Mitigating Greenhouse Gas and Ammonia Emissions from Swine Manure Management: A System Analysis.

Gaseous emissions from animal manure are considerable contributor to global ammonia (NH3) and agriculture greenhouse gas (GHG) emissions. Given the demand to promote mitigation of GHGs while fostering sustainable development of the Paris Agreement, an improvement of management systems is urgently needed to help mitigate climate change and to improve atmospheric air quality. This study presents a meta-analysis and an integrated assessment of gaseous emissions and mitigation potentials for NH3, methane (CH4), and nitrous oxide (N2O) (direct and indirect) losses from four typical swine manure management systems (MMSs). The resultant emission factors and mitigation efficiencies allow GHG and NH3 emissions to be estimated, as well as mitigation potentials for different stages of swine operation. In particular, changing swine manure management from liquid systems to solid-liquid separation systems, coupled with mitigation measures, could simultaneously reduce GHG emissions by 65% and NH3 emissions by 78%. The resultant potential reduction in GHG emissions from China's pig production alone is greater than the entire GHG emissions from agricultural sector of France, Australia, or Germany, while the reduction in NH3 emissions is equivalent to 40% of the total NH3 emissions from the European Union. Thus, improved swine manure management could have a significant impact on global environment issues.

Reducing emissions from agriculture to meet the 2 °C target.

More than 100 countries pledged to reduce agricultural greenhouse gas (GHG) emissions in the 2015 Paris Agreement of the United Nations Framework Convention on Climate Change. Yet technical information about how much mitigation is needed in the sector vs. how much is feasible remains poor. We identify a preliminary global target for reducing emissions from agriculture of ~1 GtCO2 e yr-1 by 2030 to limit warming in 2100 to 2 °C above pre-industrial levels. Yet plausible agricultural development pathways with mitigation cobenefits deliver only 21-40% of needed mitigation. The target indicates that more transformative technical and policy options will be needed, such as methane inhibitors and finance for new practices. A more comprehensive target for the 2 °C limit should be developed to include soil carbon and agriculture-related mitigation options. Excluding agricultural emissions from mitigation targets and plans will increase the cost of mitigation in other sectors or reduce the feasibility of meeting the 2 °C limit.

Environmental impacts of beef production: Review of challenges and perspectives for durability.

Beef makes a substantial contribution to food security, providing protein, energy and also essential micro-nutrients to human populations. Rumination allows cattle - and other ruminant species - to digest fibrous feeds that cannot be directly consumed by humans and thus to make a net positive contribution to food balances. This contribution is of particular importance in marginal areas, where agro-ecological conditions and weak infrastructures do not offer much alternative. It is also valuable where cattle convert crop residues and by-products into edible products and where they contribute to soil fertility through their impact on nutrients and organic matter cycles. At the same time, environmental sustainability issues are acute. They chiefly relate to the low efficiency of beef cattle in converting natural resources into edible products. Water use, land use, biomass appropriation and greenhouse gas emissions are for example typically higher per unit of edible product in beef systems than in any other livestock systems, even when corrected for nutritional quality. This particularly causes environmental pressure when production systems are specialized towards the delivery of edible products, in large volumes. The paper discusses environmental challenges at global level, recognizing the large diversity of systems. Beef production is faced with a range of additional sustainability challenges, such as changing consumer perceptions, resilience to climate change, animal health and inequities in access to land and water resources. Entry-points for environmental sustainability improvement are discussed within this broader development context.