Browsing by Author "Rockström, Johan"

Now showing 1 - 7 of 7

Drivers, 'Slow' Variables, 'Fast' Variables, Shocks, and Resilience
(2012) Walker, Brian H.; Carpenter, Stephen; Rockström, Johan; Crépin, Anne-Sophie; Peterson, Garry D.
"Different uses of the terms 'drivers,' 'variables,' and 'shocks' cause confusion in the literature and in discussions on the dynamics of ecosystems and social–ecological systems. Three main sources of confusion are unclear definition of the system, unclear definition of the role of people, and confusion between variables and drivers. As a contribution to resolving some of the confusion, we offer one interpretation of how the terms might be used."
Linkages Among Water Vapor Flows, Food Production, and Terrestrial Ecosystem Services
(1999) Rockström, Johan; Gordon, Line; Folke, Carl; Falkenmark, Malin; Engwall, Maria
"Global freshwater assessments have not addressed the linkages among water vapor flows, agricultural food production, and terrestrial ecosystem services. We perform the first bottom-up estimate of continental water vapor flows, subdivided into the major terrestrial biomes, and arrive at a total continental water vapor flow of 70,000 km3/yr (ranging from 56,000 to 84,000 km3/yr). Of this flow, 90% is attributed to forests, including woodlands (40,000 km3/yr), wetlands (1400 km3/yr), grasslands (15,100 km3/yr), and croplands (6800 km3/yr). These terrestrial biomes sustain society with essential welfare-supporting ecosystem services, including food production. By analyzing the freshwater requirements of an increasing demand for food in the year 2025, we discover a critical trade-off between flows of water vapor for food production and for other welfare-supporting ecosystem services. To reduce the risk of unintentional welfare losses, this trade-off must become embedded in intentional ecohydrological landscape management."
Planetary Boundaries: Exploring the Safe Operating Space for Humanity
(2009) Rockström, Johan; Steffen, Will; Noone, Kevin; Persson, Åsa; Chapin, F. Stuart; Lambin, Eric; Lenton, Timothy M.; Scheffer, Marten; Folke, Carl; Schellnhuber, Hans Joachim; Nykvist, Björn; de Wit, Cynthia A.; Hughes, Terry; van der Leeuw, Sander; Rodhe, Henning; Sörlin, Sverker; Snyder, Peter K.; Costanza, Robert; Svedin, Uno; Falkenmark, Malin; Karlberg, Louise; Corell, Robert W.; Fabry, Victoria J.; Hansen, James; Walker, Brian H.; Liverman, Diana; Richardson, Katherine; Crutzen, Paul; Foley, Jonathan
"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 ³ 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."
Rain: The Neglected Resource: Embracing Green Water Management Solutions
(2005) Falkenmark, Malin; Rockström, Johan
"The water necessary to produce the food required for an expanding human population is usually discussed only as an issue of blue water for irrigation (the water we use from rivers and aquifers). This discussion neglects that most food production is from rain fed farming. This is critical not least in hunger and poverty stricken areas with rapid population growth, areas that depend not on blue water but on green water from infi ltrated rain (the soil moistures used by plants and returned as vapour flow). A shift in water thinking which considers soil moisture is essential in order to fi nd realistic and sustainable options to feed the world of tomorrow. Rain: The Neglected Resource elucidates how a shift in thinking can change how we view the world’s water resources."
Resilience Thinking: Integrating Resilience, Adaptability and Transformability
(2010) Folke, Carl; Carpenter, Stephen; Walker, Brian H.; Scheffer, Marten; Chapin, Terry; Rockström, Johan
"Resilience thinking addresses the dynamics and development of complex social–ecological systems (SES). Three aspects are central: resilience, adaptability and transformability. These aspects interrelate across multiple scales. Resilience in this context is the capacity of a SES to continually change and adapt yet remain within critical thresholds. Adaptability is part of resilience. It represents the capacity to adjust responses to changing external drivers and internal processes and thereby allow for development along the current trajectory (stability domain). Transformability is the capacity to cross thresholds into new development trajectories. Transformational change at smaller scales enables resilience at larger scales. The capacity to transform at smaller scales draws on resilience from multiple scales, making use of crises as windows of opportunity for novelty and innovation, and recombining sources of experience and knowledge to navigate social–ecological transitions. Society must seriously consider ways to foster resilience of smaller more manageable SESs that contribute to Earth System resilience and to explore options for deliberate transformation of SESs that threaten Earth System resilience."
Water and Development in the Developing Countries: A Study Commissioned by the European Parliament
(2000) Björklund, Gunilla; Brismar, Anna; Ehlin, Ulf; Falkenmark, Malin; Lundqvist, Jan; Rockström, Johan; Swain, Ashok
"The aim of the study is to assist the European Parliament in formulating long term strategies and short term policies to aid developing countries to prepare and implement policies leading to efficient, equitable and ecologically sound water resources management. A policy and strategy must be possible to translate into feasible programmes and projects that can be executed."
Water Harvesting for Upgrading of Rainfed Agriculture
(2001) Falkenmark, Malin; Fox, Patrick; Persson, Gunn; Rockström, Johan
"The report is mainly divided into three parts. The first part presents the hydroclimatic constraints and challenges facing farmers, and gives a brief presentation of water harvesting and farmers coping strategies to manage water scarcity. In the second part of the report regional approaches from sub-Saharan Africa, India and China are presented. Based on the financial support available and the possibility to obtain information from literature, it was decided to base the India chapter on literature and the China chapter on a short study visit to Gansu and Hebei provinces. Most knowledge in the field of water harvesting, among the authors of the report, is from sub-Saharan Africa. Therefore the sub-Saharan Africa chapter gives a comprehensive description of water harvesting experiences with emphasis on floodwater harvesting and storage systems supplementary irrigation. The last part of the report reflects knowledge gaps that need to be filled, both regarding technical -, process - and systems research."