Tim Searchinger

Princeton University | PU · Woodrow Wilson School of Public and International Affairs

High food insecurity in sub-Saharan Africa (SSA) and expected adverse effects of climate change have appropriately focused attention on climate adaptation, but there has been less focus on mitigating SSA’s agricultural emissions. Emissions from the region’s agricultural production processes and recent rates of agricultural expansion are 2–3 tCO 2 e...

After agriculture, wood harvest is the human activity that has most reduced the storage of carbon in vegetation and soils1,2. Although felled wood releases carbon to the atmosphere in various steps, the fact that growing trees absorb carbon has led to different carbon-accounting approaches for wood use, producing widely varying estimates of carbon...

In this report, WRI researchers explore how rising demand for food, wood and shelter is squeezing land that’s needed for storing carbon and protecting biodiversity. This research uses new modeling to give a true global picture of the carbon opportunity costs for land use and proposes a four-pronged approach–produce, protect, reduce, restore–for sus...

Transforming the global food system is necessary to avoid exceeding planetary boundaries. A robust evidence base is crucial to assess the scale and combination of interventions required for a sustainable transformation. We developed a risk assessment framework, underpinned by a meta-regression of 60 global food system modeling studies, to quantify...

Incoming policies will cause the European Union to harvest more wood, shift one-fifth of cropland to bioenergy and outsource deforestation, analysis shows. Incoming policies will cause the European Union to harvest more wood, shift one-fifth of cropland to bioenergy and outsource deforestation, analysis shows. Credit: Gustavo Basso/NurPhoto via Get...

Animal-based foods are nutritious and especially important to livelihoods and diets in developing countries, but they also inefficiently use resources. Beef production is becoming more efficient, but forests are still being cut down for new pasture. People say they want to eat more plants, but meat consumption is still rising. Despite seeming contr...

Previous estimates of tropical forest carbon loss in the twenty-first century using satellite data typically focus on its magnitude, whereas regional loss trajectories and associated drivers are rarely reported. Here we used different high-resolution satellite datasets to show a doubling of gross tropical forest carbon loss worldwide from 0.97 ± 0....

Significance Livestock supply chains account for 14.5% of global greenhouse gases (GHG) emissions. There is a consensus that approaches that improve cattle productivity while enhancing carbon sequestration can contribute to the multiple goals of improving ranchers’ livelihoods and mitigating climate change. Identifying policies that simultaneously...

For biodiversity protection to play a persuasive role in land‐use planning, conservationists must be able to offer objective systems for ranking which natural areas to protect or convert. Representing biodiversity in spatially explicit indices is challenging because it entails numerous judgments regarding what variables to measure, how to measure t...

Agriculture is expanding in tropical mountainous areas, yet its climatic effect is poorly understood. Here, we investigate how elevation regulates the biophysical climate impacts of deforestation over tropical mountainous areas by integrating satellite-observed forest cover changes into a high-resolution land–atmosphere coupled model. We show that...

Our previous blog, Regenerative Agriculture: Good for Soil Health, but Limited Potential to Mitigate Climate Change, generated a spirited discussion. Here we provide further elaboration on our conclusions. For information on ways to reduce agriculture’s GHG impact please see our blog on 6 Ways the US Can Curb Climate Change and Grow More Food. URL:...

Agriculture needs to close an 11-gigaton greenhouse gas (GHG) gap between expected emissions in 2050 and those needed to hold global warming below 2oC. Several noteworthy reports have proposed a range of mitigation options. Our World Resources Report: Creating a Sustainable Food Future, issued jointly with the World Bank and the UN, laid out 22 sol...

How can the world feed nearly 10 billion people by 2050 while also advancing economic development, protecting and restoring forests, and stabilizing the climate? It won’t be easy and will require major new efforts, but it can be done. Here are 10 important examples of technologies that can be part of the solution. https://www.wri.org/blog/2019/07...

Can we feed the world without destroying it? The ‘World Resources Report: Creating a Sustainable Food Future’ shows that it is possible – but there is no silver bullet. This final report focuses on technical opportunities and policies for cost-effective scenarios to meet food, land-use, and greenhouse gas emissions goals in 2050 in ways that can al...

In this Letter, the PANGAEA repository was referred to incorrectly in the ‘Code availability’ and ‘Data availability’ sections of Methods: the link should be 10.1594/PANGAEA.893761 instead of 10.1594/PANGAEA.877266. In addition, the sentence, “However, the more commonly used system 2 (75 kg ha−1 yr−1) generates roughly the same benefits as system 1...

By 2050, nearly 10 billion people will live on the planet. Can we produce enough food sustainably? The synthesis report of the World Resources Report: Creating a Sustainable Food Future shows that it is possible – but there is no silver bullet. This report offers a five-course menu of solutions to ensure we can feed everyone without increasing emis...

21 Killer charts succinctly present a five-course menu of solutions for sustainably feeding the population in 2050: (1) Reduce growth in demand for food and other agricultural products; (2) Increase food production without expanding agricultural land; (3) Protect and restore natural ecosystems; (4) Increase fish supply; and (5) Reduce GHG emissi...

This comment raises concerns regarding the way in which a new European directive, aimed at reaching higher renewable energy targets, treats wood harvested directly for bioenergy use as a carbon-free fuel. The result could consume quantities of wood equal to all Europe's wood harvests, greatly increase carbon in the air for decades, and set a danger...

Land-use changes are critical for climate policy because native vegetation and soils store abundant carbon and their losses from agricultural expansion, together with emissions from agricultural production, contribute about 20 to 25 per cent of greenhouse gas emissions1,2. Most climate strategies require maintaining or increasing land-based carbon³...

In the version of this Perspective originally published, in the last paragraph of the section ‘The US corn sector’, there was an incorrect mention of Fig. 3; it should have referred to Fig. 2. This has now been corrected. The Supplementary Information has also been updated to provide absolute numbers for avoided N pollution as calculated in the mai...

Nitrogen pollution has exceeded safe levels outlined in the the planetary boundaries literature. As agricultural production continues to intensify, pollution abatement will require acute increases in nitrogen-use efficiency. Policies that rely on the voluntary adoption of farm-level management practices have rarely led to significant reductions in...

The special issue Scaling up bioenergy? identifies major policy expectations attached to biofuels production worldwide, and it provides systematic reviews of actual biofuel performance and governance in these areas. Papers address the extent to which policy expectations related to climate change mitigation, energy security, rural livelihoods and ri...

While some studies find no room for the dedicated use of land for bioenergy because of growing food needs, other studies estimate large bioenergy potentials, even at levels greater than total existing human plant harvest. Analyzing this second category of studies, we find they have in various ways counted the carbon benefits of using land for biofu...

This chapter considers the food security challenge to 2030 and its implications for the sustainable development agenda. It first outlines three proposed food security targets that integrate sustainability and must be achieved by 2030: reduce the rate of food loss and waste by 50 per cent; reduce the greenhouse gas emissions from food production by...

A growing population with increasing consumption of milk and dairy require more agricultural output in the coming years, which potentially competes with forests and other natural habitats. This issue is particularly salient in the tropics, where deforestation has traditionally generated cattle pastures and other commodity crops such as corn and soy...

Biofuels have been promoted worldwide under the assumption that they can support several strategic policy goals, while mitigating associated risks. Drawing on published evidence on performance, contributing papers to this Special Section question assumptions commonly attributed to biofuels: their carbon neutrality, their positive effect on rural li...

Objective: This study was aimed at evaluating effects of cattle breed resources and alternative mixed-feeding practices on meat productivity and emission intensities from household farming systems in Daklak Province, Vietnam. Methods: Records from Local Yellow x Red Sindhi (Bos indicus; Lai Sind) and ½ Limousin, ½ Drought Master and ½ Red Angus...

The objective of this study was to determine enteric methane emission factors of beef catagories and develop scenarios to improve animal performance and reduce methane emission per kg live weight gain /unit product from extensive cattle production system. Methane emission was estimated according to tier 3 of IPCC (2006) using RUMINAT Model. Results...

Rapidly rising populations and likely increases in incomes in sub-Saharan Africa make tens of millions of hectares of cropland expansion nearly inevitable, even with large increases in crop yields. Much of that expansion is likely to occur in higher rainfall savannas, with substantial costs to biodiversity and carbon storage. Zambia presents an acu...

A protein scorecard to help consumers make more sustainable diet choices. It ranks foods from lowest (plant-based foods) to highest impact (beef, goat and lamb) based on GHG emissions from agricultural production and land use change

Installment 11 of Creating a Sustainable Food Future shows that for people who consume high amounts of meat and dairy, shifting to diets with a greater share of plant-based foods could significantly reduce agriculture’s pressure on the environment. It introduces a protein scorecard ranking foods from lowest (plant-based foods) to highest impact (be...

Installment 11 of Creating a Sustainable Food Future shows that for people who consume high amounts of meat and dairy, shifting to diets with a greater share of plant-based foods could significantly reduce agriculture’s pressure on the environment. It introduces a protein scorecard ranking foods from lowest (plant-based foods) to highest impact (be...

Improvements in nitrogen use efficiency in crop production are critical for addressing the triple challenges of food security, environmental degradation and climate change. Such improvements are conditional not only on technological innovation, but also on socio-economic factors that are at present poorly understood. Here we examine historical patt...

As global demand for livestock products (such as meat, milk, and eggs) is expected to double by 2050, necessary increases to future production must be reconciled with negative environmental impacts that livestock cause. This paper describes the LivestockPlus concept and demonstrates how the sowing of improved forages can lead to the sustainable int...

As global demand for livestock products (such as meat, milk and eggs) is expected to double by 2050, necessary increases to future production must be reconciled with negative environmental impacts that livestock cause. This paper describes the LivestockPlus concept and demonstrates how the sowing of improved forages can lead to the sustainable inte...

Debates about biofuels tend to focus separately on estimates of adverse effects on food security, poverty, and greenhouse gas (GHG) emissions driven by land-use change (LUC). These estimates often rely on global agriculture and land-use models. Be- cause models differ substantially in their estimates of each of these adverse effects, some argue tha...

Do the wet savannahs and shrublands of Africa provide a large reserve of potential croplands to produce food staples or bioenergy with low carbon and biodiversity costs? We find that only small percentages of these lands have meaningful potential to be low-carbon sources of maize (�2%) or soybeans (9.5–11.5%), meaning that their conversion would re...

A fall-planted winter cover crop is an agricultural management practice with multiple benefits that may include reducing nitrate (NO3) losses from artificial drained agricultural fields. While the practice is commonly used in the southern and eastern United States, little is known about its efficacy in midwestern states where winters are longer and...

Nitrate (NO3) losses from agricultural lands in the Midwest flow into the Mississippi River Basin (MRB) and contribute significantly to hypoxia in the Gulf of Mexico. Previous work has shown that cover crops can reduce loadings, but adoption rates are low, and the potential impact if cover crops were widely adopted is currently unknown. This paper...

The world’s agricultural system faces a great balancing act. To meet different human needs, by 2050 it must simultaneously produce far more food for a population expected to reach about 9.6 billion, provide economic opportunities for the hundreds of millions of rural poor who depend on agriculture for their livelihoods, and reduce environmental imp...

Estimates of global primary bioenergy potentials in the literature span almost three orders of magnitude. We narrow that range by discussing biophysical constraints on bioenergy potentials resulting from plant growth (NPP) and its current human use. In the last 30 years, terrestrial NPP was almost constant near 54 PgC yr􀀀1, despite massive efforts...

Global increases in population, consumption, and gross domestic product raise concerns about the sustainability of the current and future use of natural resources. The human appropriation of net primary production (HANPP) provides a useful measure of human intervention into the biosphere. The productive capacity of land is appropriated by harvestin...

How can the world adequately feed more than 9 billion people by 2050 in a manner that advances economic development and reduces pressure on the environment? This is one of the paramount questions the world faces over the next four decades. Answering it requires a “great balancing act” of three needs—each of which must be simultaneously met. First,...

Current Life Cycle Analysis (LCA) models indicate that crop‐based biofuels generate greenhouse gas savings, compared with fossil fuels. We argue that they do so only because they ignore the emissions of CO2 from vehicles burning the biofuels without determining if the biomass is “additional,” and because they underestimate the ultimate emissions of...

Many international policies encourage a switch from fossil fuels to bioenergy based on the premise that its use would not result in carbon accumulation in the atmosphere. Frequently cited bioenergy goals would at least double the present global human use of plant material, the production of which already requires the dedication of roughly 75% of ve...

Like the global financial crisis, which resulted in part from misguided accounting of mortgages, global policies to expand transportation biofuels and bioelectricity reflect an accounting error. Although the carbon accounting in these policies assumes that plant growth offsets all carbon released by burning biofuels, only “additional” plant growth...

Many international policies encourage a switch from fossil fuels to bioenergy based on the premise that its use would not result in carbon accumulation in the atmosphere. Frequently cited bioenergy goals would at least double the present global human use of plant material, the production of which already requires the dedication of roughly 75% of ve...

Curbing biofuels should halt price rises

Use of biofuels does not reduce emissions from energy combustion but may offset emissions by increasing plant growth or by reducing plant residue or other non-energy emissions. To do so, biofuel production must generate and use ‘additional carbon’, which means carbon that plants would not otherwise absorb or that would be emitted to the atmosphere...

The accounting now used for assessing compliance with carbon limits in the Kyoto Protocol and in climate legislation contains a far-reaching but fixable flaw that will severely undermine greenhouse gas reduction goals (1). It does not count CO2 emitted from tailpipes and smokestacks when bioenergy is being used, but it also does not count changes i...

Rules for applying the Kyoto Protocol and national cap and trade laws contain a major, but fixable, carbon accounting flaw in assessing bioenergy. The accounting now used for assessing compliance with carbon limits in the Kyoto Protocol and in climate legislation contains a far-reaching but fixable flaw that will severely undermine greenhouse gas r...

US ethanol production should exceed 12 billion gallons by 2010, and EISA 2007 mandates 36 billion gallons by 2022, diverting one-third of corn to ethanol and 13% of soybean production to biodiesel. Increased demand will ricochet through other agricultural sectors and alter production patterns and land use in the Corn Belt. This paper discusses effe...

Recent analyses of the energy and greenhouse-gas performance of alternative biofuels have ignited a controversy that may be best resolved by applying two simple principles. In a world seeking solutions to its energy, environmental, and food challenges, society cannot afford to miss out on the global greenhouse-gas emission reductions and the local...

The Report by T. Searchinger et al. (“Use of U.S. croplands for biofuels increases greenhouse gases through emissions from land-use change,” 29 February, p. 1238) provides one scenario for the conversion from a fossil-based energy economy to a bio-based, renewable-energy economy. However,

Most prior studies have found that substituting biofuels for gasoline will reduce greenhouse gases because biofuels sequester carbon through the growth of the feedstock. These analyses have failed to count the carbon emissions that occur as farmers worldwide respond to higher prices and convert forest and grassland to new cropland to replace the gr...

Combustion emissions per unit of energy: The Intergovernmental Panel on Climate Change provides default factors for greenhouse gas emissions per unit of energy from stationary installations using different forms of energy. Emissions rates from some biomass sources, such as wood and wood waste, are modestly higher than those for coal, oil or natural...

The environmental benefits derived from biofuels results from the plants used to engineer them. Plants take carbon dioxide out of the atmo- sphere. But it takes land to grow these plants, and using land for biofuels sacrifices other benefits of keeping land in its existing use. New analyses are now showing that the loss of greenhouse gases from dir...