Impacts of the lowest-impact animal products typically exceed those of vegetable substitutes, providing new evidence for the importance of dietary change.
Cumulatively, our findings support an approach where producers monitor their own impacts, flexibly meet environmental targets by choosing from multiple practices, and communicate their impacts to consumers.
A small number of producers create much of the impact. Just 15% of beef production creates ~1.3 billion tonnes of CO2 equivalents and uses ~950 million hectares of land.
Across all products, 25% of producers contribute on average 53% of each product’s environmental impacts [across 5 indicators: GHG emissions, land use, terrestrial acidification,eutrophication, and scarcity-weighted freshwater withdrawals]. This variation and skew highlights potential to reduce impacts and enhance productivity in the food system.
Researchers found that the variability in the food system fails to translate into animal products with lower impacts than vegetable equivalents. For example, a low-impact (10th percentile) litre of cow’s milk uses almost two times as much land and creates almost double the emissions as an average litre of soymilk.
Reducing consumption of animal products by 50% by avoiding the highest-impact producers achieves 73% of the previous scenarios GHG emission reduction for example.
Irrigation returns less water to rivers and groundwater than industrial and municipal uses and predominates in water-scarce areas and times of the year, driving 90 to 95% of global scarcity weighted water use
Further, lowering consumption of discretionary products (oils, alcohol, sugar, and stimulants) by 20% by avoiding high-impact producers reduces the greenhouse gas emissions of these products by 43%. This creates a multiplier effect, where small behavioural changes have large consequences for the environment
Communicating average product impacts to consumers enables dietary change and should be pursued
New research highlights the environmental impacts of thousands of food producers and their products, demonstrating the need for new technology to monitor agriculture and environmental labels on food products.
They found large differences in environmental impact between producers of the same product. High-impact beef producers create 105kg of CO2 equivalents and use 370m2 of land per 100 grams of protein, a huge 12 and 50 times greater than low-impact beef producers. Low-impact beef producers then use 36 times more land and create 6 times more emissions than peas.
Aquaculture, assumed to create relatively little emissions, can emit more methane, and create more greenhouse gases than cows per kilogram of liveweight. One pint of beer, for example, can create 3 times more emissions and use 4 times more land than another. This variation in impacts is observed across all five indicators they assess, including water use, eutrophication, and acidification. [5 indicators: GHG emissions, land use, terrestrial acidification,
eutrophication, and scarcity-weighted freshwater withdrawals]
“Two things that look the same in the shops can have very different impacts on the planet. We currently don’t know this when we make choices about what to eat. Further, this variability isn’t fully recognised in strategies and policy aimed at reducing the impacts of farmers.” says Joseph Poore from the Department of Zoology and the School of Geography and Environment.
…Specifically the researchers found that the variability in the food system fails to translate into animal products with lower impacts than vegetable equivalents. For example, a low-impact (10th percentile) litre of cow’s milk uses almost two times as much land and creates almost double the emissions as an average litre of soymilk.
….Reducing consumption of animal products by 50% by avoiding the highest-impact producers achieves 73% of the previous scenarios GHG emission reduction for example. Further, lowering consumption of discretionary products (oils, alcohol, sugar, and stimulants) by 20% by avoiding high-impact producers reduces the greenhouse gas emissions of these products by 43%. This creates a multiplier effect, where small behavioural changes have large consequences for the environment….
J. Poore, T. Nemecek. Reducing food’s environmental impacts through producers and consumers. Science, 2018 DOI: 10.1126/science.aaq0216
Food’s environmental impacts are created by millions of diverse producers. To identify solutions that are effective under this heterogeneity, we consolidated data covering five environmental indicators; 38,700 farms; and 1600 processors, packaging types, and retailers. Impact can vary 50-fold among producers of the same product, creating substantial mitigation opportunities. However, mitigation is complicated by trade-offs, multiple ways for producers to achieve low impacts, and interactions throughout the supply chain. Producers have limits on how far they can reduce impacts. Most strikingly, impacts of the lowest-impact animal products typically exceed those of vegetable substitutes, providing new evidence for the importance of dietary change. Cumulatively, our findings support an approach where producers monitor their own impacts, flexibly meet environmental targets by choosing from multiple practices, and communicate their impacts to consumers.
From the paper:
….Today’s food supply chain creates ~1 3.7 billion metric tons of carbon dioxide equivalents (CO2eq), 26% of anthropogenic GHG emissions. A further 2.8 billion metric tons of CO2eq (5%) are caused by nonfood agriculture and other drivers of deforestation(17). Food production creates ~32% of global terrestrial acidification and ~78% of eutrophication. These emissions can fundamentally alter the species composition of natural ecosystems, reducing biodiversity and ecological resilience (19). The farm stage dominates, representing 61% of food’s GHG emissions (81%including deforestation), 79% of acidification, and 95% of eutrophication (table S17). Today’s agricultural system is also incredibly resource intensive, covering ~43% of the world’s ice- and desert-free land. Of this land, ~87% is for food and 13% is for biofuels and textile crops or is allocated to nonfood uses such as wool and leather.We estimate that two-thirds of freshwater withdrawals are for irrigation. However, irrigation returns less water to rivers and groundwater than industrial and municipal uses and predominates in water-scarce areas and times of the year, driving 90 to 95% of global scarcity weighted water use (17).
….Communicating average product impacts to consumers enables dietary change and should be pursued. Though dietary change is realistic for any individual, widespread behavioral change will be hard to achieve in the narrow time frame remaining to limit global warming and prevent further, irreversible biodiversity loss. Communicating producer impacts allows access to the second scenario, which multiplies the effects of smaller consumer changes.
Forest thinning could increase water flow from Sierra Nevada watersheds by as much as 10 percent.
The U.S. Forest Service says that 6 to 8 of the 21-million acres it manages in California need immediate restoration. Another 58 million acres nationally also require restoration. For California alone, restoration costs are estimated at $5 to $10 billion. But, according to the study authors, the restoration might help pay for itself.
There are too many trees in Sierra Nevada forests, say scientists. That may come as a surprise to those who see dense, verdant forests as signs of a healthy environment. After all, green is good, right? Not necessarily. When it comes to the number of trees in California forests, bigger isn’t always better….
That’s in part because trees use lots of water to carry out basic biological tasks. In addition, they act as forest steam stacks, raking up water stored in the ground and expelling it as vapor into the atmosphere, where it’s accessible to humans and forest ecosystems only when it falls back to Earth as rain and snow.
That process — by which plants emit water through tiny pores in their leaves — is known as evapotranspiration. And according to researchers, excessive evapotranspiration may harm a fragile California water system, especially during prolonged, warm droughts.
New research published this week in the journal Ecohydrology shows that water loss from evapotranspiration has decreased significantly over the past three decades. That’s due in large part to wildfire-driven forest thinning — a finding with important implications for forest and water management.
A century of forest management had kept wildfires to a minimum. But without fire, Sierra forests grew very dense. In recent decades, new policies have allowed nature to take its course, with wildfires helping to thin out overgrown forests.
Researchers have found in a nationwide survey that members of the public are more willing to pay for improved water quality than other ecosystem services such as flood control or protecting wildlife habitats.
….”Our findings support the notion that ecosystem service programs need to happen at the local level,” said Francisco Aguilar, associate professor of forestry in the School of Natural Resources, which is located in the MU College of Agriculture, Food and Natural Resources. “People in different areas of the country have different priorities, and that’s hard to coordinate at a national level. If someone lives in a flood plain, they are going to be a lot more willing to pay for flood controls. Still, people from around the nation consistently seem to be willing to pay for water quality improvements.”…
We need to increase our use of nature-based solutions – where we work more with nature – says a new report on global water management by the United Nations.
World Water Development Report 2018— demonstrates how nature‐based solutions (NBS) use or mimic natural processes to enhance water availability (e.g., soil moisture retention, groundwater recharge), improve water quality (e.g., natural and constructed wetlands, riparian buffer strips), and reduce risks associated with water‐related disasters and climate change (e.g., floodplain restoration, green roofs). Read more / Download the report in English | Français | Español
….“We need new solutions in managing water resources,” says Audrey Azoulay, Director-General of UNESCO, “so as to meet emerging challenges to water security caused by population growth and climate change.”
Greater use of nature-based solutions will help us toward a more holistic approach to managing global water resources. Image: CP/pixabay composite.
The 2018 United Nations World Water Development Report featured recently at the 8th World Water Forum in Brasilia, Brazil.
Holistic approach to water management
The report argues that nature-based solutions are one of the many essential tools for moving toward “a more holistic approach to water management.”
Nature-based solutions support the idea that water is not an isolated element but an inseparable part of a cycle of evaporation, precipitation, and absorption through the soil.
Grasslands, forests, and wetlands – and the extensive vegetation cover that they provide – have a profound effect on the water cycle and by focusing on them we can do much to improve the amount and quality of water that is available.
The report says that we need to make more use of environmental engineering that focuses on “green infrastructure” rather than just “grey infrastructure” solutions provided by traditional civil engineering.
This does not mean that we do not continue to seek civil engineering solutions in the form of irrigation canals, reservoirs, and water treatment plants, but look to increase nature-based solutions to complement them.
Benefits of ‘green infrastructure’
Green infrastructure has much to offer water-intensive applications such as agriculture. For example, it can help to reduce soil erosion, pollution, and the amount of water required by making irrigation systems more efficient.
An example of this is the change that has occurred in recent decades in the Indian state of Rajasthan, which suffered one of its worst droughts ever in 1986.
In the years that followed, collaboration between an NGO and local communities established ways of harvesting water that regenerated forests and soils.
As a result, forest cover in the state increased by 30 percent, groundwater levels went up several meters, and productivity of croplands improved.
“For too long,” says Azoulay, “the world has turned first to human-built, or ‘grey’, infrastructure to improve water management. In so doing, it has often brushed aside traditional and Indigenous knowledge that embraces greener approaches.”….
Overall, the model results calculated a decline in global water storage during the study period, while GRACE data indicate it was on the rise. However, the study notes that while the climate increased water storage globally, humans caused significant declines in certain regions.
But ensuring water availability for human consumption and agriculture is in many cases a regional to local issue, and we should put increased emphasis on analyses at this scale by, for example, integrating local data.
Posted: 22 Jan 2018 01:47 PM PST
Researchers have found that calculations of water storage in many river basins from commonly used global computer models differ markedly from independent storage estimates from GRACE satellites.
….”People are depending more and more on global models to determine projections of the impacts of human water use and climate on water resources,” said lead author Bridget Scanlon, a senior research scientist at the university’s Bureau of Economic Geology. “We are now able to evaluate water storage changes from models with GRACE data, which suggests that the models may underestimate large water storage changes, both large declining and rising storage trends.”
….Overall, the model results calculated a decline in global water storage during the study period, while GRACE data indicate it was on the rise. However, the study notes that while the climate increased water storage globally, humans caused significant declines in certain regions. The study area covered about 63 percent of global land area and excluded Greenland and Antarctica because most of the water in those areas is trapped in glaciers or ice sheets….
…The study also notes that scientists should work on improving regional assessments. “GRACE is great because it highlights the global picture of what’s happening with global water storage, and at a coarse grid-scale it’s really nice to see what’s happening,” Scanlon said. “But ensuring water availability for human consumption and agriculture is in many cases a regional to local issue, and we should put increased emphasis on analyses at this scale by, for example, integrating local data. The specific situation could be much better investigated than with global-scale studies only.”
Bridget R. Scanlon, Zizhan Zhang, Himanshu Save, Alexander Y. Sun, Hannes Müller Schmied, Ludovicus P. H. van Beek, David N. Wiese, Yoshihide Wada, Di Long, Robert C. Reedy, Laurent Longuevergne, Petra Döll, Marc F. P. Bierkens. Global models underestimate large decadal declining and rising water storage trends relative to GRACE satellite data. Proceedings of the National Academy of Sciences, 2018; 201704665 DOI: 10.1073/pnas.1704665115
Findings reveal that a variety of management strategies have the potential to improve soil water infiltration rates, with possible benefits for soil carbon as well.
Researchers identified a shortage of well-replicated and detailed experiments in all grazing management categories, and call for additional research of both soil water and soil carbon properties for these critical agroecosystems
The potential to improve soils to help farmers and ranchers adapt to and mitigate climate change has generated significant enthusiasm. Within this discussion, grasslands have surfaced as being particularly important, due to their geographic range, their capacity to store substantial quantities of carbon relative to cultivated croplands and their potential role in mitigating droughts and floods. However, leveraging grasslands for climate change mitigation and adaptation will require a better understanding of how farmers and ranchers who rely on them for their livelihoods can improve management and related outcomes.
To investigate opportunities for such improvements, we conducted a meta-analysis of field experiments that investigated how soil water infiltration rates are affected by a range of management options: adding complexity to grazing patterns, reducing stocking rates or extended rest from grazing. Further, to explore the relationships between observed changes in soil water infiltration and soil carbon, we identified papers that reported data on both metrics. We found that in 81.9% of all cases, responses of infiltration rates to identified management treatments (response ratios) were above zero, with infiltration rates increasing by 59.3 ± 7.3%. Mean response ratios from unique management categories were not significantly different, although the effect of extended rest (67.9 ± 8.5%, n = 140 from 31 experiments) was slightly higher than from reducing stocking rates (42.0 ± 10.8%; n = 63 from 17 experiments) or adding complexity (34.0 ± 14.1%, n =17 from 11 experiments). We did not find a significant effect of several other variables, including treatment duration, mean annual precipitation or soil texture; however, analysis of aridity indices suggested that grazing management may have a slightly larger effect in more humid environments. Within our database, we found that 42% of complexity studies, 41% of stocking rate studies and 29% of extended rest studies also reported at least some measure of soil carbon. Within the subset of cases where both infiltration rates and carbon were reported, response ratios were largely positive for both variables (at least 64% of cases had positive mean response ratios in all management categories).
Overall, our findings reveal that a variety of management strategies have the potential to improve soil water infiltration rates, with possible benefits for soil carbon as well. However, we identified a shortage of well-replicated and detailed experiments in all grazing management categories, and call for additional research of both soil water and soil carbon properties for these critical agroecosystems.
Planting 20 percent more trees in our megacities would double the benefits of urban forests, like pollution reduction, carbon sequestration and energy reduction. The authors of the study say city planners, residents and other stakeholders should start looking within cities for natural resources and conserve the nature in our urban areas by planting more trees….
T. Endreny, R. Santagata, A. Perna, C. De Stefano, R.F. Rallo, S. Ulgiati. Implementing and managing urban forests: A much needed conservation strategy to increase ecosystem services and urban wellbeing. Ecological Modelling, 2017; 360: 328 DOI: 10.1016/j.ecolmodel.2017.07.016
Bone dry in Southern California, and below average precip throughout CA
All of California is now experiencing well-below-average precipitation for the season to date. Southern California has seen almost no precipitation at all…
Why has California been so dry? (Regular blog visitors already know where I’m going with this.) Well, a remarkably persistent zone of atmospheric pressure has been present more often than not across the region for the past few months. ….More recently, the bigger & stronger West Coast ridge has pushed the Pacific storm track even further north. Remarkably, this powerful ridge has forced several very moist atmospheric river storms over the mid-Pacific to make a hard “left turn” over the open ocean–veering directly northward and bringing almost inconceivably heavy snowfall to the coastal mountains of southern Alaska.
Thomas Fire becomes largest wildfire in modern California history–in December
The Thomas Fire has become the largest wildfire in modern California history–in December. (Via NASA)
….While December wildfires are not unheard of in this part of the world, the extent and severity of the December 2017 fires in SoCal really is unprecedented in California history. The Thomas Fire–which has now burned nearly 275,000 acres and over a thousand structures in Ventura and Santa Barbara counties–yesterday became the single largest wildfire in modern California history. That this dubious milestone was reached in December, which is typically the midst of the California rainy season, is truly extraordinary. Indeed, recent months have brought not only near-record low precipitation, but also record-high temperatures across a wide swath of SoCal….
…..While long-term humidity records are hard to come by in most spots, all signs suggest that these were at or near record-low humidity values for many of these recording stations (and certainly for the time of year).
Is this (another) return of the Ridiculously Resilient Ridge?
Persistent high pressure ridging over the American West has kept conditions unusually warm and dry so far this autumn and early winter, especially across Southern California and Arizona. (NOAA via ESRL)……we’re not in Triple R [ridiculously resilient ridge] territory quite yet, but we’re getting close. We have certainly witnessed the return of resilient ridging near California, but I don’t think we’ve yet reached the “ridiculous” level of multi-month persistence that occurred during the height of the recent California drought. Should present conditions persist through January, and if seasonal precipitation has not started to recover from its early deficit by that time, I may have to revise that answer.
…The not-so-good news: parts of Southern California that depend exclusively on local water supplies (such as much of Santa Barbara and Ventura counties) never really recovered from the last drought, and these regions remain quite susceptible to the impacts of drought re-intensification. And even further north, forested regions remain quite stressed as a result from the previous multi-year drought, and tree mortality in the Sierra Nevada remains far above historically observed levels.
Unfortunately, 2+ weeks of unusually dry conditions still probable….The “Warm West/Cool East” pattern discussed in the previous post is still quite prominent over North America. The present West Coast dryness is largely consistent with seasonal model predictions for this winter, and those same models presently suggest that the present pattern is likely to persist for much of the California rainy season.All of this is to say: it’s still too early to say whether we’re headed into a new drought, though there are some compelling signs that we may be (especially in Southern California). And even in a dry year, California can still experience big storms and very wet months. But at this point, it probably makes sense to start thinking about the possibility of yet another big swing in California–from drought, to flood, and then (perhaps) back again.
Jakartans are digging illegal wells, drip by drip draining the underground aquifers on which the city rests — like deflating a giant cushion underneath it. About 40 percent of Jakarta now lies below sea level.
And it has to deal with mounting threats from climate change which exacerbates scores of other ills— runaway development, a near-total lack of planning, next to no sewers and only a limited network of reliable, piped-in drinking water — all posing an imminent threat to the city’s survival.
Hydrologists say the city has only a decade to halt its sinking. If it can’t, northern Jakarta, with its millions of residents, will end up underwater, along with much of the nation’s economy.
The aquifers aren’t being replenished, despite heavy rains and the abundance of rivers, because more than 97 percent of Jakarta is now smothered by concrete and asphalt. Open fields that once absorbed rain have been paved over. Shores of mangroves that used to help relieve swollen rivers and canals during monsoons have been overtaken by shantytowns and apartment towers
…With climate change, the Java Sea is rising and weather here is becoming more extreme. Earlier this month another freakish storm briefly turned Jakarta’s streets into rivers and brought this vast area of nearly 30 million residents to a virtual halt….But global warming turned out not to be the only culprit behind the historic floods that overran Rasdiono’s bodega and much of the rest of Jakarta in 2007. The problem, it turned out, was that the city itself is sinking.
In fact, Jakarta is sinking faster than any other big city on the planet, faster, even, than climate change is causing the sea to rise — so surreally fast that rivers sometimes flow upstream, ordinary rains regularly swamp neighborhoods and buildings slowly disappear underground, swallowed by the earth. The main cause: Jakartans are digging illegal wells, drip by drip draining the underground aquifers on which the city rests — like deflating a giant cushion underneath it. About 40 percent of Jakarta now lies below sea level.
Coastal districts, like Muara Baru, near the Blessed Bodega, have sunk as much as 14 feet in recent years….
…Climate change acts here as it does elsewhere, exacerbating scores of other ills. And in Jakarta’s case, a tsunami of human-made troubles — runaway development, a near-total lack of planning, next to no sewers and only a limited network of reliable, piped-in drinking water — poses an imminent threat to the city’s survival….
…The aquifers aren’t being replenished, despite heavy rains and the abundance of rivers, because more than 97 percent of Jakarta is now smothered by concrete and asphalt. Open fields that once absorbed rain have been paved over. Shores of mangroves that used to help relieve swollen rivers and canals during monsoons have been overtaken by shantytowns and apartment towers.
There is always tension between immediate needs and long-term plans. It’s a similar story in other sinking giants like Mexico City. Here, all of the construction, combined with the draining of the aquifers, is causing the rock and sediment on which Jakarta rests to pancake….
….JanJaap Brinkman, a hydrologist who for decades has been studying Jakarta for the Dutch water research institute Deltares, sympathizes with residents of communities like Akuarium and Tongkol. Eviction isn’t a cure-all, or even possible, he said, considering how many countless thousands of Jakartans now live atop the canals and rivers in informal developments. At the same time, Mr. Brinkman stressed, moving people is necessary, and bungled evictions squander a meager reservoir of good will and precious time.
“We need big steps now,” he said. “If all the discussions get tied up with fishermen and development, there will eventually be a massive calamity and deaths and no choice but to give up on whole parts of Jakarta.”
….The most ambitious move by the city is the construction of what’s called the Coastal Wall, now rising like a black cliff from Jakarta Bay. It’s a quasi-temporary barrier to hold back the rising sea and compensate for subsidence — built extra high because, like the rest of North Jakarta, it is expected to sink, too. With subsidence at the current rate, the Coastal Wall itself may be underwater by 2030.
….Tokyo was in a similar predicament after World War II, he likes to point out. It had sunk about 12 feet since 1900. But the city poured resources into new infrastructure and established stricter rules about development, and within a decade or two made itself a global model of urban innovation, better able to cope with the effects of climate change.
“Jakarta could become a 21st-century version of Tokyo in the 20th century, an example for urban redevelopment,” Irvan Pulungan, the climate change adviser to the city’s new governor, imagined.
But “a city that can’t deliver basic services is a failed city,” he added. ”On top of conventional issues like flooding and urbanization we now have climate change, tipping the scale. And at this rate, people will be fighting in the streets for increasingly limited resources like clean water and safe living spaces.”
Like Tokyo half a century ago, Jakarta is at a turning point, he said: “Nature will no longer wait.”