Latest National Climate Assessment
Says Inaction Poses Grim Outlook
The latest report on climate change issued by a collaboration of 13 federal departments and agencies – including the Departments of Agriculture and Interior, as well as EPA – forecasts extremely hard times for the U.S. agriculture and forest sectors if no action is taken immediately to stem the challenges that come with volatile weather and related conditions.
The Trump administration released the Fourth National Climate Assessment Report, Volume II, which focuses on impacts, risks and adaptation in the United States. The latest report represents the work of more than 300 government scientists and was produced by the U.S. Global Change Research Program under the guidance of a 60-member federal advisory committee. The first volume of the quadrennially produced assessment was released last year.
“Climate change presents numerous challenges to sustaining and enhancing crop productivity, livestock health, and the economic vitality of rural communities,” says the latest report, released the day after Thanksgiving. “While some regions (such as the Northern Great Plains) may see conditions conducive to expanded or alternative crop productivity over the next few decades, overall, yields from major U.S. crops are expected to decline as a consequence of increases in temperatures and possibly changes in water availability, soil erosion, and disease and pest outbreaks.”
The assessment says increases in temperatures during the growing season in the Midwest are projected to be the largest contributing factor to declines in the productivity of U.S. agriculture, while a rise in extreme heat conditions are projected to result in growing heat stress for livestock, resulting in “large economic losses for producers.”
In an interview with The Washington Post last week, President Trump, who has long dismissed warnings about climate change – last August, he dismissed a climate change advisory committee charged with guiding policy makers on the findings of the assessments – said he was skeptical of the latest report’s projections.
“One of the problems that a lot of people like myself, we have very high levels of intelligence but we’re not necessarily such believers,” he said.
Others in the administration, including White House spokesperson Sarah Huckabee Sanders, said the assessments conclusions were based solely on worst-case scenarios.
Many scientists who worked on the report disputed the “worst-case” assertion, responding that the assessment’s conclusions were reached after modeling all levels of climate event severity.
SfL underscored the importance of the assessment in a blog posted last week that stated: “There is no way to sugarcoat or downplay the outlook which the report forecasts. For agriculture and forestry, it can be summed up in one word: grim.”
The report shares four key messages for the agricultural sector, with each citing the existing and future challenges, accompanied by ongoing and potential solutions:
Key Message 1- Reduced Agricultural Productivity
Food and forage production will decline in regions experiencing increased frequency and duration of drought. Shifting precipitation patterns, when associated with high temperatures, will intensify wildfires that reduce forage on rangelands, accelerate the depletion of water supplies for irrigation, and expand the distribution and incidence of pests and diseases for crops and livestock. Modern breeding approaches and the use of novel genes from crop wild relatives are being employed to develop higher-yielding, stress-tolerant crops.
Key Message 2- Degradation of Soil and Water Resources
The degradation of critical soil and water resources will expand as extreme precipitation events increase across our agricultural landscape. Sustainable crop production is threatened by excessive runoff, leaching, and flooding, which results in soil erosion, degraded water quality in lakes and streams, and damage to rural community infrastructure. Management practices to restore soil structure and the hydrologic function of landscapes are essential for improving resilience to these challenges.
Key Message 3- Health Challenges to Rural Populations and Livestock
Challenges to human and livestock health are growing due to the increased frequency and intensity of high temperature extremes. Extreme heat conditions contribute to heat exhaustion, heatstroke, and heart attacks in humans. Heat stress in livestock results in large economic losses for producers. Expanded health services in rural areas, heat-tolerant livestock, and improved design of confined animal housing are all important advances to minimize these challenges.
Key Message 4- Vulnerability and Adaptive Capacity of Rural Communities
Residents in rural communities often have limited capacity to respond to climate change impacts, due to poverty and limitations in community resources. Communication, transportation, water, and sanitary infrastructure are vulnerable to disruption from climate stressors. Achieving social resilience to these challenges would require increases in local capacity to make adaptive improvements in shared community resources.
The National Oceanic and Atmospheric Administration (NOAA) recorded 16 weather and climate disasters that caused one billion dollars or more in property damage in 2017, from freezes and hail, to fires and flooding.
In the first six months of 2018, NOAA reports that the U.S. experienced six disasters resulting in damages of $1 billion or more. The agency says more recent disasters are sure to exceed that mark as well.
New Study Reveals Natural Solutions
Can Stem GHG Emissions
Restoring U.S. lands and coastal wetlands could have a much bigger role in reducing global warming than previously thought, according to the most comprehensive national assessment to date of how greenhouse gas (GHG) emissions can be reduced and stored in farmland, grasslands, forests and wetlands.
The peer-reviewed study in Science Advances from The Nature Conservancy, a global land conservation organization, and 21 institutional partners found that nature’s contribution could equal 21 percent of the nation’s current net annual emissions, by adjusting 21 natural management practices to increase carbon storage and avoid greenhouse emissions. The study is the first to include the climate benefits of coastal wetlands and grasslands in a comprehensive mix along with forests and agriculture.
In October the Intergovernmental Panel on Climate Change special report called for global action immediately to limit warming to 1.5 degrees Centigrade (approximately 3 degrees Fahrenheit) to avoid the most damaging climate change impacts. The new study highlights how, and which, natural solutions in the United States offer the most promise to help limit temperatures below that 3 degrees F goal.
“One of America’s greatest assets is its land,” said Joe Fargione, director of sciency for the conservancy and the study’s lead author.”Through changes in management, along with protecting and restoring natural lands, we demonstrated we could reduce carbon pollution and filter water, enhance fish and wildlife habitat, and have better soil health to grow our food – all at the same time. Nature offers us a simple, cost-effective way to help fight global warming. In combination with transitioning to zero carbon energy production, natural climate solutions can help protect our climate for future generations.”
“An ounce of prevention is worth a pound of cure, so we should reduce carbon pollution where we can, ” said Lynn Scarlett, chief external affairs officer for The Nature Conservancy and former deputy secretary of the Department of the Interior, speaking to practical elements of the study’s findings. “But we also need to put natural solutions to work as a tool to insulate ourselves from global warming. This study provides good news that making investments in nature will make a big difference, while offering the potential for new revenue to farmers, ranchers, foresters, and coastal communities at the same time.”
Existing croplands have an important role to play, the study finds. Farmers can optimize their nutrient application, saving money and avoiding emissions of nitrous oxide, a potent greenhouse gas. Farmers can also plant cover crops, which suck carbon out the atmosphere and return it to the soil during times of the year when fields would normally be bare.
“Farmers are some of our best land stewards,” said Chris Adamo, vice president Federal and Industry Affairs at Danone North America, a firm that is partnering with farms across the country to find climate solutions through a soil health initiative. “Improved nutrient management, cover crops, and crop rotations are examples of practices that can help reduce GHG emissions and over time improve a farm’s bottom-line.
“Farmers and the food industry depend on a predictable climate, so it’s important to work together to reduce the risks of climate change.” He said.
Of the 21 natural solutions analyzed, increased reforestation (the planting of trees) emerged as the largest means to achieve greater carbon storage, equivalent to eliminating the emissions of 65 million passenger cars. Other high-performing forest solutions include allowing longer periods between timber harvest to increase carbon storage; increasing controlled burns and strategic thinning in forests to reduce the risk of megafire; and avoided loss of forests from urban sprawl.
The study identified a maximum of 156 million acres that could be reforested, 304 million acres where forest harvest rotations could be extended, and at least 42 million additional acres of forests that would benefit from fire risk reduction treatments. In addition, almost a million acres of forest are being converted to non-forest habitat a year, largely due to suburban and exurban expansion, which could be addressed through better land use planning. The study also finds that urban reforestation can add important carbon storage benefits.
“Planting trees and improving the health of existing forests will be a deciding factor in whether we are able to get ahead of the climate curve,” said Jad Daley, CEO of American Forests. “This breakthrough analysis clarifies the highest impact actions for keeping our forests as a growing and resilient carbon sink and the potential scale of climate benefit.”
Grasslands, which are underappreciated for their carbon storage opportunity, are being lost at a rate of over one million acres per year. When grassland is converted to cropland and other uses, about 28 percent of the carbon in the top meter of soil is released to the atmosphere. The trend could be reversed by re-enrolling 13 million acres of marginal cropland in conservation programs and restoring them to provide habitat and storage of carbon in the soil, the study says.
Natural solutions can be found under water as well. An estimated 27 percent of tidal wetlands have been disconnected from the ocean, increasing the release of methane. Reconnecting tidal wetlands to the ocean virtually eliminates those methane emissions, and also restores fish habitat important for coastal communities.
The study says that in addition to benefiting personal enjoyment, healthier water, air, wildlife, and soil, many natural climate solutions are quite affordable. As states and the federal government evaluate rules and markets for greenhouse gas emissions, the low-cost reductions from natural solutions offer the United States a powerful tool to address a warming planet.
Promoting Climate-Friendly Ag Can Benefit
Farmers, Rural U.S., Environment
The federal government can help give farmers the tools they need to make their farms more climate resilient – while turning agriculture into a net carbon sink – through an ambitious research agenda, two attorneys state in an article in the American Bar Association journal, Natural Resources and Environment.
Peter Lehner, senior attorney and director of the Sustainable Food and Farming program at Earthjustice, and Nathan Rosenberg, an adjunct professor at the University of Arkansas School of Law, say policy makers have given little consideration to agriculture’s growing vulnerability to climate change, nor have they reckoned with the sector’s substantial contribution to U.S. greenhouse gas (GHG) emissions.
The omission, they note, comes despite the fact that agriculture covers 61 percent of the contiguous United States and is responsible for 8 percent of the nation’s greenhouse gas (GHG) emission. Furthermore, many rural communities depend on a thriving agriculture sector and society depends on the production of affordable nutritious food.
“Instead of boosting support for agricultural research, however, the public sector has started to retreat from it – particularly research that doesn’t match the priorities of agribusiness,” Lehner and Rosenberg write.
They note that President Trump’s proposed budget for fiscal year 2019 would cut into publicly funded agricultural research even further.
“While public support for agricultural research has fallen rapidly, reliance on industry funding has increased, influencing researchers’ priorities and agendas,” they say. “The funding share devoted to diversified systems, which offer the greatest societal and climate benefits, will remain meager without robust public support.”
The two attorneys note that states and nonprofit organizations have started to develop compelling models for supporting climate-friendly agricultural systems, helping to counteract the agrochemical industry’s financial leverage. Nonetheless, they say, the federal government has a critical role to play in developing and disseminating climate-friendly agricultural practices.
“In light of the risks presented by climate change (and other environmental stresses), and the potential for agriculture to reduce these risks, Congress should, at a minimum, increase the [USDA’s] research budget from $2 billion to over $5 billion,” they write. The boost would increase relative funding for research from less than 2 percent of USDA’s budget to about 4 percent, which was its average share between 1940 and 1980, a period when agricultural productivity rose quickly, in large part due to research funded by USDA.
While significant, this increase represents only a fraction of the roughly $20 billion spent annually on crop insurance and other subsidies. If focused on climate-related research, however, the additional funding would allow USDA and USDA-funded researchers to develop the tools, monitoring and measuring protocols, crops, breeds, and practices necessary for climate-friendly farming to thrive.
Relatively little of the $2 billion USDA currently spends annually on agricultural research goes to support climate- friendly practices, the authors state, asserting that the funds should be redirected to support “carbon farming,” a suite of climate-friendly practices that recognize agriculture is capable of producing a number of public goods in addition to agricultural commodities, including an astounding capacity for carbon sequestration.
They note that many agricultural production systems, especially perennial agriculture and agroforestry, not only reduce GHG emissions, but also demonstrate high levels of sequestration. They cite as an example the side-by-side planting of annual crops with trees in adjacent rows, a practice called alley cropping, which could reduce net U.S. agricultural emissions by 160 to 345 million metric tons of carbon dioxide equivalent alone, tantamount to taking 34 to 74 million vehicles off the road.
“Considering their sector’s vulnerability to changing weather patterns, farmers also have a strong interest in mitigating climate change,” write Lehner and Rosenberg. “Climate change is already resulting in catastrophic crop losses due to drought, heat waves, heavy downpours, floods and hurricanes, among other extreme weather events, and this will only intensify as temperatures rise.”
However, many practices that reduce GHG emissions and increase soil carbon levels also reduce costs, increase soil health and fertility, and make farms and ranches more resilient to climate change. They can increase yields in the face of the emerging challenges, they write.
The attorneys say that if USDA is to be an effective force for decarbonizing agriculture, its research, education, and extension programs will need to work in tandem. They cite “step forward” taken by USDA in 2014 that facilitated interagency collaboration on climate-related projects with the creation of 10 regional “Climate Hubs.” The hubs are designed to support applied research, translate climate-related research into tools and methods for outreach and education, and coordinate USDA’s climate-related activities in each region. The hubs also work with the extension system, universities, other government agencies and the private sector to help promote agricultural practices informed by climate science. While their future is uncertain under the current administration, climate hubs provide a promising model for coordinating climate-related, the authors say.
Research Shows Farmer Adjustments
Offset Climate Change Impacts in Corn Production
Recent research published in Proceedings of the National Academy of Sciences on historical yields across the U.S. Corn Belt suggests that a continuation of the historical yield trend will depend on a stable climate and continued farmer adjustments.
The research was done in response to the widespread concern that climate change will have a strong negative effect on crop yields.
Ethan Butler, postdoctoral associate in the Department of Forest Resources in the College of Food, Agricultural and Natural Resource Sciences at the University of Minnesota, Butler and colleagues from Harvard University and the University of California, Irvine, analyzed how both climate and management have influenced the increase in yields.
Overall, the research shows farmers have adapted to historical climate change. The combination of changes in climate, primarily cooling of the hottest temperatures, and farmer adjustments, including earlier planting and planting longer maturing varieties, increased maize yield trends 28 percent since 1981.
“We wanted to add the farmer into the picture of how climate change will affect crops,” said Butler. “Sometimes, it feels like climate change is a juggernaut that is going to trample our way of life. In this research we’ve shown that farmers have already made adjustments to better align their planting practices with historical climate changes, and we hope this can be a guide to changes in the future.”
Butler and the research team used a statistical model to study how rainfed maize yields reported by the U.S. Department of Agriculture (USDA) are affected by temperature using three crop development phases: vegetative, early grain filling and late grain filling. They found that planting is occurring earlier and that the late grain filling phase lasts longer. At the same time, the hottest temperatures have cooled. The earlier planting and longer grain filling are primarily associated with management decisions, while the cooling of hot temperatures appears to be an unintended benefit of widespread planting of high-yielding modern cultivars.
“Among farmers’ biggest decisions are what they plant and when they plant it,” said Butler. “We are seeing that farmers are planting earlier – not only because they have hardier seeds and better planting equipment – but also because it’s getting warmer sooner.”
The research also suggests the adjustments farmers have made have increased yields more than they would have in the absence of the historical changes in climate.
However, in the Corn Belt, this means accentuating a surprisingly beneficial climate trend rather than reducing damages from a harmful change. This implies farmers have proven adept at adjusting to environmental changes, but that these benefits may evaporate in a warming climate.
It is unclear whether these historical patterns of adaptation will be maintained in a hotter environment. But farmer decisions must be considered in future analyses of how crop yields will be affected by a changed climate.
The team hopes that by studying farmer adaptations, which have received relatively little attention, they will help to improve concrete actions that can be taken to reduce damages from a hotter world in the future.
The research was funded by the Packard Foundation, USDA and the National Science Foundation.