Dispatches

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Biofuel crops destroying US grasslands

Janet Pelley

The biofuels boom has boosted US corn and soybean cultivation to record levels, but has this expansion come at the cost of damaging more land? According to the US Department of Agriculture (USDA), the net acreage of cropland has increased negligibly since biofuels became popular. However, a new study shows that USDA's net measure masks the fact that farmers are shifting crops onto undisturbed grasslands at high rates while retiring existing cropland (Environ Res Lett 2015; doi:10.1088/1748-9326/10/4/044003).

To prevent the biofuel gold rush from destroying natural habitat and releasing carbon stored in soils, the US Renewable Fuels Standard (RFS) withholds “renewable credits” for feedstocks grown on land that had not been farmed before 2007, says Tyler Lark, lead author of the study and a land-change scientist at the University of Wisconsin–Madison (Madison, WI). The US Environmental Protection Agency relies on the USDA's net annual cropland acreage to monitor compliance with the RFS. Yet Lark suspected that there were undetected changes underlying the static net USDA figures.

Figure 1.

US farmers are taking over undisturbed grasslands to grow biofuels.

Lark and his team analyzed a new USDA satellite-based map that recorded nationwide crop cover for each year since 2008. Integrating other land-cover databases, the researchers tracked the expansion and abandonment of farmland from 2008 to 2012, coinciding with the biofuel boom.

The scientists found that 7.34 million acres of land nationwide, an area roughly the size of Maryland, had been converted to crop production during that time period. Nearly 80% of the new cropland came from prairie, pasture, and hay fields. “If you convert native prairie to cropland, it's nearly impossible to regain the biodiversity and carbon-storage capacity that's lost upon tilling”, Lark says. Over the course of the study, the researchers estimated that the carbon emissions associated with converting the land to grow corn and soybeans could be equivalent to a year's worth of CO2 releases from 34 coal-fired power plants. Lark explains that the widespread expansion of farmland could not be seen from the total net figures because while farmers expanded cultivation, they abandoned 4.36 million acres of existing cropland, much of it destined for a conservation program.

“The study hints that renewable fuel policies may be generating an unintended, but substantial, carbon debt”, says Chris Wright, a landscape ecologist at the University of Minnesota–Duluth (Duluth, MN). The findings support the need for enforcing the RFS feedstock provisions through a spatially explicit framework and broadening policies that discourage grassland conversion, he concludes.

Century-long mercury increase in ivory gulls

Patrick Monahan

Even in the remote high latitudes, humans' environmental impacts extend far into the past. One way to observe these long-term impacts – short of making a yearly pilgrimage to the northern shores of Canada – is to study Arctic specimens housed in museums. A group of researchers led by Alex Bond (a postdoctoral researcher at the University of Saskatchewan, Saskatoon) used this strategy to look at changes in ivory gull (Pagophila eburnea) mercury exposure over the past 130 years (P R Soc B 2015; doi:10.1098/rspb.2015.0032).

“Ivory gulls scavenge on dead marine mammals – things like seals that polar bears have killed, or beached whales – so they really are at the top of the food chain”, Bond explains. This makes the birds especially vulnerable to pollutants that accumulate in body tissues – such as mercury, which is released into the environment by burning coal and through other industrial processes.

Bond and his colleagues tested feather samples from museum-stored specimens dating back to the year 1877 for methyl mercury, a toxic form of the metal that builds up in living gulls' tissues and feathers as they consume mercury-contaminated food. The researchers also used stable-isotope analysis to assess whether changes in the birds' diet could have affected mercury intake. Bond explains that “over that time, the gulls' diet hadn't changed at all – but mercury concentrations in the adults went up by a factor of 45, about 1.6% a year”.

Mercury concentrations are also increasing in other Arctic wildlife but not to this extent. High levels of the metal can make it difficult for ivory gulls, currently listed as near threatened by the IUCN, to successfully rear their young due in part to eggshell thinning. So this rapidly increasing mercury intake may be contributing to the species' observed decline – an 80% decrease in numbers since the 1980s, which has left only ~500 breeding pairs in the Canadian Arctic.

Like the ivory gull, natural-history collections are declining, thereby limiting researchers' ability to look into the past. “We couldn't have done it without museum collections”, admits Bond. “For us to go up there every year to collect ivory gulls would have been completely impossible.”

Concern over lowering of green standards in India

Dinesh C Sharma

Prime Minister Narendra Modi's government, in place since May 2014, has decided to relax environmental regulations for industries and has slashed the annual budget earmarked for environmental protection. The Indian Ministry of Environment, Forests and Climate Change (MOEFCC) has been allocated nearly 20% less funding for 2015–2016 as compared to the last fiscal year. As a result, less money will be available for specific conservation projects such as “Project Tiger”, and for environmental research in general.

In its drive to promote India as a manufacturing destination, to attract foreign investment, and to facilitate faster approval of projects requiring environmental impact assessments (EIAs), the government has eased environmental regulations. In April, MOEFCC published standard “terms of reference” for conducting EIAs for 39 types of industry and infrastructure projects, which – according to Environment Minister Prakash Javadekar – will reduce the time required for project approval from 1 year to 30 days.

“The focus is on weakening environmental governance, and making compliance easy and appraisal less rigorous”, points out Himanshu Thakkar, head of the South Asia Network on Dams, Rivers and People (New Delhi, India); “for instance, EIA terms for river valley and hydro projects do not cover climate-change-related impacts or account for possibilities of [natural] disasters”. Safety clauses, such as those requiring mandatory consent by local communities before initiation of large projects in forested areas, have been removed. New projects in proximity to national parks and sanctuaries no longer require approval from the National Board for Wildlife. “The thrust is clear: promotion of industries, mega-projects, economic zones, and dams – at any cost”, warns Ritwick Dutta (EIA Resource and Response Centre, New Delhi).

MOEFCC has proposed further reforms in environmental laws, including those pertaining to forest and biodiversity protection. The ministry plans to implement recommendations from a review panel – detailed in the 2014 “Report of the High Level Committee to Review Various Acts Administered by the MOEFCC” (http://bit.ly/1FQBWEb) – suggesting establishment of a new regulatory system based on “self-certification” by industry. “While environmental decision making needs to be reformed, the objective should be to safeguard public interest and the environment, and not to promote economic growth that causes irreversible ecological damage”, says Leo Saldanha, coordinator of Environment Support Group (Bangalore, India). Dutta fears that The National Green Tribunal, which is the current appellate authority for all “green” clearances, will be rendered powerless if the panel's suggested reforms are accepted. “This report is designed to dismantle the very foundation of the environmental justice system in India”, he concludes.

The price of survival

Claire Miller

Twenty threatened species native to Australia may have won the lottery for survival under a conservation management plan that – for the first time – estimates the cost of their recovery. Zoos Victoria (Melbourne) released the AU$30 million, 5-year plan in March in an appeal for donors to cover the AU$20 million shortfall in its Fighting Extinction budget. The plan includes captive breeding, habitat restoration, and monitoring recovery. “Zoos are like ‘intensive care units’ for wildlife”, explains Director of Conservation Rachel Lowry (Zoos Victoria, Melbourne). “Species often don't come into zoos until they're really in trouble, and often we're called in too late. We needed to be proactive and examine the trajectory of endangered species. Once we did this, it became clear what we had to do.”

But the plan has sparked debate about the best use of scarce funds. Although its 20 priority species are iconic and charismatic, Australia has more than 1760 endangered animals and plants. Conservation scientist Hugh Possingham (University of Queensland, Brisbane) agrees that the clear, cost-specific plan is a big step forward, but he advocates a rigorous triage approach: prioritizing conservation on the basis of extinction and recovery likelihood, costs, and taxonomic and ecological importance, as well as on the “public care” factor. “What offends people about triage is that we're being transparent about which species we choose to spend money on, and why. When the global rate of extinction is 1000 times the background rate, then whatever we're doing now isn't working very well. New Zealand is now conserving more than twice as many species as before, using this cost-effective approach.” On the positive side, triage lays bare the true cost to society if it wants to halt extinction; in Australia's case, this amounts to AU$200 million a year. “It sounds like a lot, but it's chicken feed”, continues Possingham. “It's 1% of the annual defense budget, or three cappuccinos per person per year.”

Figure 2.

Worth saving? Eastern barred bandicoots (Perameles gunnii) are extinct in the wild on mainland Australia.

As it is, even the Zoos Victoria plan provides no guarantees for its chosen species. Ecologist David Lindenmayer (Australian National University, Canberra) notes that AU$4 million for breeding and habitat restoration will not save Leadbeater's possum (Gymnobelideus leadbeateri), for example, unless the interrelated threats of logging and fire are addressed. “Documents like this are a good start, but they don't tackle the real drivers of extinction”, he warns.

Changing Alaska habitat complicates species forecasts

Virginia Gewin

Ponds in the Arctic tundra are disappearing, according to a recent study (J Geophys Res-Biogeo 2015; doi:10.1002/2014JG002778). Using historical photographs and satellite images taken between 1948 and 2010, researchers analyzed 2800 ponds in the northern region of Alaska's Barrow Peninsula. Over time, the number of ponds decreased by about 17%, while pond size shrank by an average of 33%.

Warming temperatures are to blame – directly and indirectly. Ponds dry up due to heat, but the warming permafrost also releases nutrients into the water, encouraging plant growth. As a result, the gradual process of small ponds transforming into lakes is hampered. “If these changes continue over time, species – especially threatened and endangered waterfowl such as the Steller's eider (Polysticta stelleri) – could potentially be affected”, says study author Christian Andresen, a postdoctoral fellow at the University of Texas at El Paso.

Figure 3.

Both the number and size of Alaskan ponds, which typically would form lakes over time, are decreasing.

In January, a separate study of northwest Alaska (Climatic Change 2015; doi:10.1007/s10584-014-1302-1) also found that thawing permafrost, shrinking lakes, and changing vegetation – as well as coastal erosion and increased wildfires – could diminish habitat for many species, including migratory waterfowl. However, forest and tall shrub habitat could expand – benefiting, for example, the ruffed grouse (Bonasa umbellus). To help cut through the complexity and identify the species that will be winners or losers, the researchers projected the effects of climate change and biophysical drivers on bird and mammal habitats. “This is a first pass at quantifying the distribution and spatial patterns of habitat change; hopefully it will serve as a starting point for future work on wildlife population dynamics”, explains study author Bruce Marcot, a wildlife biologist with the US Forest Service (Portland, OR).

According to Josh Koch, a research hydrologist with the US Geological Survey (Anchorage, AK), one of the biggest shifts taking place relates to how water interacts with thawed and burned soils; “We've seen several streams flowing aboveground that suddenly disappear down a hole”, he says. “We're making progress but there's more to do to nail down the complex processes and feedbacks at work over such a large area.”

All agree that long-term data akin to those of Andresen's pond study will help achieve that goal. To that end, Marcot published an aerial-based survey of the US National Park Service's Arctic Network in 2014 (dx.doi.org/10.3133/ds846), complete with photos, videos, and GPS routes, to serve as a baseline for future efforts to conduct change analysis over time.

New life for old drywall

Ken Ferguson

Used in buildings worldwide, dry-wall comprises up to 27% of the solid waste associated with construction in North America, and most of it ends up in landfills – about 15 million tons of drywall waste in the US alone. M Anne Naeth, a Professor of Land Reclamation and Restoration Ecology at the University of Alberta (Edmonton, Canada), believes this material can be put to better use.

Drywall panels consist of gypsum – a calcium sulfate mineral – mixed with water and other ingredients to form a plaster, which is then compressed between two layers of heavy paper and dried. Naeth speculated that drywall waste could be used as a compost additive, to improve the relatively poor soils that are characteristic of land reclamation projects. “There is steadily increasing urban, industrial, and natural resource development in North America”, she explains. “One of the main outcomes of this disturbance is the loss of soil organic matter, which provides water-holding capacity, improves soil structure, and contains many of the nutrients required by plants.”

Mixing coarse and ground drywall with three biosolids-based composts and one manure-based compost, Naeth and her team examined how the various compost combinations affected the establishment and growth of three grass species sown in three different soils typical of reclamation sites. Seedling establishment and growth were relatively unaffected by drywall addition, while plant biomass was generally higher in soils treated with biosolids compost supplemented with drywall than in soils treated with traditional biosolids compost. Adding drywall to manure compost did not augment plant growth. “Enhanced plant growth with use of drywall compost was feedstock- (ie biosolids versus manure) and species-specific”, according to Naeth. “Before starting a large-scale operation, each producer would need to test with their particular compost feedstocks and compost process.”

“Compost often requires a bulking agent; wood chips or sawdust are commonly used, but drywall could be an alternative source”, she adds. “The key focus is on finding disposal methods for drywall other than landfilling. We must identify innovative methods for disposing of industrial waste products to reduce our impact on – and even, as in this case, to enhance – the environment.”

Chinese citizens protest waste incineration facilities

Ganlin Huang

This April, in response to increasingly violent public protests, local government officials in Luoding, a city in southern China's Guangdong province, cancelled the construction of a waste incinerator plant, which had been due to become operational in October of this year. Concerned with the threat of increased air and water pollution, thousands of local residents held rallies against the project. Improper waste burning generates dioxins – which have been linked to cancer, as well as reproductive and immune system problems – and although modern waste-burning technology is designed to minimize dioxin emissions, citizens were not convinced that the proposed incinerator would comply with the required emission controls.

This is not the first time that provincial authorities in China have terminated or postponed incinerator projects due to public pressure. In 2008, the Beijing municipal government cancelled the opening of a planned incinerator following protests by local inhabitants, and the Hangzhou city government did the same in 2014.

Despite the apparent success of civic action in blocking waste incinerators at certain locations, some of these projects have simply been relocated elsewhere. In 2011, China produced 190 million tons of solid waste, representing 14.5% of the total global amount. China's waste is projected to increase annually by 3–5% due to growing urban populations and increasing per-capita consumption. Most of this waste goes to landfills, and is later burned to generate electricity. This creates space for more garbage, which municipal authorities see as a good solution to their disposal problems. China plans to build more than 300 new incinerators nationwide by 2017, with a combined daily processing capacity of over 300 000 tons, or 30% of the nation's solid waste.

Many middle-aged Chinese can recall selling used paper products and containers for pocket money when they were children, and a small amount of recycling still occurs in China. Awareness of these issues is increasing among the public, but the country lacks a proper waste classification system. Locally organized pilot waste-sorting projects have met with limited success, given that there are no facilities to receive and process the recyclable materials collected. “We spent a huge amount of time and effort advocating recycling in 2008”, said Lin Wang, a retiree living in Beijing who used to run volunteer recycling programs in the city, “but we just ended up with a room full of dead batteries and tons of plastic bags that no one would take”.

Re-timing traffic lights reduces urban pollution

Lindsay Deel

Poorly timed traffic signals aggravate impatient drivers and harm the environment. Re-programming these signals is a quick, low-cost method of reducing fuel consumption and vehicular CO2 emissions in cities, but using computer simulations to model all of the complex interactions that go into the timing of stoplights is often computationally expensive enough to be impractical for transportation agencies. In a new study (Transport Sci 2015; doi:10.1287/trsc.2014.0554), scientists at the Massachusetts Institute of Technology (MIT; Cambridge, MA) have designed a system that relies on vehicle- and city-level data to identify strategies for minimizing travel times and fuel consumption. “What we do”, said lead author Carolina Osorio in a recent MIT press release, “is develop algorithms that allow transportation agencies to use high-resolution models of traffic to solve optimization problems”.

Figure 4.

Optimized timing of traffic signals in urban areas can reduce vehicle emissions.

The challenge is finding the proper balance between detail and processing speed to make the model both useful for and accessible to municipal agencies with limited computer resources. Osorio and her MIT co-author Kanchana Nanduri used traffic in Lausanne, Switzerland, as a test case for their algorithm. They simulated the behavior of thousands of individual cars, buses, and motorcycles, each with different characteristics and fuel efficiencies, on a daily basis. They even considered how small changes in traffic-signal patterns might alter driver behavior – for instance, some people might choose a different route if a particular stoplight is slow.

The new simulation-based approach can even help city agencies to estimate environmental impacts when they propose traffic pattern changes. Osorio says that environmental factors can be incorporated into the design plan so agencies no longer have to evaluate these impacts after the fact, as is currently the practice. Osorio is now working with officials from the New York City Department of Transportation, including Deputy Director Mohamad Talas from the System Engineering Division, to test large-scale traffic-signal control in Manhattan using this methodology. “We implement the model in roadway network areas where congestion continues to persist”, says Talas. “This [has a] direct effect on people's quality of life, in both their travel and in their daily life.”

Shrinking water's carbon footprint

Robin Meadows

Supplying people with water uses so much energy – one-fifth of the electricity and one-third of the natural gas used in California – that it also has a hefty carbon footprint. But now, for the first time, the Sonoma County Water Agency (SCWA) is on track to deliver carbon-neutral water this year. “We started our Carbon Free Water program because the agency is one of the largest electricity users in the county”, says Carolyn Glanton of the SCWA Energy Resources Group (Santa Rosa, CA).

The program owes its success partly to water conservation, which automatically saves the power required to supply water, and to upgraded equipment. Encouraging people to use less water cut energy use by 15%, and switching to more efficient pumps saved another 18%. “We get our water from the Russian River and it takes a lot of energy to pump it out”, Glanton continues. Pumping water from collector wells along the river accounts for 70% of the SCWA's 45 000 megawatt (MW) electricity use.

Figure 5.

Installing solar panels can help water treatment plants become carbon-neutral.

The other part of the solution was a decade-long shift to renewable energy. Today, the agency gets about half its electricity from a local landfill's biogas, a quarter from a hydroelectric dam on Lake Sonoma, and the rest from local solar installations. Other water agencies in the state could easily go carbon-neutral too. “Many [other agencies] own assets and infrastructure that could host renewable generation facilities”, claims an April 2015 Union of Concerned Scientists (Cambridge, MA) report called Clean Energy Opportunities in California's Water Sector (http://bit.ly/1FUdLVb). “The water sector is poised to become a greater part of the energy and climate solution.”

Additional renewable energy options include in-pipe hydropower and solar panels that float on reservoirs and other waters. The SCWA plans to install the latter on its water treatment ponds this year. That will make the water system a net energy producer, allowing the agency to sign a deal next year to sell 12.5 MW – enough to power 3000 homes – to Sonoma Clean Power, a local renewable energy company. Says Glanton: “I believe it will be the biggest floating solar power system in the country”.

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