Safeguarding the world's remaining forests is a high-priority goal. We assess the biophysical option space for feeding the world in 2050 in a hypothetical zero-deforestation world. We systematically ...combine realistic assumptions on future yields, agricultural areas, livestock feed and human diets. For each scenario, we determine whether the supply of crop products meets the demand and whether the grazing intensity stays within plausible limits. We find that many options exist to meet the global food supply in 2050 without deforestation, even at low crop-yield levels. Within the option space, individual scenarios differ greatly in terms of biomass harvest, cropland demand and grazing intensity, depending primarily on the quantitative and qualitative aspects of human diets. Grazing constraints strongly limit the option space. Without the option to encroach into natural or semi-natural land, trade volumes will rise in scenarios with globally converging diets, thereby decreasing the food self-sufficiency of many developing regions.
Summary
Environmentally extended multiregional input‐output (EE MRIO) tables have emerged as a key framework to provide a comprehensive description of the global economy and analyze its effects on ...the environment. Of the available EE MRIO databases, EXIOBASE stands out as a database compatible with the System of Environmental‐Economic Accounting (SEEA) with a high sectorial detail matched with multiple social and environmental satellite accounts. In this paper, we present the latest developments realized with EXIOBASE 3—a time series of EE MRIO tables ranging from 1995 to 2011 for 44 countries (28 EU member plus 16 major economies) and five rest of the world regions. EXIOBASE 3 builds upon the previous versions of EXIOBASE by using rectangular supply‐use tables (SUTs) in a 163 industry by 200 products classification as the main building blocks. In order to capture structural changes, economic developments, as reported by national statistical agencies, were imposed on the available, disaggregated SUTs from EXIOBASE 2. These initial estimates were further refined by incorporating detailed data on energy, agricultural production, resource extraction, and bilateral trade. EXIOBASE 3 inherits the high level of environmental stressor detail from its precursor, with further improvement in the level of detail for resource extraction. To account for the expansion of the European Union (EU), EXIOBASE 3 was developed with the full EU28 country set (including the new member state Croatia). EXIOBASE 3 provides a unique tool for analyzing the dynamics of environmental pressures of economic activities over time.
•Mixed-method approach combining statistics, archival research and interviews•Mathematically determined turning points expand on expert assessments•Mandatory regulations need to be supplemented by ...events in each stream•Unspecific subsidy programs produce patchwork policies or pull-forward effects•Tailor-made policy interventions require reflexive and adaptive policy integration
The need for rapid decarbonization of the energy system calls for an improved understanding how policy action may accelerate the market diffusion of low-carbon technologies. Turning points, in other words, i.e. points in time when market growth curves change direction, occur when politics, policy, and technology streams converge. Investigating photovoltaics, residential heat pump, and electric vehicle diffusion in Austria from 1970/1990 to 2018, we constellate when and why turning points occurred. Analyzing market statistics with the mathematical method of change point analysis allows identifying turning points and growth functions in diffusion curves. We used the Multiple Streams Approach to structure archival documents and findings from expert interviews to reconstruct critical events in past socio-political and socio-technological developments which triggered turning points. We find that observed diffusion processes change direction and pace at specific moments in time, rather than following a uniform s-shape. Mandatory regulations are key levers, but need to be supplemented by events in the respective streams: In the politics stream, overarching political strategies and model policies in other countries set the stage for low-carbon technologies. In the technology stream, R&D programs, product development, and quality labels support technological advancement. In the policy stream, however, ad-hoc subsidy programs tend to produce patchwork policies or only temporarily boost market diffusion. Continuously monitoring market processes may allow anticipation of upcoming turning points when the implementation of integrated policies can push combinations of complementary technologies.
Biodiversity and ecosystem service losses driven by land-use change are expected to intensify as a growing and more affluent global population requires more agricultural and forestry products, and ...teleconnections in the global economy lead to increasing remote environmental responsibility. By combining global biophysical and economic models, we show that, between the years 2000 and 2011, overall population and economic growth resulted in increasing total impacts on bird diversity and carbon sequestration globally, despite a reduction of land-use impacts per unit of gross domestic product (GDP). The exceptions were North America and Western Europe, where there was a reduction of forestry and agriculture impacts on nature accentuated by the 2007-2008 financial crisis. Biodiversity losses occurred predominantly in Central and Southern America, Africa and Asia with international trade an important and growing driver. In 2011, 33% of Central and Southern America and 26% of Africa's biodiversity impacts were driven by consumption in other world regions. Overall, cattle farming is the major driver of biodiversity loss, but oil seed production showed the largest increases in biodiversity impacts. Forestry activities exerted the highest impact on carbon sequestration, and also showed the largest increase in the 2000-2011 period. Our results suggest that to address the biodiversity crisis, governments should take an equitable approach recognizing remote responsibility, and promote a shift of economic development towards activities with low biodiversity impacts.
Agriculture is an important contributor to greenhouse gas (GHG) emissions. While the development of agricultural GHG emissions on national and global scales is well studied for the last three to six ...decades, little is known about their trajectory and drivers over longer periods. In this article, we address this research gap by calculating and analyzing GHG emissions related to agriculture in Austria from 1830 to 2018. We calculate territorial emissions on an annual basis and include all GHG emissions from the processes directly involved in agricultural production. Based on this time series, we quantify the relative importance of major drivers of changes in GHG emissions across time and agricultural product categories, applying a structural decomposition analysis. We find that agricultural GHG emissions in Austria increased by 69 % over the total study period, from 4.6 Mt. CO2e/yr in 1830 to 7.7 Mt. CO2e/yr in 2018. While emissions increased only moderately from 1830 to 1945 (+22 % overall), with strong fluctuations between 1914 and 1945, they doubled from 1945 to 1985. In the most recent period from 1985 to 2018, emissions fell by one third, with decreases leveling off over time. Our decomposition analysis reveals that increases in agricultural production per capita most importantly contributed to the high growth in GHG emissions from 1945 to 1985. Conversely, decreasing emission intensities of products and a more climate friendly product mix were key drivers in the emissions reduction observed after 1985. We also contribute to the discussion around the global warming potential star (GWP*), by calculating GHG emissions based on this alternative metric, and contextualize our data within total socio-economic GHG emission trends. By providing insights into the historical trends and drivers of agricultural GHG emissions, our findings enhance the understanding of their long-term historical dynamics and adds to the knowledge base for future mitigation efforts.
Global food systems contribute to climate change, the transgression of planetary boundaries and deforestation. An improved understanding of the environmental impacts of different food system futures ...is crucial for forging strategies to sustainably nourish a growing world population. We here quantify the greenhouse gas (GHG) emissions of global food system scenarios within a biophysically feasible “option space” in 2050 comprising all scenarios in which biomass supply – calculated as function of agricultural area and yields – is sufficient to cover biomass demand – derived from human diets and the feed demand of livestock. We assessed the biophysical feasibility of 520 scenarios in a hypothetical no-deforestation world.
For all feasible scenarios, we calculate (in) direct GHG emissions related to agriculture. We also include (possibly negative) GHG emissions from land-use change, including changes in soil organic carbon (SOC) and carbon sinks from vegetation regrowth on land spared from food production. We identify 313 of 520 scenarios as feasible. Agricultural GHG emissions (excluding land use change) of feasible scenarios range from 1.7 to 12.5 Gt CO2e yr−1. When including changes in SOC and vegetation regrowth on spare land, the range is between −10.7 and 12.5 Gt CO2e yr−1. Our results show that diets are the main determinant of GHG emissions, with highest GHG emissions found for scenarios including high meat demand, especially if focused on ruminant meat and milk, and lowest emissions for scenarios with vegan diets. Contrary to frequent claims, our results indicate that diets and the composition and quantity of livestock feed, not crop yields, are the strongest determinants of GHG emissions from food-systems when existing forests are to be protected.
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•We present an option space of 313 global food-system scenarios in 2050.•The scenarios were feasible without deforestation.•The net greenhouse gas emissions range from −10.7 to 12.5 Gt CO2e/yr.•Freed-up land that is left to regrowth shows huge carbon-sink potentials.•Crucial are diets and livestock feed-intake, but not crop-yield gains to cut GHGs.
Cascading use of biomass is a recognized strategy contributing to an efficient development of the bioeconomy and for mitigating climate change. This study aims at assessing the potential of cascading ...use of woody biomass for reducing GHG (greenhouse gas) emissions and increasing the overall wood flow efficiency in the European Union's forest and bioeconomy sectors. A scenario and life cycle approach was followed to quantify the potential benefits of cascading use of woody biomass. We started from a reference scenario in which (post-consumer) waste wood and paper are re-utilized for energy only (S0). Then we compared the reference scenario with two alternative scenarios, the current waste wood and paper recycling practices (S1) and the maximum technical potential to increase recycling of waste wood and paper flows (S2). Following a supply chain perspective, different stages of production were analysed, including forgone fossil-fuels substitution, optimization at manufacturing level and forest regrowth. Through cascading use, the wood use efficiency ratio (cascade factor) in the European wood sector would be increased by 23% (S0 vs S1) and 31% (S0 vs S2) and GHG emissions (cradle-to-gate energy use) would be reduced by 42% (28 MtCO2-eq/year) and 52% (35 MtCO2-eq/year) in scenarios S1 and S2. However, increased wood product cascading is counter effected in the short term by reduced savings in the energy sector by 49% and 48% (−43 and −42 MtCO2-eq/year) in scenarios S1 and S2 due to delayed availability of waste wood and waste paper fibers. This explorative study highlights the potential of cascading use of woody biomass in the wood production chains to contribute to a reduction of environmental impacts related to wood resource and energy use, but it also reveals trade-offs in terms of GHG emissions reduction, relevant especially in meeting short-term (2020–2030) renewable energy targets.
Short rotation plantations are often considered as holding vast potentials for future global bioenergy supply. In contrast to raising biomass harvests in forests, purpose‐grown biomass does not ...interfere with forest carbon (C) stocks. Provided that agricultural land can be diverted from food and feed production without impairing food security, energy plantations on current agricultural land appear as a beneficial option in terms of renewable, climate‐friendly energy supply. However, instead of supporting energy plantations, land could also be devoted to natural succession. It then acts as a long‐term C sink which also results in C benefits. We here compare the sink strength of natural succession on arable land with the C saving effects of bioenergy from plantations. Using geographically explicit data on global cropland distribution among climate and ecological zones, regionally specific C accumulation rates are calculated with IPCC default methods and values. C savings from bioenergy are given for a range of displacement factors (DFs), acknowledging the varying efficiency of bioenergy routes and technologies in fossil fuel displacement. A uniform spatial pattern is assumed for succession and bioenergy plantations, and the considered timeframes range from 20 to 100 years. For many parameter settings—in particular, longer timeframes and high DFs—bioenergy yields higher cumulative C savings than natural succession. Still, if woody biomass displaces liquid transport fuels or natural gas‐based electricity generation, natural succession is competitive or even superior for timeframes of 20–50 years. This finding has strong implications with climate and environmental policies: Freeing land for natural succession is a worthwhile low‐cost natural climate solution that has many co‐benefits for biodiversity and other ecosystem services. A considerable risk, however, is C stock losses (i.e., emissions) due to disturbances or land conversion at a later time.
How can spare cropland be used more efficiently in terms of climate change mitigation? By growing short rotation coppice for bioenergy or allowing cropland to revert to its natural state. We show that the more beneficial option depends on the timeframe considered, biophysical conditions in the considered region, upstream emissions of fuel supply, and the efficiency of the particular bioenergy route in displacing fossil fuels.
Global bioenergy potentials have been the subject of extensive research and continued controversy. Due to vast uncertainties regarding future yields, diets and other influencing parameters, estimates ...of future agricultural biomass potentials vary widely. Most scenarios compatible with ambitious climate targets foresee a large expansion of bioenergy, mainly from energy crops that needs to be kept consistent with projections of agriculture and food production. Using the global biomass balance model BioBaM, we here present an assessment of agricultural bioenergy potentials compatible with the Food and Agriculture Organization's (2018) 'Alternative pathways to 2050' projections. Mobilizing biomass at larger scales may be associated with systemic feedbacks causing greenhouse gas (GHG) emissions, e.g. crop residue removal resulting in loss of soil carbon stocks and increased emissions from fertilization. To assess these effects, we derive 'GHG cost supply-curves', i.e. integrated representations of biomass potentials and their systemic GHG costs. Livestock manure is most favourable in terms of GHG costs, as anaerobic digestion yields reductions of GHG emissions from manure management. Global potentials from intensive livestock systems are about 5 EJ/yr. Crop residues can provide up to 20 EJ/yr at moderate GHG costs. For energy crops, we find that the medium range of literature estimates (∼40 to 90 EJ/yr) is only compatible with FAO yield and human diet projections if energy plantations expand into grazing areas (∼4-5 million km2) and grazing land is intensified globally. Direct carbon stock changes associated with perennial energy crops are beneficial for climate mitigation, yet there are-sometimes considerable-'opportunity GHG costs' if one accounts the foregone opportunity of afforestation. Our results indicate that the large potentials of energy crops foreseen in many energy scenarios are not freely and unconditionally available. Disregarding systemic effects in agriculture can result in misjudgement of GHG saving potentials and flawed climate mitigation strategies.
•We map provisioning ESS and their relation to ecosystem functioning across the EU.•The HANPP framework allows to calculate ESS proxy indicators.•EU agricultural systems deliver high provisioning ESS ...per area.•Livestock generates higher HANPP than total cropland and grassland production.•Livestock systems exceed agroecosystem capacity in one third of all regions.•Grassland areas and perennial crops reduce ecosystem pressures.
Human intervention on land enhances the supply of provisioning ecosystem services, but also exerts pressures on ecosystem functioning. We utilize the Human Appropriation of Net Primary Production (HANPP) framework to assess these relations in European agriculture, for 220 NUTS2 regions. We put a particular focus on individual land system components, i.e. croplands, grasslands, and livestock husbandry and relate associated biomass flows to the potential net primary productivity NPP. For the reference year 2012, we find that 469 g dm/m2/yr (38% of NPPpot) of used biomass were harvested on total agricultural land, and that one tonne of annually harvested biomass is associated with 1.67 tonnes dry matter (dm) of HANPP, ranging from 0.8 to 8.1 tonnes dry matter (dm) across all regions. EU livestock systems are a large consumer of these provisioning ecosystem services, and invoking higher HANPP flows than current HANPP on cropland and grassland within the EU, even exceeding the potential NPP in one fifth of all NUTS2 regions. NPP remaining in ecosystems after provisioning society with biomass is essential for the functioning of ecosystems and is 563 g dm/m2/yr or 46% of NPPpot on all agricultural land. We conclude from our analysis that the HANPP framework provides useful indicators that should be integrated in future ecosystem service assessments.
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