Nitrogen management is essential to prevent tropical oil palm plantations from causing ground-level ozone pollution

Abstract

More than half the world's rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (Elaeis guineensis): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an ''environmentally friendly'' fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O 3), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth's climate. Our measurements show that, at present, O 3 concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O 3 concentrations will reach 100 parts per billion (10 9 ) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided. air quality ͉ land use change ͉ sustainable development ͉ biofuel G round-level ozone (O 3 ) is a priority air pollutant that damages human health, plants, and materials, reduces crop productivity, and has direct and indirect effects on the Earth's climate system (1). It is formed in the atmosphere by reactions involving oxides of nitrogen (NO x ) and volatile organic compounds (VOCs) in the presence of sunlight. The terrestrial biosphere is a major source of both these families of trace gases; in fact, the great majority of reactive VOCs globally are of biogenic origin (2). Here we show, using integrated and fully comprehensive measurements of biosphere-to-atmosphere trace gas fluxes and atmospheric composition, together with atmospheric chemistry modeling, that conversion of tropical rainforest to oil palm plantations results in much greater emissions of these reactive trace gases that lead to O 3 formation. Increased NO x emissions will cause severe ground-level O 3 pollution (Ͼ 100 ppbv), but this pollution could be prevented by strict control of emissions of reactive nitrogen species to the atmosphere. Our study shows the importance of quantifying the current and future effects of land use change on air quality when assessing the ''environmental friendliness'' of palm oil and other biofuel crops. Of course, air quality is only a single consideration; in assessing the consequences of biofuel production, effects o...

Isoprene in poplar emissions: effects on new particle formation and OH concentrations

“…In all scenarios for future energy supply, fuels from biomass -so-called biofuels -and/or other energy sources from biomass, play an important role (Demirbas, 2008). Recent comprehensive analyses (Hewitt et al, 2009) demonstrated that conversion of tropical rainforest to oil palm plantations in Malaysia results in enhanced isoprene emission that lead to O 3 formation.…”

The impact of local surface changes in Borneo on atmospheric composition at wider spatial scales: coastal processes, land-use change and air quality

“…Even the VOC produced by natural rainforest can lead to harmful concentrations of ozone if NO x mixing ratios are allowed to enter the multi-ppbv range such as that found in rural Western Europe, North America and continental Asia [49,50]. VOC emissions from oil palm plantations, when combined with NO x concentrations typical of rural areas in the developed world, lead to potential peak ozone concentrations similar to those owing to heavy urbanization (not shown), indicating that significant air-quality issues may accompany large adoption of this crop in future unless tropical background NO x emissions are controlled [2]. However, not all crops have such potentially harmful effects on ozone formation.…”

“…Production for the global food industry has been one of the major drivers. Biofuels have been seen as environmentally friendly alternatives to fossil fuels but in recent years various questions have been raised about some potential negative impacts on greenhouse gas concentrations [16] and on air quality [2]. Analysis of all the stages relevant to these technologies are necessary and OP3 has provided some important new information on emissions and atmospheric chemistry.…”

“…Hewitt et al [2,3] provide a detailed description of the campaign objectives and various approaches and techniques adopted. Ground-based measurements at the Bukit Atur Global Atmosphere Watch station in the Danum Valley forest conservation area in Sabah, Malaysia (4858 0 N, 117850 0 E, 426 m above mean sea level) and at the Sabahmas oil palm plantation, also in Sabah (584 0 N, 118827 0 E), owned by Wilmar International Ltd., were complemented by airborne measurements made using the FAAM BAe146 research aircraft.…”

Regionalizing global climate models

“…Typical woody biofuel species are willow, eucalypt and oil palm, all of which have substantial rates of isoprene emissions that likely exceed emissions of local vegetation. Largescale conversion of tropical rainforest into oil palm plantations in areas of high (or projected to increase) NO x emissions of SE Asia therefore has the potential to be detrimental for local O 3 levels (Hewitt et al, 2009). At the same time will an increase in agricultural versus forest area also affect emissions of oxygenated BVOC (methanol, acetaldehyde; Chung et al, 2002;Goto et al, 2008).…”