Jennifer Burney

Greenhouse gas mitigation by agricultural intensification

As efforts to mitigate climate change increase, there is a need to identify cost-effective ways to avoid emissions of greenhouse gases (GHGs). Agriculture is rightly recognized as a source of considerable emissions, with concomitant opportunities for mitigation. Although future agricultural productivity is critical, as it will shape emissions from conversion of native landscapes to food and biofuel crops, investment in agricultural research is rarely mentioned as a mitigation strategy. Here we estimate the net effect on GHG emissions of historical agricultural intensification between 1961 and 2005. We find that while emissions from factors such as fertilizer production and application have increased, the net effect of higher yields has avoided emissions of up to 161 gigatons of carbon (GtC) (590 GtCO2e) since 1961. We estimate that each dollar invested in agricultural yields has resulted in 68 fewer kgC (249 kgCO2e) emissions relative to 1961 technology (

Solar-powered drip irrigation enhances food security in the Sudano–Sahel

14.74/tC, or ∼

Real-time assessment of black carbon pollution in Indian households due to traditional and improved biomass cookstoves.

4/tCO2e), avoiding 3.6 GtC (13.1 GtCO2e) per year. Our analysis indicates that investment in yield improvements compares favorably with other commonly proposed mitigation strategies. Further yield improvements should therefore be prominent among efforts to reduce future GHG emissions.

Recent climate and air pollution impacts on Indian agriculture

Meeting the food needs of Africa’s growing population over the next half-century will require technologies that significantly improve rural livelihoods at minimal environmental cost. These technologies will likely be distinct from those of the Green Revolution, which had relatively little impact in sub-Saharan Africa; consequently, few such interventions have been rigorously evaluated. This paper analyzes solar-powered drip irrigation as a strategy for enhancing food security in the rural Sudano–Sahel region of West Africa. Using a matched-pair comparison of villages in northern Benin (two treatment villages, two comparison villages), and household survey and field-level data through the first year of harvest in those villages, we find that solar-powered drip irrigation significantly augments both household income and nutritional intake, particularly during the dry season, and is cost effective compared to alternative technologies.

The case for distributed irrigation as a development priority in sub-Saharan Africa.

Use of improved (biomass) cookstoves (ICs) has been widely proposed as a Black Carbon (BC) mitigation measure with significant climate and health benefits. ICs encompass a range of technologies, including natural draft (ND) stoves, which feature structural modifications to enhance air flow, and forced draft (FD) stoves, which additionally employ an external fan to force air into the combustion chamber. We present here, under Project Surya, the first real-time in situ Black Carbon (BC) concentration measurements from five commercial ICs and a traditional (mud) cookstove for comparison. These experiments reveal four significant findings about the tested stoves. First, FD stoves emerge as the superior IC technology, reducing plume zone BC concentration by a factor of 4 (compared to 1.5 for ND). Indoor cooking-time BC concentrations, which varied from 50 to 1000 μg m(-3) for the traditional mud cookstove, were reduced to 5-100 μg m(-3) by the top-performing FD stove. Second, BC reductions from IC models in the same technology category vary significantly: for example, some ND models occasionally emit more BC than a traditional cookstove. Within the ND class, only microgasification stoves were effective in reducing BC. Third, BC concentration varies significantly for repeated cooking cycles with same stove (standard deviation up to 50% of mean concentration) even in a standardized setup, highlighting inherent uncertainties in cookstove performance. Fourth, use of mixed fuel (reflective of local practices) increases plume zone BC concentration (compared to hardwood) by a factor of 2 to 3 across ICs.

Methods for attributing land-use emissions to products

Significance Rising temperatures because of increased emissions of long-lived greenhouse gases (LLGHGs) have had and will continue to have significant negative impacts on crop yields. However, other climate changes caused by short-lived climate pollutants (SLCPs) are also significant for agricultural productivity. The SLCPs black carbon and ozone impact temperature, precipitation, radiation, and—in the case of ozone—are directly toxic to plants. To our knowledge, this study provides the first integrated historical examination of the role of both SLCPs and LLGHGs on wheat and rice yields in India, and finds that the majority of losses are attributable to SLCPs. Agricultural cobenefits from SLCP mitigation are expected to be large, and because SLCPs have short atmospheric lifetimes, almost immediate. Recent research on the agricultural impacts of climate change has primarily focused on the roles of temperature and precipitation. These studies show that India has already been negatively affected by recent climate trends. However, anthropogenic climate changes are a result of both global emissions of long-lived greenhouse gases (LLGHGs) and other short-lived climate pollutants (SLCPs). Two potent SLCPs, tropospheric ozone and black carbon, have direct effects on crop yields beyond their indirect effects through climate; emissions of black carbon and ozone precursors have risen dramatically in India over the past three decades. Here, to our knowledge for the first time, we present results of the combined effects of climate change and the direct effects of SLCPs on wheat and rice yields in India from 1980 to 2010. Our statistical model suggests that, averaged over India, yields in 2010 were up to 36% lower for wheat than they otherwise would have been, absent climate and pollutant emissions trends, with some densely populated states experiencing 50% relative yield losses. [Our point estimates for rice (−20%) are similarly large, but not statistically significant.] Upper-bound estimates suggest that an overwhelming fraction (90%) of these losses is due to the direct effects of SLCPs. Gains from addressing regional air pollution could thus counter expected future yield losses resulting from direct climate change effects of LLGHGs.

Getting serious about the new realities of global climate change

Distributed irrigation systems are those in which the water access (via pump or human power), distribution (via furrow, watering can, sprinkler, drip lines, etc.), and use all occur at or near the same location. Distributed systems are typically privately owned and managed by individuals or groups, in contrast to centralized irrigation systems, which tend to be publicly operated and involve large water extractions and distribution over significant distances for use by scores of farmers. Here we draw on a growing body of evidence on smallholder farmers, distributed irrigation systems, and land and water resource availability across sub-Saharan Africa (SSA) to show how investments in distributed smallholder irrigation technologies might be used to (i) use the water sources of SSA more productively, (ii) improve nutritional outcomes and rural development throughout SSA, and (iii) narrow the income disparities that permit widespread hunger to persist despite aggregate economic advancement.

Solar-Powered Drip Irrigation Impacts on Crops Production Diversity and Dietary Diversity in Northern Benin

Roughly one-third of anthropogenic GHG emissions are caused by agricultural and forestry activities and landuse change (collectively, ‘land-use emissions’). Understanding the ultimate drivers of these emissions requires attributing emissions to specific land-use activities and products. Although quantities of land-use emissions are matters of fact, the methodological choices and assumptions required to attribute those emissions to activities and products depend on research goals and data availability. In this review, we explore several possible accounting methods. Our results highlight the sensitivity of accounting to temporal distributions of emissions and the consequences of replacing spatially-explicit data with aggregate proxies such as production or harvested area data. Different accounting options emphasize different causes of land-use emissions (e.g., proximate or indirect drivers of deforestation). To support public policies that effectively balance competing objectives, analysts should carefully consider and communicate implications of accounting choices.

Cookstoves illustrate the need for a comprehensive carbon market

For two decades, the central challenge facing climate-change policy makers involved efforts to control emissions of carbon dioxide. While diplomats looked at many different global-warming pollutants, they designed rules that mostly focused on carbon dioxide. Unfortunately, those efforts have largely failed, which has created yet another difficult challenge for the global community: how to manage the severe impacts of a warming world. New diplomatic strategies are needed. Diplomats must work harder on pollutants other than carbon dioxide—such as soot—that will be easier to regulate and can help build credibility in the international diplomatic regime. New science shows that soot and short-lived climate pollutants actually cause almost half of current global warming—much more than thought just a few years ago. Fortuitously, these pollutants are also relatively easy to manage, and success on this front will help catalyze the political support needed for the much more difficult, yet essential, task of making deep cuts in carbon dioxide. At the same time, the authors write, new thinking will be needed on how to help societies adapt, such as building networks of experts and local officials who are on the front lines of adaptation.

Prevalence of anaemia, deficiencies of iron and Vitamin A and their determinants in rural women and young children: A cross-sectional study in Kalalé district of northern Benin

Background: Meeting the food needs of Africas growing population will require innovative and appropriate technologies whose effectiveness needs to be assessed. Objective: To evaluate the impact of Solar Market Gardens (SMGs) on crops production diversity and dietary diversity in the Kalalé district of Northern Benin. Methods: In 2007, SMGs were installed in 2 villages for womens agricultural groups as a strategy for enhancing food and nutrition security. Data were collected through interviews at installation and 1 year later from all womens group households (30–35 women/group) and from a random representative sample of 30 households in each village, for both treatment and matched-pair comparison villages. Results: Comparison of baseline and endline data indicated increases in the variety of fruits and vegetables produced and consumed by SMG womens groups compared to other groups. The proportion of SMG women’s group households engaged in vegetable and fruit production significantly increased by 26% and 55%, respectively (P < .05). After controlling for baseline values, SMG womens groups were 3 times more likely to increase their fruit and vegetable consumption compared with comparison non-womens groups (P < .05). In addition, the percentage change in corn, sorghum, beans, oil, rice and fish purchased was significantly greater in the SMG women’s groups compared to other groups. At endline, 57% of the women used their additional income on food, 54% on health care, and 25% on education. Conclusions: Solar Market Gardens have the potential to improve household nutritional status through direct consumption and increased income to make economic decisions.