California, where dairy and cattle earn more than $1,200 per acre-foot, and Utah, where they earn less than $250 per acre-foot.
Cotton, wheat, corn, rice and other grains scored low, with values of under $500 per acre-foot.
Hay is somewhat of an outlier, since across the Southwest it fetches the lowest value per acre-foot of water used – $121 on average. But, as the researchers emphasize, it’s important since it’s grown chiefly to feed cattle and dairy animals.
Using data from the National Agricultural Statistics Service, Ackerman and Stanton calculate that hay saps 42 percent of the Southwest’s agricultural water, while dairy and cattle account for 31 percent of total agricultural sales in the region. This relationship differs by state.
In Utah 94 percent of agricultural water goes to hay growing, but cattle and dairy sales only bring in 45 percent of the state’s total agricultural sales.
In New Mexico the ratio is more evenly weighted. Seventy-six percent of the state’s agricultural water is funneled to hay growing, while dairy and cattle account for 74 percent of total agricultural sales.
“Hay is more complicated than the other crops. We’re not making any direct recommendation there,” said Stanton in a telephone interview.
However, Stanton said hay is usually not transported over long distances and tends to be sold through local markets, but looking at selling it more widely is something that could be considered. She also explained that there is room for research into more efficient uses of water in hay farming.
“This is an area where so much water is used in such dry areas that it seems like a priority area for government extension services and universities to get involved and say, ‘How can we grow this hay with less water?’” she said.
According to Ackerman and Stanton, “in most Southwest states, farming cotton, grains, oilseeds and dry beans and peas brings in less value per acre-foot of water than would the sale of the water itself.” In theory, this means some farmers would be better off selling water instead of using it to grow their crops, although in reality they seldom have the rights to do so.
While the cost of water varies for different users in different states, according to water rights, allocations and subsidies, the authors highlight that some municipalities pay $2,000 or even $3,000 per acre-foot to supply water to homes and businesses. In Utah utilities have paid up to almost $5,200 per acre-foot, according to the report.
The report also shows how different states exert different demands on water supplies. Utah, for instance, “uses more domestic water per capita than any state but Nevada per day.” New Mexico uses the least domestic water per capita in the Southwest, which means it ranks 16th in the country for domestic water usage. At the same time, New Mexico uses close to 90 percent of its water supply on agriculture.
The researchers suggest that “eliminating the lowest value-per-unit-water crops (excluding hay) would lower agricultural water use by 24 percent, while reducing farm sales by less than 5 percent.”
“We can’t say anything about the particular circumstances of particular farms, but the suggestion would be to switch from a lower value crop to a higher value crop,” said Stanton. “And these aren’t just crops that are lower value in terms of per-acre foot [of water used]. These are also lower value crops in general.”
In strictly financial terms, Ackerman and Stanton calculate that by 2050 increasing water shortages will cost the Southwest between $7 billion and $15 billion – about 0.3 to 0.6 percent of the region’s GDP for 2009. By 2100 projected costs hit between $9 billion and $23 billion.
“Adaptation,” they write, is “a bargain that the region cannot afford to ignore.”
Please visit NewWest.net for the full article.
In journalism school we tend to spend a lot of time discussing the best way to communicate climate and environmental issues. I hadn’t thought much about singing about it until Andrew Revkin mentioned the “singing geologist” Richard B. Alley at a talk I attended today. Alley is a professor of Geosciences at Pennsylvania State University. He is a recipient of the Seligman Crystal, an award from the international glaciological society, for his contribution to the understanding of the stability of ice sheets and glaciers in Antarctica and Greenland, and of erosion and sedimentation by this moving ice.
With guitar in hand he has created a set of music videos – “the Rock Videos.”
Here’s his take on Creedence Clearwater Revival’s “Rolling on a River.”
Here’s one for the seismologists, from a man in black.
I dig this guy’s style.
By the turn of the century Miami will be underwater. That is the sobering news from James White, director of the Institute of Arctic and Alpine Research.
“The sea level that’s rising now is a slow freight train that’s already moving,” said White, speaking to my science writing class at his laboratory on October 18. “It won’t stop at the year 2100. It will keep rising. This means big trouble for cities like Miami, Norfolk and Philadelphia.”
White’s bleak predictions are based on climate models and data sourced from ice cores drilled deep below the ice sheet in Greenland and the Antarctic. Recently, White has been working alongside scientists from 14 countries at the North Greenland Eemian Ice Drilling project. The team began drilling in June 2009. This August they hit bedrock, some 8,300 feet beneath Greenland’s frigid surface.
The multiple layers of the Greenland ice sheet hold valuable information about atmospheric conditions, including air temperatures, moisture levels, and the concentrations of greenhouse gasses, dating back hundreds of thousands of years. The deepest layers of ice were formed throughout the Eemian period, which occurred during the last ice age. Spanning from 130,000 to 115,000 years ago, the Eemian was what scientists call an interglacial period: a transitory interval of warmer global temperatures between cold periods of rapid glacial production.
The Eemian was the last time the Earth’s average temperature was as warm as it is now. It was six degrees Celsius warmer in the Arctic and sea level was three to five meters higher than we know it, White said.
This makes the Eemian a good gauge for predicting how rapidly sea level will rise in line with present and predicted warming conditions, which are the result of increased greenhouse gas concentrations in the atmosphere due to human activities, White explained.
White and his colleagues use data from the Eemian ice core to analyze how much of the Eemian sea level rise was a result of parts of Greenland melting. Similar research is done in Antarctica to measure how the melting of the Antarctic ice sheet contributed to sea level rise. This information should provide insights into how rapidly these regions will melt under warmer conditions in the coming decades, White said.
White pointed out that sea level rise will severely damage infrastructure at coastal cities. “With a three feet rise Miami’s airport is under water. Imagine sewer systems don’t work anymore. Any buried electrical lines are in trouble; roadways are in trouble,” he said.
White believes that careful and informed decisions regarding city engineering need to be made at the political level. “The question is how far do you go inland before rebuilding again?” he said.
White affirmed that humans will not destroy the planet because Earth has experienced higher concentrations of atmospheric carbon dioxide and extreme temperatures in the past. But we will drive other species to extinction and create challenges for our own survival, he said.
“We’ve predicated modern societies on our climate. There are abundant examples from the past where societies collapsed because of climate change,” he cautioned.
“One generation passes its problems onto another. We had every bit of intelligence to deal with this problem in the 1950s. We ignored it then. What I find astounding is that we ignore it now.”
Image: NEEM ice core drilling project – www.neem.ku.dk
Desert dust blown from the arid regions of the Colorado Plateau and Great Basin contributes to earlier snowmelt in the Upper Colorado River Basin. A recent study indicates that this premature snowmelt reduces the annual flow of the Colorado River by five percent.
Based on hydrological modeling, the study co-authored by Brad Udall and Jeffrey Deems, based at the Western Water Assessment, and Tom Painter, snow hydrologist at NASA’s Jet Propulsion Laboratory, indicates that between 1915 and 2003 snowmelt has occurred on average three weeks earlier on mountains in the Upper Colorado River Basin than it did prior to the arrival of Anglo-Saxon settlers in the 1850s.
Dust accumulated on the snowpack decreases snow’s albedo – its capacity to reflect solar radiation. Because of dust’s dark color it absorbs more sunlight, leading to accelerated melting. This premature snowmelt extends the growing season of plants that under historical conditions would be covered by snow until later in the season. Evapotranspiration, the process whereby water moves from plants and soil into the atmosphere, results in the loss of some 750, 000 acre-foot of water each year. This is sufficient to supply Los Angeles for 18 months.
This yearly deficit has been unwittingly incorporated into the allocation of the Colorado River, which serves 27 million people in seven states and Mexico. The study indicates the river is over allocated by ten percent.
Jeffrey Deems says that even if mitigation measures, such as improved land management practices, curtail the annual water loss it won’t be a “silver bullet.”
The predicted future effects of climate change in the Southwest need to be carefully considered. Also, Deems notes that in 2009 and 2010 there was a particularly high dust load on the snow.
I spoke with Deems to get some insights into the study and the effect of dust on snow. (I’m running this as a QnA).
BB: I’ve read that average temperatures have increased in the Southwest during the twentieth century and the winter storm track is moving northward. Is there any way this warming is contributing to snow melting earlier?
JD: It definitely is doing that. The impacts of climate change and dust can both be characterized as forcing: there’s something extra in the system beyond its average state that’s pushing the response. The dust forcing is currently vastly stronger than the climate forcing.
Climate change impacts have a direct effect on snowmelt and snow accumulation. They also have a direct effect on soil moisture and vegetation in the desert. It’s not so much the direct climate forcing on the snow that’s the issue, but the climate forcing in the desert that has a bigger impact on snowmelt.
BB: This dust comes from the Colorado Plateau and northwest New Mexico, northeast Arizona and southern Utah. Is climate change producing more dust in these regions?
JD: We’re working on that. The easy answer is yes, but I think that’s too easy of an answer. We’re in an extended period of drought in the Southwest. Drought definitely impacts vegetation growth, soil moisture availability, re-growth of crusts on the soil surface, and also invasive plant species.
There are definitely impacts happening out there that are no doubt influenced by climate warming. Now, that will very quickly devolve into a detailed argument. How would the duration and magnitude of the current drought be changed if we were still at pre-industrial levels? That’s a very difficult question to answer.
All we can really say is that there are impacts of climate change being felt in the dust emission regions that are likely contributing to enhanced emissions, but we don’t know that. What is worrisome is the potential for further impacts of climate change on the vegetation and land condition in the desert, which could dramatically enhance dust emissions.
In 2009 and 2010 we’ve seen quite a lot of dust on the snowpack. The current conditions scenario in our modeling study closely matched conditions we observed in 2003 to 2008. They did not represent the severe dust loading of the past two years. Our current work is to replicate the same study with an enhanced dust scenario that matches 2009 and 2010.
If you look at 2008 and 2009, we had the same amount of dust events after March 1, but 2009 had over four times the dust concentration in the snowpack. In 2008 snow melted out about 25 days earlier than it would have in a pristine snowpack. In 2009 we were on the order of 50 days.
There’s something about the land conditions out in the source regions that allowed the same number of storms to deposit a lot more dust. Maybe the storms were more intense. There’s a whole chain of processes involved, from dust being available for transport, to getting picked up, carried and deposited in different locations, and then affecting snowmelt.
BB: The study indicates that in 1920 dust loading was six times that of pre-1850 conditions. Since then it has averaged a fivefold increase on these condition. Is it possible that there could be a future event where it exceeds the sixfold level of dust?
JD: Yes. You know, I haven’t actually done any math on it, but it’s likely the last two years have greatly exceeded that. That sixfold increase comes from Jason Neff’s work. He and his team took lake sediment cores in some alpine lakes in the San Juans. The sediment accumulation rate in the lakes is a good barometer of dust deposition. Not to a time resolution of an individual year, though, but it’s relatively high, kind of sub-decadal.
Round about the mid 1800s we see a dramatic jump – 600 percent jump in dust accumulation. That drops back again in the 1930s coincident with, and this is just circumstantial, the Taylor Grazing Act, which reduced the number of grazing animals on public lands in this region.
Despite dust emission being a natural process in these regions, that disturbance of the desert soil is really critical to having large amounts of dust. By disturbance I mean breaking up of the desert crust. When well developed it makes the surface virtually impervious to wind erosion.
BB: Is the crust being disturbed by agriculture and grazing?
JD: Grazing, agriculture, energy exploration, road building, and recreational users. There have been some efforts to remove certain types of vegetation and plant others to make the forage more palatable for grazing animals. Basically, anything that busts up the crust and does it over a large enough area is going to have an effect.
The lake sediments suggest that if you remove the disturbance the crust has the potential to regenerate. Jason Neff’s work at sites at the Dugout Ranch in Canyonlands National Park, looking at dust emissions of currently grazed land, land that was grazed thirty years ago or more but hasn’t been grazed since, and land that hasn’t been grazed at all, leads us to suggest that improved land management could reduce the dust impacts on snowmelt. You could characterize it as getting water back. We’ll see; it may just be a partial offset for climate change impacts or some insurance against climate change impacts directly on the snow and in the source regions.
BB: Climate models predict a seven to twenty percent reduction in Colorado River flow by 2050 due to human-induced climate change. If you compound this with an average five percent loss of water each year, what is the net effect?
JD: It’s tempting to add those together, but there’s a nuance to it. The biggest impact on the timing of snowmelt due to dust comes in bigger snow years or in areas that receive more snow. The amount of snow on the ground determines in large part the magnitude of the impact on timing, which controls the evaporative processes. If climate impacts reduce the snow accumulation, the fractional dust impact will be reduced. That’s not necessarily good news: the dust will still have an impact but the actual number may be reduced. It would be foolish not to take advantage of any potential to mitigate the dust mechanisms.
This isn’t a remove all humans from the equation kind of solution, but identifying hotspots for emission and changing land management practices…
BB: And taking the study results into consideration and working them into land management practices?
JD: It’s easy to wrap everything up in the term “land management practices,” but a lot of the dust emission is coming from the Navaho nation lands. The Navaho people have been socially and economically marginalized, to put it kindly. Range conditions show it. It’s not as simple as saying you need to change your land management practices. It’s going to require social and economic engagement.
BB: The Colorado River Compact and Law of the River legislation is actually based on a misunderstanding of the river’s normal conditions. Why is that?
JD: The time period over which they averaged the flow in order to divide up the river was an anomalously high flow period. The river is over allocated. Currently, the upper basin states are not using their full allocation and that “extra water” has been fairly reliably delivered to the lower basin and kept Lake Powell and Mead somewhat full.
BB: Say mitigation measures do cut out this five percent yearly loss. Would it be enough to fill the lakes back up?
JD: All the main stem storage on the Colorado River adds up to the capacity of four years of river flow. If we change things by five percent of annual flow it’s not going to fill things up right away, but that five percent is twice Las Vegas’ current water allocation. It’s about half the annual shortfall in Lake Mead.
If we were somehow able to “regain” the five percent it’s not an inconsequential amount of water, but it’s also not a silver bullet. Now we’re good, don’t worry about climate change – that’s not the thing at all. Anything we can do to restore range conditions in the dust emission areas and reduce dust impacts on snowmelt will be helpful.