….According to the report, 75 percent of the food we consume comes from just 12 plant sources and five animal sources. And just three crops — wheat, corn and rice — make up nearly 60 percent of the plant-based calories in most diets.
The lack of variety in agriculture is both bad for nature and a threat to food security, the report says. It argues that it’s essential we change our eating habits to protect the planet and ensure we are able to feed our growing global population….
….Maria Haga, the head of Crop Trust, an organization focused on preserving crop diversity, says the new campaign is on target. “We probably have globally like 30,000 plants that we could eat,” she says. “We eat roughly 150 of those.” And to have just a handful of crops be so dominant is “really a challenge for the whole food system.”
Haga says dependence on just a few crops is also a threat to food security…. If we’re to feed everyone with a changing climate, says Haga, we’ll need diverse crops that can adapt to extreme weather conditions. The planet has lost thousands of varieties of foods in the last hundred years, says Haga. And once they’re gone, they’re gone forever….
….people are beginning to wake up to the problem and to the wide variety of alternative foods, many of which he grew up eating. One example is the ancient grain fonio, which resembles couscous. “It’s a grain that’s great for the planet,” says Thiam. “And it’s gluten free; it’s drought resistant; it grows in two months; it scores low on the glycemic index, so it’s great for your health too.”… Besides grains like fonio, they include various mushrooms, beans and pulses, nuts, tubers, algae and cactuses…
Even efforts to use water more efficiently in municipal and industrial sectors won’t be enough to stave off shortages, say the authors of the new study. The results suggest that reductions in agricultural water use will probably play the biggest role in limiting future water shortages.
The new study is part of a larger 10-year U.S. Forest Service assessment of renewable resources including timber, rangeland forage, wildlife and water. …The new study finds climate change and population growth are likely to present serious challenges in some regions of the U.S., notably the central and southern Great Plains, the Southwest and central Rocky Mountain States, and California, and also some areas in the South and the Midwest.
The heart of the new analysis is a comparison of future water supply versus estimated water demand in different water-using sectors, like industry and agriculture….
Thomas C. Brown, Vinod Mahat, Jorge A. Ramirez. Adaptation to Future Water Shortages in the United States Caused by Population Growth and Climate Change. Earth’s Future, 2019; DOI: 10.1029/2018EF001091
Background from Ellie: Conservatively, managing agricultural soils for soil organic matter can sequester 5 billion tons (Gt) of CO2e out of the atmosphere globally every year, drawing down 50% of what is needed to return to a safe climate by 2050.
The UN IPCC’s recent 1.5C report called soil carbon sequestration as among the cheapest methods with the greatest potential (http://www.ipcc.ch/report/sr15/). Healthy soils are foundational to human well-being, climate stabilization and vibrant ecosystems. The sustainable management and restoration of soils enhance agricultural productivity, fresh water availability, biodiversity, and climate change preparedness with enormous potential to slow and reverse negative impacts such as droughts, floods and more (von Unger, M. & Emmer, I. 2018. Carbon Market Incentives to Conserve, Restore and Enhance Soil Carbon. Silvestrum & TNC).
all IPCC scenarios that keep us below 2°C of warming include CO2 removal –
typically about 10 billion tons CO2 yr-1. Based on the latest estimates from
the IPCC, soils management could conservatively pull 5 billion tons of CO2 out
of the atmosphere annually on croplands and rangelands by 2050, offering 50% of
the needed carbon removal, with zero additional land and water use (D. Bossio,
TNC; and, Zomer et al. Global Sequestration Potential of Increased Organic
Carbon in Cropland Soils. Scientific Reports 7.;
Vermeulen et al, A Global Agenda for Action on Soil Carbon. Nature Sustainability, Jan 2019). Equally important is avoiding future
emissions from soil by protecting existing soil carbon stocks in grasslands and
Nearly half of all insect species worldwide are in rapid decline and a third could disappear altogether, according to a study warning of dire consequences for crop pollination and natural food chains.
…”We estimate the current proportion of insect species in decline—41 percent—to be twice as high as that of vertebrates,” or animals with a backbone, Francisco Sanchez-Bayo of the University of Sydney and Kris Wyckhuys of the University of Queensland in Australia reported.
“At present, a third of all insect species are threatened with extinction.”….
….Experts estimate that flying insects across Europe have declined 80 percent on average, causing bird populations to drop by more than 400 million in three decades.
Only a few species of insects—mainly in the tropics—are thought to have suffered due to climate change, while some in northern climes have expanded their range as temperatures warm.
In the long run, however, scientists fear that global warming could become another major driver of insect demise….
They found that the largest gains in yield occurred between concentrations of 0.1 percent and 2 percent of soil organic matter. “…we now have numbers, not just unverified ideas, that if you build organic matter you can improve outcomes — such as less fertilizer and increased yield.”
Emily E. Oldfield, Mark A. Bradford, Stephen A. Wood. Global meta-analysis of the relationship between soil organic matter and crop yields. SOIL, 2019; 5 (1): 15 DOI: 10.5194/soil-5-15-2019
While policymakers often tout the benefits of increasing soil organic matter as a way to boost agricultural yield, there is limited evidence that this strategy actually works. A new study quantifies this relationship, finding that greater concentrations of organic matter indeed produce greater yields — but only to a certain point.
Specifically, they find that increasing soil organic carbon — a common proxy for soil organic matter — boosts yields until concentrations reach about 2 percent, at which level they tend to hit a saturation point. Thereafter, the researchers say, the increase in SOM begins to deliver diminished returns.
Even still, they find that roughly two-thirds of agricultural soils dedicated to two of the world’s most important staple crops — maize and wheat — fall below that 2-percent threshold, suggesting the vast potential for agricultural policies that promote increased soil organic matter.
…It is well understood that building and maintaining soil organic matter is key to soil health. (SOM refers to organic matter found in the soil, including plant and animal materials that are in the process of decomposition.) It strengthens the capacity of soils to retain water and nutrients, supports structure that promotes drainage and aeration, and helps minimize the loss of topsoil through erosion.
For years, policymakers have emphasized the role of soil organic matter in a series of programs, including the “4 per 1,000” initiative of the Soils for Food Security — which emerged from the COP21 negotiations — and the U.S.’s “Framework for a Federal Strategic Plan for Soil Science.”
And yet when it comes to its role in promoting crop production, there’s been a surprising dearth of quantitative evidence, Bradford says. For Bradford, this gap in knowledge has been a nagging concern for nearly a decade; a 2010 National Research Council report on sustainable agriculture described organic matter as the cornerstone of most sustainability and soil quality initiatives, he recalls, yet offered no information on how much was actually needed to increase crop yields and reduce fertilizer application.
he solar panels in the fields at the University of Massachusetts Crop Research and Education Center don’t look like what most of us have come to expect. Instead of hunkering close to the earth, they’re mounted seven feet off the ground, with ample room for farmers or cows to wander underneath. Panels are separated by two- and three-foot gaps, instead of clustering tightly together. Light streams through these spaces and, underneath, rows of leafy kale and Brussels sprouts replace the typical bare earth or grass.
This unusual arrangement is one of the first examples of a dual-use solar installation—sometimes called agrivoltaics. It’s a photovoltaic array that’s raised far enough off the ground and spaced in such a way that some crops can still grow around and beneath the panels. The goal is to help farmers diversify their income through renewable energy generation, while keeping land in agricultural use and reducing greenhouse gas emissions….
Policymakers and investors have perceived securing soil organic carbon as too difficult, with uncertain returns. But new technical, policy and financial opportunities offer hope for rapid progress.
Sonja Vermeulen, Deborah Bossio, Johannes Lehmann, Paul Luu, Keith Paustian, Christopher Webb, Flore Augé, Imelda Bacudo, Tobias Baedeker, Tanja Havemann, Ceris Jones, Richard King, Matthew Reddy, Ishmael Sunga, Moritz Von Unger and Matthew Warnken. Nature Sustainability | VOL 2 | JANUARY 2019 | 2–4 | www.nature.com/natsustain Read full NATURE article here and Nature4Climate article here (and below)
“It’s too hard and too uncertain,” has long been the response of policymakers and investors in response to working on ways to conserve and improve carbon in soil. But, recent new momentum summarised in a paper in Nature Sustainability and authored by actors from government, science and the private sector offers hope in the form of technical, policy and ﬁnancial opportunities for rapid progress.
Building soil organic carbon helps water cycling, agricultural productivity, as well as climate change mitigation and adaptation. The amount of soil carbon globally is triple that of the atmosphere, making soil a useful tool for combatting climate change. A new global analysis … shows that building soil organic carbon on all corn and wheat lands could close the yield gaps for those crops by between 1/3 and 2/3 while also minimizing dependence on synthetic fertilizers.
“Momentum for action on soil organic carbon is indeed growing in political, financial and technical circles to address multiple sustainability goals, but not nearly fast enough.” says Deborah Bossio, Lead Soil Scientist at The Nature Conservancy and co-author of the paper published in Nature Sustainability. Authors of the paper conclude that ‘a clear focus on early wins and on continued collaboration will lay the ground for gains in soil organic carbon at scale within an urgent timeframe.’
Under the UN Climate Convention (UNFCCC) only eight countries include targets for soil organic carbon within their intended mitigation options – (Armenia, Burkina Faso, China, Japan, Malawi, Namibia, Uruguay and Zambia). That said, a few have policies that support stronger action, ranging from Canada, which recognizes the potential of soil organic carbon under conserved forests and wetlands, to Bhutan, with its sustainable soil policy.
Pioneering initiatives – both regulatory and voluntary – at national and sub-national levels, also provide evidence of economic viability and rapid results at the local level. Australia and California are examples of early adopters of market-based approaches to raising soil organic carbon. Australia’s Carbon Farming Initiative, a legislated voluntary offsets scheme implemented by the Emission Reduction Fund, has awarded contracts with an approximate value of A$200 million to landholders and farmers to earn carbon credits from soil organic carbon projects on degraded land, supporting a wide range of activities from rotational grazing to reduced tillage.
In the private sector, a growing number of companies are also including soil organic carbon within their set of options to build resilience and long-term profitability of agricultural value chains. Danone, Mars, Bayer, Coca Cola, Fonterra, Diageo and Olam are multinational examples.
“We need a new mindset,” said Deborah Bossio. “We need to give up on the idea that it’s all too hard. To combat climate change and to produce healthy diets, we need every tool in the toolbox. We might not think about soil all the time, but boy we notice it when it’s gone.”
Marc G. Kramer, Oliver A. Chadwick. Climate-driven thresholds in reactive mineral retention of soil carbon at the global scale. Nature Climate Change, 2018; 8 (12): 1104 DOI: 10.1038/s41558-018-0341-4
One answer to our greenhouse gas challenges may be right under our feet: Soil scientists have found that minerals in soil can hold on to a significant amount of carbon pulled from the atmosphere. It’s a mechanism that could potentially be exploited as the world tries to shift its carbon economy. …
… Wetter climates are more conducive to formation of minerals that are effective at storing carbon, therefore much of the Earth’s estimated 600 billion metric tons of soil-bound carbon is found in the wet forests and tropical zones. Arid places, meanwhile, tend to have a “negative water balance” and can thus store far less organic carbon. According to Chadwick, the findings suggest that even a small, strategic change in the water balance could drive greater carbon storage.
… There is still a lot to investigate and several hurdles to overcome as soil scientists everywhere consider ways to tip the balance of the Earth’s soil from carbon source to carbon sink, but according to these researchers, understanding this relatively little-known but highly significant carbon storage pathway is a start.
Long-term removal of grazing from semiarid grassland ecosystems in the western North American Great Plains does not enhance long-term SOC sequestration.
Justin D. Derner, David J. Augustine, Douglas A. Frank. Ecosystems (2018). https://doi.org/10.1007/s10021-018-0324-3
Considerable uncertainty remains regarding grazing-induced
influences on soil organic carbon (SOC) sequestration in semiarid grassland
ecosystems due to three important complications associated with studying such
effects: (1) Ecologically meaningful shifts in SOC pools attributable to
grazing are difficult to detect relative to inherently large grassland SOC
pools, (2) a lack of baseline (pre-treatment) data, and (3) frequent lack of or
limited replication of long-term grazing manipulations. SOC sequestration rates
were determined in 74-year-old grazing exclosures and paired moderately grazed
sites, established across a soil texture gradient, in the western North
American shortgrass steppe in northeastern Colorado. We sampled soils (0–20 cm)
from 12 exclosures and paired grazed sites to measure SOC concentration and
soil radiocarbon D14C (&); the latter allowed us to determine turnover of
the SOC pool over a 7-decade period in the presence versus the absence of
grazing. Removal of grazing for more than 7 decades substantially altered plant
community composition but did not affect total soil C, SOC, soil D14C, SOC
turnover rate, or total soil N. Grazing effect also did not interact with soil
texture to influence any of those soil properties. Soil texture (silt + clay
content) did influence total soil C and SOC, and total soil N, but not D14C or
SOC turnover. Results provide evidence that long-term removal of grazing from
semiarid grassland ecosystems in the western North American Great Plains does
not enhance long-term SOC sequestration, despite changes in the relative
dominance of C3 versus C4 grasses.
Soils rich in organic carbon are associated with enhanced agricultural productivity, water cycling, biodiversity and climate change adaptation and mitigation. But despite the important role they can play in fighting climate change, to date soils have largely been missing from carbon markets.
There are signs that the future may be more promising. This study assesses the specific situation of soil carbon—its position in climate policymaking, the specific challenges, and the opportunities for intervention. It does so to explore to what extent carbon project finance tools can help advance the ability of soil carbon to make a meaningful contribution to climate change mitigation, providing multiple co-benefits. By taking the voluntary market as the lens, it also serves to inform the wider fate and utility of land sector carbon projects within the evolving political framework of the Paris Agreement.
Deborah Bossio, TNC, was a consultant on this project.