Identifying and quantifying planetary boundaries that must not be transgressed could help prevent human activities from causing unacceptable environmental change, argue Johan Rockstrom and colleagues.

/pdf/a-safe-operating-space-for-humanity-tynyc6i2kf.pdf

A safe operating space for humanity

:The carbon sink capacity of the world’s agricultural and degraded soils is 50 to 66% of the historic carbon loss of 42 to 78 gigatons of carbon. The rate of soil organic carbon sequestration with adoption of recommended technologies depends on soil texture and structure, rainfall, temperature, farming system, and soil management. Strategies to increase the soil carbon pool include soil restoration and woodland regeneration, no-till farming, cover crops, nutrient management, manuring and sludge application, improved grazing, water conservation and harvesting, efficient irrigation, agroforestry practices, and growing energy crops on spare lands. An increase of 1 ton of soil carbon pool of degraded cropland soils may increase crop yield by 20 to 40 kilograms per hectare (kg/ha) for wheat, 10 to 20 kg/ha for maize, and 0.5 to 1 kg/ha for cowpeas. As well as enhancing food security, carbon sequestration has the potential to offset fossilfuel emissions by 0.4 to 1.2 gigatons of carbon per year, or 5 to 15% of the global fossil-fuel emissions.

/pdf/soil-carbon-sequestration-impacts-on-global-climate-change-1w7459lbbk.pdf

Soil carbon sequestration impacts on global climate change and food security.

The resilience perspective is increasingly used as an approach for understanding the dynamics of social–ecological systems. This article presents the origin of the resilience perspective and provides an overview of its development to date. With roots in one branch of ecology and the discovery of multiple basins of attraction in ecosystems in the 1960–1970s, it inspired social and environmental scientists to challenge the dominant stable equilibrium view. The resilience approach emphasizes non-linear dynamics, thresholds, uncertainty and surprise, how periods of gradual change interplay with periods of rapid change and how such dynamics interact across temporal and spatial scales. The history was dominated by empirical observations of ecosystem dynamics interpreted in mathematical models, developing into the adaptive management approach for responding to ecosystem change. Serious attempts to integrate the social dimension is currently taking place in resilience work reflected in the large numbers of sciences involved in explorative studies and new discoveries of linked social–ecological systems. Recent advances include understanding of social processes like, social learning and social memory, mental models and knowledge–system integration, visioning and scenario building, leadership, agents and actor groups, social networks, institutional and organizational inertia and change, adaptive capacity, transformability and systems of adaptive governance that allow for management of essential ecosystem services.

Resilience: the emergence of a perspective for social-ecological systems analyses

Anthropogenic pressures on the Earth System have reached a scale where abrupt global environmental change can no longer be excluded. We propose a new approach to global sustainability in which we define planetary boundaries within which we expect that humanity can operate safely. Transgressing one or more planetary boundaries may be deleterious or even catastrophic due to the risk of crossing thresholds that will trigger non-linear, abrupt environmental change within continental- to planetary-scale systems. We have identified nine planetary boundaries and, drawing upon current scientific understanding, we propose quantifications for seven of them. These seven are climate change (CO2 concentration in the atmosphere <350 ppm and/or a maximum change of +1 W m-2 in radiative forcing); ocean acidification (mean surface seawater saturation state with respect to aragonite ≥ 80% of pre-industrial levels); stratospheric ozone (<5% reduction in O3 concentration from pre-industrial level of 290 Dobson Units); biogeochemical nitrogen (N) cycle (limit industrial and agricultural fixation of N2 to 35 Tg N yr-1) and phosphorus (P) cycle (annual P inflow to oceans not to exceed 10 times the natural background weathering of P); global freshwater use (<4000 km3 yr-1 of consumptive use of runoff resources); land system change (<15% of the ice-free land surface under cropland); and the rate at which biological diversity is lost (annual rate of <10 extinctions per million species). The two additional planetary boundaries for which we have not yet been able to determine a boundary level are chemical pollution and atmospheric aerosol loading. We estimate that humanity has already transgressed three planetary boundaries: for climate change, rate of biodiversity loss, and changes to the global nitrogen cycle. Planetary boundaries are interdependent, because transgressing one may both shift the position of other boundaries or cause them to be transgressed. The social impacts of transgressing boundaries will be a function of the social-ecological resilience of the affected societies. Our proposed boundaries are rough, first estimates only, surrounded by large uncertainties and knowledge gaps. Filling these gaps will require major advancements in Earth System and resilience science. The proposed concept of "planetary boundaries" lays the groundwork for shifting our approach to governance and management, away from the essentially sectoral analyses of limits to growth aimed at minimizing negative externalities, toward the estimation of the safe space for human development. Planetary boundaries define, as it were, the boundaries of the "planetary playing field" for humanity if we want to be sure of avoiding major human-induced environmental change on a global scale.

/pdf/planetary-boundaries-exploring-the-safe-operating-space-for-ir5ysgjg96.pdf

Planetary boundaries: Exploring the safe operating space for humanity

▪ Abstract We explore the social dimension that enables adaptive ecosystem-based management. The review concentrates on experiences of adaptive governance of social-ecological systems during periods of abrupt change (crisis) and investigates social sources of renewal and reorganization. Such governance connects individuals, organizations, agencies, and institutions at multiple organizational levels. Key persons provide leadership, trust, vision, meaning, and they help transform management organizations toward a learning environment. Adaptive governance systems often self-organize as social networks with teams and actor groups that draw on various knowledge systems and experiences for the development of a common understanding and policies. The emergence of “bridging organizations” seem to lower the costs of collaboration and conflict resolution, and enabling legislation and governmental policies can support self-organization while framing creativity for adaptive comanagement efforts. A resilient social-eco...

/pdf/adaptive-governance-of-social-ecological-systems-4doqvfxaqg.pdf

Adaptive governance of social-ecological systems

Schlesinger and Jiang [1991a, b, c] and Risbey, Handel, and Stone [1991a, b] have exchanged views on the advisability of delaying responses to the greenhouse issue. The debate has primarily concerned interpreting the uncertainty of results obtained from model experiments, particularly with regard to predictions on regional and local scales, given that climate models are still very crude. By and large, I agree with the criticism of Risbey et al., but I am surprised about the lack of discussion of another aspect of the issue, which is the most important. It concerns more generally the problem of how to utilize scientific information in the development of a response policy. Only in passing did Risbey et al. [1991] mention: “In addition, investments in infrastructure over the next decade will influence the energy mix and greenhouse gas emissions over the next several decades.” The experience gained in the slow progress of the ongoing negotiations about a climate convention show us that the key issue in the present context is a socioeconomic one. The following short comments may be of interest.

[Comment on “The Greenhouse Debate: Time for action?”] The use of scenarios in the Greenhouse Debate

Effect on the biosphere of elevated atmospheric CO2 [8] (multiple letters)

http://link.springer.com/content/pdf/10.1007/978-90-481-9476-6_10.pdf

Askö 1994: Economic Growth, Carrying Capacity, and the Environment

The report “Net primary production of a forest ecosystem with experimental CO2 by enrichment” by E.H. DeLucia et al. (14 May, p. [1177][1]) provides excellent and much-needed experimental work on the responses of the terrestrial biosphere to elevated atmospheric carbon dioxide (CO2). However, we are concerned about the report's last statement (also appearing in the abstract), which extrapolates measurements of net primary production (NPP) from this one experiment to the world's forests as a whole, suggesting that they could absorb as much as 50% of the projected fossil fuel emissions of CO2 in 2050. This projection gives a misleading, perhaps erroneous, picture of the role of the terrestrial biosphere in the global carbon cycle.

First, NPP is not the appropriate measurement to apply when considering the net uptake (or release) of CO2 by the terrestrial biosphere on a biome or larger spatial scale and over several decades. The most appropriate concept is net biome production (NBP) ([1][2]), which includes not only NPP, but also losses of carbon resulting from heterotrophic respiration, fires, insect-induced mortality, logging, and other natural and human-induced disturbances ([2][3]).

In contrast to global terrestrial NPP, which is about 60 picograms of carbon per year, global terrestrial NBP is about ± 1 or 2 picograms per year.

Second, there is considerable difficulty in extrapolating up in time and space from a single experiment based on a step-change in CO2 concentration over a young, rapidly growing stand of trees, as noted by the authors of the report immediately before the final statement.

Third, applying the same methodology for extrapolation as used in this report, we conclude that the world's forests should now be taking up at least 3 picograms of carbon per year of fossil-fuel emissions. This is significantly higher than current estimates of terrestrial carbon sequestration [for example, ([3][4])] and is inconsistent with atmospheric inverse calculations, as well as with estimates of oceanic carbon uptake.

In the current, post-Kyoto international political climate, scientific statements about the behavior of the terrestrial carbon cycle must be made with care, especially extrapolations from stand-level experiments or observations.

1. [↵][5]1. J.N. Galloway, 2. J.M. Melillo
 1. E.D. Schulze, 2. M. Heimann
 , in Asian Change in the Context of Global Change, J.N. Galloway, J.M. Melillo, Eds. (Cambridge Univ. Press, Cambridge, 1998), pp. 145-161 (No. 3, IGBP Book Series,.
 

2. [↵][6]1. IGBP Terrestrial Carbon Working Group
 , Science 280, 1393 (1998).
 [OpenUrl][7][Abstract/FREE Full Text][8]

3. [↵][9]1. D.S. Schimel
 , Global Change Biol. 1, 77 (1995).
 [OpenUrl][10]

# Effect on the Biosphere of Elevated Atmospheric CO2 {#article-title-2}

NPP is the difference between total, annually integrated photosynthesis (gross primary production) and plant respiration and therefore represents the rate of carbon uptake from the atmosphere by ecosystems ([1][2]). By assuming that all forests of the world are similar to our young, fast-growing stand of loblolly pine, we attempted to constrain an estimate of the maximum net increment of NPP when the atmosphere contains 560 parts per million of CO2. Our value for forest uptake, 50% of the anticipated CO2 emissions from fossil fuels in the year 2050, indicates that forests will not solve the global warming problem for us. And, as Bolin et al. indicate, actual long-term carbon storage will be much less than NPP, owing to the activity of soil microbes, fires, human land-use changes, and so forth, which act to return CO2 to the atmosphere.

1. 1. W.H. Schlesinger
 , Biogeochemistry (Academic Press, San Diego, CA, 1997).

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Effect on the Biosphere of Elevated Atmospheric CO2

Dear Sir, In a recent paper describing results of forecasting by numerical methods (STAFF MEMBERS, UNIVERSITY OF STOCKHOLM, 1954), it was stated that the correlation between observed and computed changes is not a satisfactory measure of the goodness of a forecast. Previously the same group (Staff Members, University of Stockholm, 1952) had raised the objection that a correlation coefficient measures the similarity in behaviour of two variables without any reference to systematic errors such as a difference in scale of the variations. DOI: 10.1111/j.2153-3490.1955.tb01163.x

Bert Bolin

Papers

[Comment on “The Greenhouse Debate: Time for action?”] The use of scenarios in the Greenhouse Debate

Effect on the biosphere of elevated atmospheric CO2 [8] (multiple letters)

Askö 1994: Economic Growth, Carrying Capacity, and the Environment

Effect on the Biosphere of Elevated Atmospheric CO2

On «Results of forecasting with the barotropic model»