Food security will be increasingly challenged by climate change, natural resource degradation, and population growth. Wheat yields, in particular, have already stagnated in many regions and will be further affected by warming temperatures. Despite these challenges, wheat yields can be increased by improving management practices in regions with existing yield gaps. To identify the magnitude and causes of current yield gaps in India, one of the largest wheat producers globally, we produced 30 meter resolution yield maps from 2001 to 2015 across the Indo-Gangetic Plains (IGP), the nation's main wheat belt. Yield maps were derived using a new method that translates satellite vegetation indices to yield estimates using crop model simulations, bypassing the need for ground calibration data. This is one of the first attempts to apply this method to a smallholder agriculture system, where ground calibration data are rarely available. We find that yields can be increased by 11% on average and up to 32% in the eastern IGP by improving management to current best practices within a given district. Additionally, if current best practices from the highest-yielding state of Punjab are implemented in the eastern IGP, yields could increase by almost 110%. Considering the factors that most influence yields, later sow dates and warmer temperatures are most associated with low yields across the IGP. This suggests that strategies to reduce the negative effects of heat stress, like earlier sowing and planting heat-tolerant wheat varieties, are critical to increasing wheat yields in this globally-important agricultural region.
The gap between yield potential and average farmers’ yield measures the capacity for yield improvement with current technology. The North China Plain (NCP) is a major maize producing region of China, and improving maize yield of NCP is essential to food security of the country. Some previous studies have found a substantial maize yield gap in this region (∼100% of average yields), whereas others have reported much smaller gaps. This study used remote sensing estimated yield at 30-m resolution to quantify county level yield distributions, and then used these distributions to calculate yield gaps and the persistence level of yield for 76 counties in NCP. The average yield was 8.66 t/ha across county years, and the averaged county-level yield gap, as measured by the difference between the top 10 percentile of yields and the average yield of each county, was 0.76 t/ha, or 8.7% of the average yield. When measured as the difference between maximum and average yields in each county, the estimated gap increased to an average of 31%. We also evaluated the persistence level of farmers’ yield performance, as an indicator of how much gap might be reduced by propagating agronomic practices of the highest yielding farmers. The average of yield gap persistence was 25.9% of the average yield gap, or 2.3% of average yield with a range from 0.4% to 5.3% across counties. The distance to major rivers was identified as one factor with a significant effect on yield. Nevertheless, there was tremendous spatial heterogeneity in yield persistence level across NCP, and further analysis within individual counties is required to better prioritize means to shrink the yield gap.
An interview with authors of the “The Tropical Oil Crop Revolution” predicts the future of soy and palm oil booms by examining the past and present.
Used in everything from food to fuel, soybean and palm oil have seen production rates skyrocket in the past 20 years. Controversy surrounds the planting of oil crops – cultivated primarily in Southeast Asia and South America – as they are often grown on deforested lands and rely on large farmers and agribusiness rather than smallholders. “The Tropical Oil Crop Revolution: Food, Feed, Fuel, and Forests,” a new book co-authored by Stanford University researchers, examines the economic, social and environmental impacts of the oil crop revolution, and explores how to develop a more sustainable future.
Derek Byerlee, visiting fellow at Stanford’s Center on Food Security and the Environment (FSE), FSE Fellow Walter P. Falcon, and FSE Director Rosamond L. Naylor recently discussed some of their book’s key ideas.
Q: What are the key similarities and differences between the rise of oil crops and the 1965-85 green revolution?
A: From 1990 to 2010, world production of soybean grew by 220 percent and production of palm oil by 300 percent. Like the green revolution for cereal crops, this recent revolution involves two crops – oil palm and soybeans – that dramatically expanded shares in their respective crop subsector – oil crops.
The oil crop revolution differs from its predecessor, the green revolution of rice and wheat, in its mode of expansion. The green revolution embraced tens of millions of producers across many countries, especially where irrigation was available. The oil crop revolution was highly concentrated in a few countries and almost entirely in rainfed areas. Unlike the green revolution, which was spurred on by rapid yield gains, the force behind the oil crop revolution was expansion of crop area.
Q: What are some ways to improve oil palm sustainability?
A: A lot of faith has been put on certification and private standards and commitments. However, without effective land and forest governance, it will be very difficult for the private sector to operate. The state at both national and local levels will need greatly improved and more transparent systems starting from land and forest tenure laws, information systems, civil service capacity and judicial and redress systems.
Q:How will the future of oil crops differ from the past?
A: By 2050, we predict demand for oil crops to drop by as much as two-thirds. Demand for biofuel feedstocks cannot maintain the rapid pace of the past decade. Vegetable oils used for food will also grow more slowly. In Asia, population growth will slow and the effects of rising incomes will diminish as consumers in middle-income countries reach high levels of vegetable oil consumption.
The biggest wild card in terms of supply is land availability. Africa has the most land available, however access to clear property rights are often difficult due to “customary rights” to the land. Soybean, a new crop in much of Africa, will increase along with oil palm. We believe the area covered by oil crops does not have to expand greatly; rather, intensification of existing crop land and a modest expansion in area can meet demand. Steady progress is possible through genetic gains in yield. Sufficient degraded land is available for area expansion, provided land governance and incentive systems are developed to steer the expansion onto degraded lands.
Q: How has development of the biodiesel industry affected tropical vegetable oils in the past 25 years, and how will it shape the sector going forward?
A: Before the turn of the 21st century, few analysts predicted that biodiesel would play a major role in boosting global vegetable oil demand and prices. As it turns out, the expansion of biodiesel markets has been responsible for roughly half of the increase in vegetable oil consumption since 2013. Global biodiesel production more than doubled between 2007 and 2013. By some estimates, it could grow another 50 percent by 2025.
National energy policies continue to play a dominant role in the profitability of the biodiesel industry. The growing response of biofuel policies to low agricultural commodity prices is an important factor that is bound to keep biodiesel in the transportation fuel mix. This is true at least in countries that have strong interests oil crops, such as Indonesia, Malaysia, and Colombia in the case of oil palm, and the U.S., Brazil, and Argentina in the case of soybeans. Without policies mandating the use of biodiesel in fuel mixes, or incentivizing its use, the industry might fade away.
Q: What do you believe is the biggest takeaway from your research?
A: We are cautiously optimistic that the future expansion of the oil crop sector can be managed more sustainably. The predicted slowing of demand and land requirements will reduce pressure on native ecosystems. Several signs point to convergence among global consumers, private business, civil society, and local governments in finding ways to minimize the trade-offs between economic benefits and social and environmental costs.
Derek Byerlee, is an Adjunct Professor in the Global Human Development Program at Georgetown University and Editor-in-Chief of the Global Food Security journal. Walter P. Falcon is the Farnsworth Professor of International Agricultural Policy (Emeritus) at Stanford, senior fellow with the Freeman Spogli Institute for International Studies and the Stanford Woods Institute for the Environment. Rosamond L. Naylor is the William Wrigley Professor in Earth Science and Professor of Economics (by courtesy) and Gloria and Richard Kushel Director, at the Center on Food Security and the Environment Stanford.
In a shack that now sits below sea level, a mother in Bangladesh struggles to grow vegetables in soil inundated by salt water. In Malawi, a toddler joins thousands of other children perishing from drought-induced malnutrition. And in China, more than one million people died from air pollution in 2012 alone.
Around the world, climate change is already having an effect on human health.
In a recent paper, Katherine Burke and Michele Barry from the Stanford Center for Innovation in Global Health, along with former Wellesley College President Diana Walsh, described climate change as “the ultimate global health crisis.” They offered recommendations to the new United States president to address the urgently arising health risks associated with climate change.
Bangladeshi children make their way through flood waters.
The authors, along with Stanford researchers Marshall Burke, Eran Bendavid and Amy Pickering who also study climate change, are concerned by how little has been done to mitigate its effects on health.
There is still time to ease — though not eliminate — the worst effects on health, but as the average global temperature continues to creep upward, time appears to be running short.
“I think we are at a critical point right now in terms of mitigating the effects of climate change on health,” said Amy Pickering, a research engineer at the Woods Institute for the Environment. “And I don’t think that’s a priority of the new administration at all.”
Health effects of climate change
Even in countries like the United States that are well-equipped to adapt to climate change, health impacts will be significant.
“Extremes of temperature have a very observable direct effect,” said Eran Bendavid, an assistant professor of medicine and Stanford Health Policy core faculty member.
“We see mortality rates increase when temperatures are very low, and especially when they are very high.”
Bendavid also has seen air pollutants cause respiratory problems in people from Beijing to Los Angeles to villages in Sub-Saharan Africa.
“Hotter temperatures make it such that particulate matter and dust and pollutants stick around longer,” he said.
In addition to respiratory issues, air pollution can have long-term cognitive effects. A study in Chile found that children who are exposed to high amounts of air pollution in utero score lower on math tests by the fourth grade.
“I think we’re only starting to understand the true costs of dirty air,” said Marshall Burke. “Even short-term exposure to low levels can have life-long effects.”
Low-income countries like Bangladesh already suffer widespread, direct health effects from rising sea levels. Salt water flooding has crept through homes and crops, threatening food sources and drinking water for millions of people.
“I think that flooding is one of the most pressing issues in low-income and densely populated countries,” said Pickering. “There’s no infrastructure there to handle it.”
Standing water left over from flooding is also a breeding ground for diseases like cholera, diarrhea and mosquito-borne illnesses, all of which are likely to become more prevalent as the planet warms.
On the flip side, many regions of Sub-Saharan Africa — where clean water is already hard to access — are likely to experience severe droughts. The United Nations warned last year that more than 36 million people across southern and eastern Africa face hunger due to drought and record-high temperatures.
Residents may have to walk farther to find water, and local sources could become contaminated more easily. Pickering fears that losing access to nearby, clean water will make maintaining proper hygiene and growing nutritious foods a challenge.
Climate change will affect health in all sectors of society.
All of these effects and more can also damage mental health, said Katherine Burke and her colleagues in their paper. The aftermath of extreme weather events and the hardships of living in long-term drought or flood can cause anxiety, depression, grief and trauma.
Climate change will affect health in every sector of society, but as Katherine Burke and her colleagues said, “….climate disruption is inflicting the greatest suffering on those least responsible for causing it, least equipped to adapt, least able to resist the powerful forces of the status quo.
“If we fail to act now,” they said, “the survival of our species may hang in the balance.”
What can the new administration do to ease health effects?
If the Paris Agreement’s emissions standards are met, scientists predict that the world’s temperature will increase about 2.7 degrees Celsius – still significant but less hazardous than the 4-degree increase projected from current emissions.
The United States plays a critical role in the Paris Agreement. Apart from the significance of cutting its own emissions, failing to live up to its end of the bargain — as the Trump administration has suggested — could have a significant impact on the morale of the other countries involved.
“The reason that Paris is going to work is because we’re in this together,” said Marshall Burke. “If you don’t meet your target, you’re going to be publicly shamed.”
The Trump administration has also discussed repealing the Clean Power Plan, Obama-era legislation to decrease the use of coal, which has been shown to contribute to respiratory disease.
“Withdrawing from either of those will likely have negative short- and long-run health impacts, both in the U.S. and abroad,” said Marshall Burke.
Scott Pruitt, who was confirmed today as the head of the Environmental Protection Agency (EPA), is expected to carry out Trump’s promise to dismantle environment regulations.
Despite the Trump administration’s apparent doubts about climate change, a few prominent Republicans do support addressing its effects.
Secretary of State Rex Tillerson, the former chairman and CEO of Exxon Mobile, supports a carbon tax, which would create a financial incentive to turn to renewable energy sources. He also has expressed support for the Paris Agreement. It is possible that as secretary of state, Tillerson could help maintain U.S. obligations from the Paris Agreement, though it is far from certain whether he would choose to do so or how Trump would react.
More promising is a recent proposal from the Climate Leadership Council. Authored by eight leading Republicans — including two former secretaries of state, two former secretaries of the treasury and Rob Walton, Walmart’s former chairman of the board — the plan seeks to reduce emissions considerably through a carbon dividends plan.
Already an issue, malnutrition will increase with droughts in Sub-Saharan Africa.
Their proposal would gradually increase taxes on carbon emissions but would return the proceeds directly to the American people. Americans would receive a regular check with their portion of the proceeds, similar to receiving a social security check. According to the authors, 70 percent of Americans would come out ahead financially, keeping the tax from being a burden on low- and middle-income Americans while still incentivizing lower emissions.
“A tax on carbon is exactly what we need to provide the right incentives and induce the sort of technological and infrastructure change needed to reduce long-term emissions,” said Marshall Burke.
Pickering added, “This policy is a ray of hope for meaningful action on climate.”
It remains to be seen whether the new administration and congress would consider such a program.
What can academics do to help?
Meanwhile, academics can promote health by researching the effects of climate change and finding ways to adapt to them.
“I think it’s fascinating that there’s just so little data right now on how climate change is going to impact health,” said Pickering.
Studying the effects of warming on the world challenges traditional methods of research.
“You can’t create any sort of experiment,” said Bendavid. “There’s only one climate and one planet.”
The scholars agree that interdisciplinary study is a critical part of adapting to climate change and that more research is needed.
“If ever there was an issue worthy of a leader’s best effort, this is the moment, this is the issue,” said Katherine Burke and her colleagues. “Time is short, but it may not be too late to make all the difference.”
China’s 13th Five-Year Plan, launched in March 2016, provides a sound policy platform for the protection of marine ecosystems and the restoration of capture fisheries within China’s exclusive economic zone. What distinguishes China among many other countries striving for marine fisheries reform is its size—accounting for almost one-fifth of global catch volume—and the unique cultural context of its economic and resource management. In this paper, we trace the history of Chinese government priorities, policies, and outcomes related to marine fisheries since the 1978 Economic Reform, and examine how the current leadership’s agenda for “ecological civilization” could successfully transform marine resource management in the coming years. We show how China, like many other countries, has experienced a decline in the average trophic level of its capture fisheries during the past few decades, and how its policy design, implementation, and enforcement have influenced the status of its wild fish stocks. To reverse the trend in declining fish stocks, the government is introducing a series of new programs for sustainable fisheries and aquaculture, with greater traceability and accountability in marine resource management and area controls on coastal development. As impressive as these new plans are on paper, we conclude that serious institutional reforms will be needed to achieve a true paradigm shift in marine fisheries management in China. In particular, we recommend new institutions for science-based fisheries management, secure fishing access, policy consistency across provinces, educational programs for fisheries managers, and increasing public access to scientific data.
The future trajectory of crop yields in the United States will influence food supply and land use worldwide. We examine maize and soybean yields for 2000–2015 in the Midwestern U.S. using a new satellite-based dataset on crop yields at 30m resolution. We quantify heterogeneity both within and between fields, and find that the difference between average and top yielding fields is typically below 30% for both maize and soybean, as expected in advanced agricultural regions. In most counties, within-field heterogeneity is at least half as large as overall heterogeneity, illustrating the importance of non-management factors such as soil and landscape position. Surprisingly, we find that yield heterogeneity is rising in maize, both between and within fields, with average yield differences between the best and worst soils more than doubling since 2000. Heterogeneity trends were insignificant for soybean. The findings are consistent both with recent adoption of precision agriculture technologies and with recent trends toward denser sowing in maize, which disproportionately raise yields on better soils. The results imply that yield gains in the region are increasingly derived from the more productive land, and that sub-field precision management of nutrients and other inputs is increasingly warranted.
Pamela Ronald
Tomorrow’s Table: Ecologically-based Farming, Plant Genetics and the Future of Food
Professor in the Department of Plant Pathology and the Genome Center
University of California, Davis
This Global Food Security Strategy presents an integrated whole-of-government strategy and agency-specific implementation plans as required by the Global Food Security Act of 2016 (GFSA).
"Right now, the world is closer than ever before to ending global hunger, undernutrition, and extreme poverty, but significant challenges and opportunities remain, including urbanization, gender inequality, instability and conflict, the effects of a changing climate, and environmental degradation. Despite our collective progress in global food security and nutrition over recent years, a projected 702 million people still live in extreme poverty, nearly 800 million people around the world are chronically undernourished, and 159 million children under five are stunted. Food security is not just an economic and humanitarian issue; it is also a matter of security, as growing concentrations of poverty and hunger leave countries and communities vulnerable to increased instability, conflict, and violence." From the USAID Oct. 3 release.
You can read more and download the pdf of the Global Food Security Strategy at the USAID website.
Bangladeshi children make their way through flood waters.
Climate change will affect health in all sectors of society.
Already an issue, malnutrition will increase with droughts in Sub-Saharan Africa.
