Advanced Filters

Working Papers

Peng, Liqing et al. “The Carbon Costs of Global Wood Harvests.” Nature (2023): n. pag.

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 costs. Many approaches give the impression of low, zero or even negative greenhouse gas emissions from wood harvests because, in different ways, they offset carbon losses from new harvests with carbon sequestration from growth of broad forest areas3,4. Attributing this sequestration to new harvests is inappropriate because this other forest growth would occur regardless of new harvests and typically results from agricultural abandonment, recovery from previous harvests and climate change itself. Nevertheless some papers count gross emissions annually, which assigns no value to the capacity of newly harvested forests to regrow and approach the carbon stocks of unharvested forests. Here we present results of a new model that uses time discounting to estimate the present and future carbon costs of global wood harvests under different scenarios. We find that forest harvests between 2010 and 2050 will probably have annualized carbon costs of 3.5–4.2 Gt CO2e yr−1, which approach common estimates of annual emissions from land-use change due to agricultural expansion. Our study suggests an underappreciated option to address climate change by reducing these costs.

Searchinger, Timothy D. et al. “Revising Public Agricultural Support to Mitigate Climate Change.” Development Knowledge and Learning (2020): n. pag. Print.


The world faces a global land squeeze as the world population grows to 10 billion by 2050. Human demands for food, wood products, and urban uses will expand as the population grows and incomes rise. These demands will lead to more conversion of native habitats to agricultural and urban uses; in addition, more natural forests will be converted to wood plantations and increasing amounts of wood will be harvested from relatively natural forests. This growing demand for land-based products will compete with the ability of the remaining native habitats to store carbon and support biodiversity. 


Searchinger, Timothy et al. “EU Climate Plan Sacrifices Carbon Storage and Biodiversity for Bioenergy.” Nature 612 (2022): 27–30.


Searchinger, Timothy D. et al. A Pathway to Carbon Neutral Agriculture in Denmark. Washington, DC: World Resources Institute, 2021.
Subbarao, G. V., and Timothy D. Searchinger. “Opinion: A ‘more Ammonium solution’ to Mitigate Nitrogen Pollution and Boost Crop Yields.” Proceedings of the National Academy of Sciences 118.22 (2021): n. pag.
Zeng, Zhenzhong, and al. “Deforestation-Induced Warming over Tropical Mountain Regions Regulated by Elevation.” Nature Geoscience 14 (2021): 23–29.


Zeng, Zhenzhong et al. “ A Reversal in Global Terrestrial Stilling and Its Implications for Wind Energy Production .” Nature Climate Change 9 (2019): 979–985.
Searchinger, Tim et al. World Resources Report: Creating a Sustainable Food Future: A Menu of Solutions to Feed Nearly 10 Billion People by 2050. Washington, DC: World Resources Institute, 2019. Print.

The full, 566 page report, Creating a Sustainable Food Future:  A Menu of Solutions to Feed Nearly 10 Billion People by 2050 is now available. The report, of which I was lead author, explores how to meet food needs in 2050 while protecting ecosystems and reducing agricultural greenhouse gas emisisons to acceptable levels, and in ways that could help to reduce poverty and not exacerbate water challenges. The report was prepared by the World Resources Institute in collaboration with the World Bank, UN Environment, the UN Development Programme, and with technical contributions from INRA and CIRAD.

Some articles about the synthesis of the report appear in the New York Times, the Guardian, and Forbes.  


Zeng, Zhenzhong et al. “Highland Cropland Expansion and Forest Loss in Southeast Asia in the Twenty-First Century.” Nature Geoscience 11 (2018): 556–562.
Kanter, David R., and Timothy D. Searchinger. “A Technology-Forcing Approach to Reduce Nitrogen Pollution.” Nature Sustainability 1 (2018): 544–552.
Nitrogen losses from agriculture are already major sources of water and air pollution and greenhouse gas emissions and will grow as food production increases by 50% or more by 2050 even if farmers improve their management. This article suggests a technology-forcing, flexible regulatory strategy to encourage fertilizer manufactureers to increase the share and effectiveness of compounds that help limit nitrogen runoff. Such compounds, known as "enhanced efficiency fertilizers" have been shown on average to increase efficiency, reduce runoff and emissions, and increase yields but they have variable results and are not extensively used. This article suggests  incorporating an approached based on so-called "CAFE" standards, which have required automobile manuifacturers to increase the miles per gallon of the cars they sell over time. Requiring fertilizer manufacturers to sell more and better fertilizers over time could encourage the innovations necessary to truly alleviate nitrogen pollution.  Even without fertilizer innovations, the artgicle esetimates that applying this approach to the U.S. corn sector would save millions of dollars for farmers, generate billions in overall economic savings, and cause large reductions in nitrogen losses.  We suggest that governments such as those in China or California could enact these kinds of regulatory programs as part of their efforts to reduce greenhouse gas emissions and other forms of pollution.
Searchinger, Timothy D. et al. “Europe’s Renewable Energy Directive Poised to Harm Global Forests.” Nature Communications 9 (2018): n. pag. Print.

The European Commission has agreed to a renewable energy directive (RED), which will require that all countries in the European Union increase the percentage of energy that comes from renewable energy by 2030. Although this general regulation is admirable, it treats nearly all bioenergy as fully qualifying, low-carbon, renewable bioenergy including the harvest of wood from forests deliberately to burn.

In January 2018, roughly 800 scientists wrote to the European Parliament warning them that doing so would likely lead to forms of bioenergy that actually increased carbon in the atmosphere for decades compared even to using fossil fuels. This letter along with a video about the issue and other materials can be found at The letter encouraged the Parliament to limit this qualifying renewable energy from forest biomass to residues and wastes, but the Parliament rejected such an amendment. Eventually, negotiations with the European Commission and Council of States led to an agreed RED that also allows cutting down and burning of whole trees. 

This article provides an academic treatment of this issue and finds that the RED could plausibly lead Europe to burn an additional amount of wood equal to all its present wood harvest and increase greenhouse gas emissions from energy use by 10% compared to the alternative. It discusses why the so-called sustainability criteria do not prevent this result. 

Searchinger, Timothy D. et al. “Assessing the Efficiency of Changes in Land Use for Mitigating Climate Change.” Nature 564 (2018): 249–253. Print.
When land shifts from producing corn to soybeans to kumquats, or from cropland to grazing land or bioenergy, or back to forest, does that help or hurt the world’s potential to mitigate climate change? This paper finds that typical methods used by policymakers and researchers to answer this question have not properly focused on the need to increase the efficiency of land to meet growing demands for both food and carbon storage. This limitation is particularly important because climate strategies require storing more carbon in forests and other native vegetation even as the world must produce 50 percent or more additional food per year. The paper provides a new method, called the Carbon Benefits Index, for making this evaluation, and includes a new spreadsheet tool that people can use to evaluate the climate conseuqneces of different changes in land use or production methods for specific hectares or parcels of land.  The World Resources Institute will keep that tool and its updates and will be available here. For a more thorough explanation of the new paper and its significance, please read this explanation.


Ramírez-Restrepo, Carlos Alberto et al. “ Estimation of Methane Emissions from Local and Crossbreed Beef Cattle in Daklak Province of Vietnam .” Asian-Australas J Anim Sci 30.7 (2017): 1054–1060.
Fetzel, T. et al. “Quantification of Uncertainties in Global Grazing Systems Assessment.” Global Biogeochemical Cycles 31.7 (2017): 1089–1102.
Searchinger, Timothy D., Tim Beringer, and Asa Strong. “Does the World Have Low-Carbon Bioenergy Potential from the Dedicated Use of Land?.” Energy Policy 110 (2017): 434–446.


Estes, L. D. et al. “ Reconciling Agriculture, Carbon and Biodiversity in a Savannah Transformation Frontier .” Philosophical Transactions of the Royal Society B 371.1703 (2016): n. pag.
Ranganathan, Janet et al. Shifting Diets for a Sustainable Food Future. Vol. 11. World Resources Institute, 2016. Print.


Searchinger, T. et al. “Do Biofuel Policies Seek to Cut Emissions by Cutting Food?.” Science 347.6229 (2015): 1420–1422.

For many years, governments and researchers have debated whether corn and wheat ethanol reduce greenhouse gas emissions when counting the emissions from land use change needed to replace the food, and the debates have relied on different global agriculture and land use models. Ultimately, the U.S. Environmental Protection Agency and the California Air Resources Board found that these ethanols did generate modestly fewer emissions than gasoline, relying on different models. The European Commission also commissioned a model that found lower emissions. Meanwhile, many supporters of biofuels argue that because all these models differ in their results, impacts on both greenhouse gases and food are too uncertain to reflect in policies.  

In this paper, we analyzed the model results carefully and found that they estimate lower emissions for ethanol because they estimate that from 20-50% of the calories in food are not replaced. Physically, the emissions result from reduced respiration of carbon dioxide (and wastes) by people and livestock. The models attribute these "savings" to the biofuels.  And if these estimates were wrong, the models would estimate higher greenhouse gas emissions.  The paper therefore highlights that much of the debate between models is which adverse effects predominate not whether these ethanols generate adverse effects.

Those without subscriptions to the journal can gain free access to the paper through these links.



Full Text:


Searchinger, Tim et al. The Great Balancing Act. Washington, DC: World Resources Institute, 2013. Print.
Searchinger, Tim et al. Achieving Replacement Level Fertility. Washington, DC: World Resources Institute, 2013. Print.
Krausmann, Fridolin et al. “Global Human Appropriation of Net Primary Production Doubled in the 20th Century.” PNAS 110.25 (2013): 10324–10329.
Haberl, Helmut et al. “Bioenergy: How Much Can We Expect for 2050?.” Environmental Research Letters 8 (2013): n. pag.


Searchinger, Timothy D. et al. “Synergies in the Solutions to Africa’s Climate and Food Security Challenges.” Filling in the Gaps: Critical Linkages in Promoting Africa Food Security: An Atlantic Basin Perspective. Washington, DC: The German Marshall Fund of the United States, 2012. 67–106. Print.
Haberl, Helmut et al. “Correcting a Fundamental Error in Greenhouse Gas Accounting Related to Bioenergy.” Energy Policy 45 (2012): 18–23.
Smith, Keith A., and Timothy D. Searchinger. “Crop‐based Biofuels and Associated Environmental Concerns.” GCB Bioenergy 4.5 (2012): 479–484.
Searchinger, Tim. “Global Consequences of the Bioenergy Greenhouse Gas Accounting Error.” Energy, Transport & The Environment. London: Springer, 2012. 679–711.


Searchinger, Tim. “A Quick Fix to the Food Crisis.” Scientific American 2011: n. pag. Print.
Searchinger, Tim D. The Food Forest and Carbon Challenge. Washington, DC: National Wildlife Federation, 2011. Print.


Searchinger, Timothy D. et al. “ Bioenergy: Counting on Incentives—Response .” Science 327.5970 (2010): 1200–1201.
Searchinger, Timothy D. et al. “ Carbon Calculations to Consider—Response .” Science 327.5967 (2010): 781.
Searchinger, Timothy. “Biofuels and the Need for Additional Carbon.” Environmental Research Letters 5 (2010): n. pag.


Searchinger, Timothy, and Ralph Heimlich. “Likely Impacts of Biofuel Expansion on Midwest Land and Water Resources.” International Journal of Biotechnology 11 (2009): 127–149.
Bustamente, Mercedes M.C. et al. “ Chapter 16: What Are the Final Land Limits? .” Biofuels: Environmental Consequences and Interactions With Changing Land Use. Ithaca, NY: Cornell University Library’s Initiatives in Publishing (CIP), 2009. 271–291. Print.
Searchinger, Timothy D. “Chapter 2: Government Policies & Drivers of World Biofuels, Sustainability Criteria, Certification Proposals & Their Limitations.” Biofuels: Environmental Consequences and Interactions With Changing Land Use. Ithaca, NY: Cornell University Library’s Initiatives in Publishing (CIP), 2009. 37–52. Print.
Tilman, David et al. “ Beneficial Biofuels—The Food, Energy, and Environment Trilemma .” Science 325.5938 (2009): 270–271.
Tilman, David et al. “ Response—Biofuels .” Science Magazine 326.5958 (2009): 1346.
Searchinger, Timothy D. et al. “ Fixing a Critical Climate Accounting Error .” Science 326.5952 (2009): 527–528.


Searchinger, Timothy et al. “ Use of U.S. Croplands for Biofuels Increases Greenhouse Gases through Emissions from Land-Use Change .” Science 319.5867 (2008): 1238–1240.
Khosla, Vinod, Timothy D. Searchinger, and R. A. Houghton. “Biofuels: Clarifying Assumptions - Response.” Science 322.5900 (2008): 371–374.
Searchinger, Timothy D., and Ralph E. Heimlich. “Estimating Greenhouse Gas Emissions from Soy-Based US Biodiesel When Factoring in Emissions from Land Use Change.” The Lifecycle Carbon Footprint of Biofuels 2008: 35–45.
Kline, Keith L. et al. “ Biofuels: Effects on Land and Fire .” Science 321.5886 (2008): 199–201.