Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems

Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

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Climate Change 2007: The Physical Science Basis.

The talk with present the key results of the IPCC Working Group III 5th assessment report. Concluding four years of intense scientific collaboration by hundreds of authors from around the world, the report responds to the request of the world's governments for a comprehensive, objective and policy neutral assessment of the current scientific knowledge on mitigating climate change. The report has been extensively reviewed by experts and governments to ensure quality and comprehensiveness.

Climate change 2014 - Mitigation of climate change

Since the 1900s, the link between soil biotic activity, soil organic matter (SOM) decomposition and stabilization, and soil aggregate dynamics has been recognized and intensively been studied. By 1950, many studies had, mostly qualitatively, investigated the influence of the five major factors (i.e. soil fauna, microorganisms, roots, inorganics and physical processes) on this link. After 1950, four theoretical mile-stones related to this subject were realized. The first one was when Emerson [Nature 183 (1959) 538] proposed a model of a soil crumb consisting of domains of oriented clay and quartz particles. Next, Edwards and Bremner [J. Soil Sci. 18 (1967) 64] formulated a theory in which the solid-phase reaction between clay minerals, polyvalent cations and SOM is the main process leading to microaggregate formation. Based on this concept, Tisdall and Oades [J. Soil Sci. 62 (1982) 141] coined the aggregate hierarchy concept describing a spatial scale dependence of mechanisms involved in micro- and macroaggregate formation. Oades [Plant Soil 76 (1984) 319] suggested a small, but very important, modification to the aggregate hierarchy concept by theorizing the formation of microaggregates within macroaggregates. Recent research on aggregate formation and SOM stabilization extensively corroborate this modification and use it as the base for furthering the understanding of SOM dynamics. The major outcomes of adopting this modification are: (1) microaggregates, rather than macroaggregates protect SOM in the long term; and (2) macroaggregate turnover is a crucial process influencing the stabilization of SOM. Reviewing the progress made over the last 50 years in this area of research reveals that still very few studies are quantitative and/or consider interactive effects between the five factors. The quantification of these relationships is clearly needed to improve our ability to predict changes in soil ecosystems due to management and global change. This quantification can greatly benefit from viewing aggregates as dynamic rather than static entities and relating aggregate measurements with 2D and 3D quantitative spatial information.

A history of research on the link between (micro)aggregates, soil biota, and soil organic matter dynamics

The effects of land use change on soil carbon stocks are of concern in the context of international policy agendas on greenhouse gas emissions mitigation. This paper reviews the literature for the influence of land use changes on soil C stocks and reports the results of a meta analysis of these data from 74 publications. The meta analysis indicates that soil C stocks decline after land use changes from pasture to plantation (−10%), native forest to plantation (−13%), native forest to crop (−42%), and pasture to crop (−59%). Soil C stocks increase after land use changes from native forest to pasture (+ 8%), crop to pasture (+ 19%), crop to plantation (+ 18%), and crop to secondary forest (+ 53%). Wherever one of the land use changes decreased soil C, the reverse process usually increased soil carbon and vice versa. As the quantity of available data is not large and the methodologies used are diverse, the conclusions drawn must be regarded as working hypotheses from which to design future targeted investigations that broaden the database. Within some land use changes there were, however, sufficient examples to explore the role of other factors contributing to the above conclusions. One outcome of the meta analysis, especially worthy of further investigation in the context of carbon sink strategies for greenhouse gas mitigation, is that broadleaf tree plantations placed onto prior native forest or pastures did not affect soil C stocks whereas pine plantations reduced soil C stocks by 12–15%.

Soil carbon stocks and land use change: a meta analysis

The News of the Week article that reports on Senator Kay Bailey Hutchison (R-TX) questioning the need to fund social science research at the National Science Foundation is alarming and shortsighted (“Senate panel chair asks why NSF funds social sciences,” 12 May, p. [829][1]). Social science research is at the fundamental core of basic research and has much to contribute to the economic viability of the United States. Twenty years of direct and jointly funded social and ecosystem science research at Colorado State University's Natural Resource Ecology Laboratory has produced deep insights into environmental and societal impacts of political upheaval, land use, and climate change in parts of Africa, Asia, and the Americas. Beyond greatly advancing our understanding of the coupled human-environmental system, the partnership of social and ecosystem science has brought scientists and decision-makers together to begin to develop solutions to difficult problems.

Insights from the social sciences about the vulnerability, sustainability, and resilience of social and environmental systems have greatly increased our understanding of the complex interactions of the world on which we depend. The contributions of social and ecological science for data analyses associated with spatial relationships, transfer of goods and services, valuation, and decision-making processes have improved our understanding of how human activities are altering environmental systems worldwide. These findings have become the core of policy and development decisions used throughout the world.

It is critical that the NSF support social science funding and that, as budget decisions are made, the social science allocation should move forward equally with increases as in other basic and applied research. Failure to do so will further hinder U.S. competitiveness in the future and will slow transfer of knowledge and usefulness to the public.

 [1]: /lookup/doi/10.1126/science.312.5775.829a

http://science.sciencemag.org/content/sci/312/5779/1470.2.full.pdf

Don't sell social science short.

When asking the question, ‘‘How can institutions design science policies for the benefit of decision makers?’’ Sarewitz and Pielke [Sarewitz, D., Pielke Jr., R.A., this issue. The neglected heart of science policy: reconciling supply of and demand for science. Environ. Sci. Policy 10] posit the idea of ‘‘reconciling supply and demand of science’’ as a conceptual tool for assessment of science programs. We apply the concept to the U.S. Department of Agriculture’s (USDA) carbon cycle science program. By evaluating the information needs of decision makers, or the ‘‘demand’’, along with the supply of information by the USDA, we can ascertain where matches between supply and demand exist, and where science policies might miss opportunities. We report the results of contextual mapping and of interviews with scientists at the USDA to evaluate the production and use of current agricultural global change research, which has the stated goal of providing ‘‘optimal benefit’’ to decision makers on all levels. We conclude that the USDA possesses formal and informal mechanisms by which scientists evaluate the needs of users, ranging from individual producers to Congress and the President. National-level demands for carbon cycle science evolve as national and international policies are explored. Current carbon cycle science is largely derived from those discussions and thus anticipates the information needs of producers. However, without firm agricultural carbon policies, such information is currently unimportant to producers.

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Reconciling the supply of and demand for carbon cycle science in the U.S. agricultural sector

Quantification and decision support tools for US agricultural soil carbon sequestration

G-Range introduction ................................................................ 1 Baseline simulation methods ......................................................... 2 Table 1. The global surfaces used in comparison ........................ 3 Baseline simulation results ........................................................... 5 Table 2. Baseline results for selected responses ......................... 6 Table 3. Baseline results for facet cover .................. .......... 9 Sensitivity analysis methods ......................................................... 11 Sensitivity analysis results ........................................................... . 13 Future steps ............................................................................. 110 Acknowledgements .................................................................... 110 Literature Cited ......................................................................... 110 Appendix A. Parameters within the landscape unit f ile .......................... 113 Appendix B. The FIT.AML Arc macro language program ...................... 118

Adjustment and Sensitivity Analyses of a Beta Global Rangeland Model

Rangelands are uncultivated lands that include grasslands, savannahs, steppes, shrub lands, deserts and tundra. The native vegetation on rangelands is predominantly grasses, forbs and shrubs (Kothmann, 1974). Rangelands cover 31 percent of the land surface area of the United States (Havstad et al., 2009), and up to half of the land surface area worldwide (Lund, 2007). Most land areas that are not developed, not cultivated, not forested and not solid rock or ice can be classified as rangelands. Because of their extent, a small change in soil carbon (C) stocks across rangeland ecosystems would have a large impact on greenhouse gas (GHG) accounts. There are 761 million acres of rangelands in the United States (Havstad et al., 2009), half of which are public lands in the West (Follett, Kimble and Lal, 2001). The primary activity focus on rangelands is grazing. Rangelands and grazing lands are two broadly overlapping categories. United States grazing lands, including managed pasturelands, have the potential to remove an additional 198 million tonnes of carbon dioxide (CO 2 ) from the atmosphere per year for 30 years (Follett, Kimble and Lal, 2001), when saturation is reached. This would offset 3.3 percent of United States CO 2 emissions from fossil fuels (EIA, 2009, and help protect rangeland soil quality for the future. The past 20 years have seen a tremendous enhancement in the understanding of soil C, both its role in the global C cycle and the factors that influence its dynamics. Although soil organic carbon (SOC) has long been of interest to scientists, technical advisers and land managers as an indicator of soil health, the link between the C cycle and global climate change has provided increased impetus for quantification and, ultimately, management. Even if atmospheric concentrations of GHGs were quickly stabilized, anthropogenic warming and sea levels would continue to rise for centuries

Richard T. Conant

Papers

Don't sell social science short.

Reconciling the supply of and demand for carbon cycle science in the U.S. agricultural sector

Quantification and decision support tools for US agricultural soil carbon sequestration

Adjustment and Sensitivity Analyses of a Beta Global Rangeland Model

Soil carbon sequestration in United States rangelands