Reducing Global Warming: The Potential of Organic Agriculture

Climate change mitigation is urgent, and adaptation to climate change is crucial, particularly in agriculture, where food security is at stake. Agriculture, currently responsible for 20-30% of global greenhouse gas emissions (counting direct and indirect agricultural emissions), can however contribute to both climate change mitigation and adaptation. The main mitigation potential lies in the capacity of agricultural soils to sequester CO2 through building organic matter. This potential can be realized by employing sustainable agricultural practices, such as those commonly found within organic farming systems. Examples of these practices are the use of organic fertilizers and crop rotations including legume leys and cover crops. Mitigation is also achieved in organic agriculture through the avoidance of open biomass burning, and the avoidance of synthetic fertilizers, the production of which causes emissions from fossil fuel use. , Andreas Gattinger1, Nic Lampkin3, Urs Niggli1 Common organic practices also contribute to adaptation. Building soil organic matter increases water retention capacity, and creates more stabile, fertile soils, thus reducing vulnerability to drought, extreme precipitation events, floods and water logging. Adaptation is further supported by increased agro-ecosystem diversity of organic farms, based on management decisions, reduced nitrogen inputs and the absence of chemical pesticides. The high diversity together with the lower input costs of organic agriculture is key to reducing production risks associated with extreme weather events. All these advantageous practices are not exclusive to organic agriculture. However, they are core parts of the organic production system, in contrast to most non-organic agriculture, where they play a minor role only. Mitigation in agriculture is however not restricted to the agricultural sector alone. Consumer preferences for products from conventional or organic farms, seasonal and local production, pest and disease resistant varieties, etc. strongly influence agricultural production systems, and thus the overall mitigation potential of agriculture. Even more influential are meat consumption and food wastage. Any discussion on mitigation of climate change in agriculture thus needs to address the entire food chain, and to be linked to general sustainable development strategies. The main challenges to dealing appropriately with the climate change mitigation and adaptation potential of organic agriculture, and agriculture in general, stem from a) insufficient understanding of some of the basic processes, such as the interaction of N2O emissions and soil carbon sequestration, contributions of roots to soil carbon sequestration, and the life-cycle emissions of organic fertilizers, such as compost; b) lack of procedures for emissions accounting which adequately represent agricultural production systems with multiple and diverse outputs, which also encompass ecosystem services; c) the problem to identify and design adequate policy frameworks for supporting mitigation and adaptation in agriculture, i.e. such that do not put systemic approaches at a disadvantage due to difficulties in the quantification of emissions, and in their allocation to single products; d) the necessity to assure that the current focus on mitigation does not lead to neglect of other factors influencing the sustainability of agriculture, such as pesticide loads, eutrophication, acidification or soil erosion; and e) the open questions, how to address consumer behaviour and how to further changes in consumption patterns, in order to utilize their mitigation potential

Economic vitality in a transition to sustainability

The good news is that many of the solutions to this extraordinary problem are within reach. Many of the solutions to global warming are not only feasible, they are economically and socially beneficial. While some claim that addressing global warming will have a negative impact on the economy, the most recent report by the Intergovernmental Panel on Climate Change ("IPCC") asserts that there is substantial economic potential for the mitigation of greenhouse gas emissions over the coming decade. In fact, there is a growing global market to address global warming, and the United States must act now or risk being left behind.Climate change, mitigation, resilience

Reducing Global Warming: The Potential of Organic Agriculture

For a successful outcome at COP 15 in Copenhagen in December, viable policy paths for effective climate change mitigation need to be provided. In addition, adaptation is unavoidable. One key point is the integration of agriculture (accounting for 10-12% of global emissions, Smith et al. 2007) in a post-2012 agreement. Its main potential lies in its significant capacity to sequester CO2 in soils, and in its synergies between mitigation and adaptation. This potential is best utilized employing sustainable agricultural practices such as organic agriculture (OA). Conservative estimates of the total mitigation potential of OA amount to 4.5-6.5 Gt CO2eq/yr (of ca. 50 Gt CO2eq total global greenhouse gas emissions). Depending on agricultural management practices, much higher amounts seem however possible. Organic agriculture complements emission reduction efforts with its major sequestration potential, which is based on the intensive humus production (requiring CO2) of the fertile soils. In comparison to conventional agriculture, OA also directly contributes to emission reductions as it emits less N2O from nitrogen application (due to lower nitrogen input), less N2O and CH4 from biomass waste burning (as burning is avoided), and requires less energy, mainly due to zero chemical fertilizer use. Its synergies between mitigation and adaptation also exert a positive influence. This in part due to the increased soil quality, which reduces vulnerability to drought periods, extreme precipitation events and waterlogging. In addition, the high diversity of crops and farming activities in organic agriculture, together with its lower input costs, reduce economic risks. OA has additional benefits beyond its direct relevance for mitigation and adaptation to climate change and climate variability, as it helps to increase food security and water protection. In the following, key points of organic agriculture are briefly listed, together with references for detailed information. The data refer to the annual potential of a global shift of agriculture to organic practices

The Global Warming Potential of Building Materials: An Application of Life Cycle Analysis in Nepal

open6siThis paper analyzes the global-warming potential of materials used to construct the walls of 3 building types—traditional, semimodern, and modern—in Sagarmatha National Park and Buffer Zone in Nepal, using the life-cycle assessment approach. Traditional buildings use local materials, mainly wood and stone, while semimodern and modern buildings use different amounts of commercial materials, such as cement and glass wool. A comparison of the greenhouse gas emissions associated with the 3 building types, using as the functional unit 1 m2 of wall, found that traditional buildings release about one-fourth of the greenhouse gas emissions released by semimodern buildings and less than one-fifth of the emissions of modern buildings. However, the use of thermal insulation in the modern building walls helps to reduce the energy consumption for space heating and consequently to reduce the global warming potential. In 25 years, the total global warming potential of a traditional building will be 20% higher than that of a modern building. If local materials, such as wood, are used in building construction, the emissions from production and transportation could be dramatically reduced.openBhochhibhoya, Silu; Zanetti, Michela; Pierobon, Francesca; Gatto, Paola; Maskey, R. K.; Cavalli, RaffaeleBhochhibhoya, Silu; Zanetti, Michela; Pierobon, Francesca; Gatto, Paola; Maskey, R. K.; Cavalli, Raffael

Elevated CO2 and Warming Altered Grassland Microbial Communities in Soil Top-Layers.

As two central issues of global climate change, the continuous increase of both atmospheric CO2 concentrations and global temperature has profound effects on various terrestrial ecosystems. Microbial communities play pivotal roles in these ecosystems by responding to environmental changes through regulation of soil biogeochemical processes. However, little is known about the effect of elevated CO2 (eCO2) and global warming on soil microbial communities, especially in semiarid zones. We used a functional gene array (GeoChip 3.0) to measure the functional gene composition, structure, and metabolic potential of soil microbial communities under warming, eCO2, and eCO2 + warming conditions in a semiarid grassland. The results showed that the composition and structure of microbial communities was dramatically altered by multiple climate factors, including elevated CO2 and increased temperature. Key functional genes, those involved in carbon (C) degradation and fixation, methane metabolism, nitrogen (N) fixation, denitrification and N mineralization, were all stimulated under eCO2, while those genes involved in denitrification and ammonification were inhibited under warming alone. The interaction effects of eCO2 and warming on soil functional processes were similar to eCO2 alone, whereas some genes involved in recalcitrant C degradation showed no significant changes. In addition, canonical correspondence analysis and Mantel test results suggested that NO3-N and moisture significantly correlated with variations in microbial functional genes. Overall, this study revealed the possible feedback of soil microbial communities to multiple climate change factors by the suppression of N cycling under warming, and enhancement of C and N cycling processes under either eCO2 alone or in interaction with warming. These findings may enhance our understanding of semiarid grassland ecosystem responses to integrated factors of global climate change

Global warming will affect the maximum potential abundance of boreal plant species

Forecasting the impact of future global warming on biodiversity requires understanding how temperature limits the distribution of species. Here we rely on Liebig's Law of Minimum to estimate the effect of temperature on the maximum potential abundance that a species can attain at a certain location. We develop 95%‐quantile regressions to model the influence of effective temperature sum on the maximum potential abundance of 25 common understory plant species of Finland, along 868 nationwide plots sampled in 1985. Fifteen of these species showed a significant response to temperature sum that was consistent in temperature‐only models and in all‐predictors models, which also included cumulative precipitation, soil texture, soil fertility, tree species and stand maturity as predictors. For species with significant and consistent responses to temperature, we forecasted potential shifts in abundance for the period 2041–2070 under the IPCC A1B emission scenario using temperature‐only models. We predict major potential changes in abundance and average northward distribution shifts of 6–8 km yr−1. Our results emphasize inter‐specific differences in the impact of global warming on the understory layer of boreal forests. Species in all functional groups from dwarf shrubs, herbs and grasses to bryophytes and lichens showed significant responses to temperature, while temperature did not limit the abundance of 10 species. We discuss the interest of modelling the ‘maximum potential abundance’ to deal with the uncertainty in the predictions of realized abundances associated to the effect of environmental factors not accounted for and to dispersal limitations of species, among others. We believe this concept has a promising and unexplored potential to forecast the impact of specific drivers of global change under future scenarios.202

ENERGY EFFICIENCY AND LIFE CYCLE ANALYSIS OF ORGANIC AND CONVENTIONAL OLIVE GROVES IN THE MESSARA VALLEY, CRETE, GREECE.

Environmental Impacts of agricultural activities have to be assessed in order to address cultural practices and the type of farming that are best suited to avoid the trade-off between the Ecology and the Economy. Furthermore, this study, comparing the environmental impacts with the Life Cycle Analysis (LCA) of Organic and Conventional olive oil production, is proposing to consider the relationship between the Energy Efficiency and the environmental impacts, notably the Climate Change (Global Warming contribution through Greenhouse Gas emission). The LCA is used to take into account the impacts of the production system from the Cradle (input production) to the Farm gate (final farm product) and considers 7 environmental impacts potential categories: Global Warming, Acidification, Eutrophication, Biodiversity, Erosion, Resource depletion, Ground water depletion. The study also assesses the Energy efficiency of both systems. The results show a clear difference between organic and conventional production, namely a two-fold improvement of the energy efficiency in the organic production. Even if the differences are reduced when the results are calculated on the yield rather than the area, the organic methods have a far smaller contribution to Global warming, Eutrophication, Biodiversity loss, Soil loss, Groundwater depletion and Energy use whereas, the Acidification potential is comparable in both cases. The study recommends encouraging some of the cultural practices that are used in the organic farming methods in order to reduce the burden of agriculture on the local and global ecology as well as the natural resources

Reducing Global Warming and Adapting to Climate Change: The Potential of Organic Agriculture

Climate change mitigation is urgent and adaptation to climate change is crucial, particularly in agriculture, where food security is at stake. Agriculture, currently responsible for 20-30% of global greenhouse gas emissions counting direct and indirect agricultural emissions), can however contribute to both climate change mitigation and adaptation. The main mitigation potential lies in the capacity of agricultural soils to sequester CO2 through building organic matter. This potential can be realized by employing sustainable agricultural practices, such as those commonly found within organic farming systems. Examples of these practices are the use of organic fertilizers and crop rotations including legumes leys and cover crops. Mitigation is also achieved in organic agriculture through the avoidance of open biomass burning and the avoidance of synthetic fertilizers and the related production emissions from fossil fuels. Common organic practices also contribute to adaptation. Building soil organic matter increases water retention capacity, and creates more stabile, fertile soils, thus reducing vulnerability to drought, extreme precipitation events, floods and water logging. Adaptation is further supported by increased agro-ecosystem diversity of organic farms, due to reduced nitrogen inputs and the absence of chemical pesticides. The high diversity together with the lower input costs of organic agriculture is key in reducing production risks associated with extreme weather events. All these advantageous practices are not exclusive to organic agriculture. However, they are core parts of the organic production system, in contrast to most non-organic agriculture, where they play a minor role only. Mitigation in agriculture cannot be restricted to the agricultural sector alone, though. Consumer behaviour strongly influences agricultural production systems, and thus their mitigation potential. Significant factors are meat consumption and food wastage. Any discussion on mitigation climate change in agriculture needs to address the entire food chain and needs to be linked to general sustainable development strategies. The main challenges to climate change mitigation and adaptation in organic agriculture and agriculture in general concern a)the understanding of some of the basic processes, such as the interaction of N2O emissions and soil carbon sequestration, contributions of roots to soil carbon sequestration and the life-cycle emissions of organic fertilizers such as compost; b) approaches for emissions accounting that adequately represent agricultural production systems with multiple and diverse outputs and that also encompass ecosystem services; c) the identification and implementation of most adequate policy frameworks for supporting mitigation and adaptation in agriculture, i.e: not putting systemic approaches at a disadvantage due to difficulties in the quantification of emissions, and in their allocation to single products; d) how to assure that the current focus on mitigation does not lead to neglect of the other sustainability aspects of agriculture, such as pesticide loads, eutrophication, acidification or soil erosion and e) the question how to address consumer behaviour and how to utilize the mitigation potential of changes in consumption patterns

Life cycle analysis for the cultivation and combustion of miscanthus for biofuel compared with natural gas

As negative environmental and economic impacts of fossil fuels have escalated, so has the importance of renewable bioenergy crops whose feedstocks are noncompetitive with food supplies. Compared with fossil fuels, use of lignocellulosic feedstocks offers potential for greenhouse gas reduction and highly positive net energy returns because of low input demand and high yields per unit of land area, thus making them advantageous for the emerging biofuel industry. The aim of this study was to simulate environmental impacts of producing a biofuel grass for combustion use based on the inventory of inputs and their effects on eutrophication of surface waters; acidification of land and water; photochemical ozone-creation potential (i.e. smog); global atmospheric warming; and nonrenewable resource depletion (mainly fossil fuels). Hybrid miscanthus (Miscanthus x giganteus, or giant miscanthus), a perennial C4 grass originating from East Asia, was compared with natural gas by using a life-cycle analysis model for biomass production in France. The analysis showed a trade-off between natural gas and miscanthus. The latter had a lower global-warming potential and consumed less primary nonrenewable energy but produced more emissions that promote acidification and eutrophication than did natural gas

Surface reflectance and conversion efficiency dependence of technologies for mitigating global warming

A means of assessing the relative impact of different renewable energy technologies on global warming has been developed. All power plants emit thermal energy to the atmosphere. Fossil fuel power plants also emit CO2 which accumulates in the atmosphere and provides an indirect increase in global warming via the greenhouse effect. A fossil fuel power plant may operate for some time before the global warming due to its CO2 emission exceeds the warming due to its direct heat emission. When a renewable energy power plant is deployed instead of a fossil fuel power plant there may be a significant time delay before the direct global warming effect is less than the combined direct and indirect global warming effect from an equivalent output coal fired plant - the " business as usual" case. Simple expressions are derived to calculate global temperature change as a function of ground reflectance and conversion efficiency for various types of fossil fuelled and renewable energy power plants. These expressions are used to assess the global warming mitigation potential of some proposed Australian renewable energy projects. The application of the expressions is extended to evaluate the deployment in Australia of current and new geo-engineering and carbon sequestration solutions to mitigate global warming. Principal findings are that warming mitigation depends strongly on the solar to electric conversion efficiency of renewable technologies, geo-engineering projects may offer more economic mitigation than renewable energy projects and the mitigation potential of reforestation projects depends strongly on the location of the projects. © 2010 Elsevier Ltd