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Chapter 3 - Direct Solar Energy
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- By Dan Arvizu, Palani Balaya, Luisa F. Cabeza, K.G. Terry Hollands, Arnulf Jäger-Waldau, Michio Kondo, Charles Konseibo, Valentin Meleshko, Wesley Stein, Yutaka Tamaura, Honghua Xu, Roberto Zilles, Armin Aberle, Andreas Athienitis, Shannon Cowlin, Don Gwinner, Garvin Heath, Thomas Huld, Ted James, Lawrence Kazmerski, Margaret Mann, Koji Matsubara, Anton Meier, Arun Mujumdar, Takashi Oozeki, Oumar Sanogo, Matheos Santamouris, Michael Sterner, Paul Weyers, Eduardo Calvo, Jürgen Schmid
- Edited by Ottmar Edenhofer, Ramón Pichs-Madruga, Youba Sokona, Kristin Seyboth, Susanne Kadner, Timm Zwickel, Patrick Eickemeier, Gerrit Hansen, Steffen Schlömer, Christoph von Stechow, Patrick Matschoss
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- Book:
- Renewable Energy Sources and Climate Change Mitigation
- Published online:
- 05 December 2011
- Print publication:
- 21 November 2011, pp 333-400
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Summary
Executive Summary
Solar energy is abundant and offers significant potential for near-term (2020) and long-term (2050) climate change mitigation. There are a wide variety of solar technologies of varying maturities that can, in most regions of the world, contribute to a suite of energy services. Even though solar energy generation still only represents a small fraction of total energy consumption, markets for solar technologies are growing rapidly. Much of the desirability of solar technology is its inherently smaller environmental burden and the opportunity it offers for positive social impacts. The cost of solar technologies has been reduced significantly over the past 30 years and technical advances and supportive public policies continue to offer the potential for additional cost reductions. Potential deployment scenarios range widely—from a marginal role of direct solar energy in 2050 to one of the major sources of energy supply. The actual deployment achieved will depend on the degree of continued innovation, cost reductions and supportive public policies.
Solar energy is the most abundant of all energy resources. Indeed, the rate at which solar energy is intercepted by the Earth is about 10,000 times greater than the rate at which humankind consumes energy. Although not all countries are equally endowed with solar energy, a significant contribution to the energy mix from direct solar energy is possible for almost every country. Currently, there is no evidence indicating a substantial impact of climate change on regional solar resources.
8 - Cloud feedbacks
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- By David A. Randall, Department of Atmospheric Science, Colorado State University, Fort Collins, CO, Michael E. Schlesinger, Department of Atmospheric Sciences, University of Illinois, Urbana, IL, Valentin Meleshko, Main Geophysical Observatory, St Petersburg, Russia, Vener Galin, Department of Numerical Mathematics, Russian Academy of Sciences, Moscow, Russia, Jean-Jacques Morcette, European Centre for Medium Range Weather Forecasts, Reading, UK, Richard Wetherald, Geophysical Fluid Dynamics Laboratory, Princeton University, Princeton, NJ
- Edited by J. T. Kiehl, V. Ramanathan
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- Book:
- Frontiers of Climate Modeling
- Published online:
- 12 August 2009
- Print publication:
- 24 August 2006, pp 217-250
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Summary
Introduction
As discussed in Chapter 1, climate feedbacks are an integral aspect of the climate system. This chapter investigates the importance of cloud feedbacks. Although many of the best-known early climate models used prescribed clouds (e.g., Manabe and Bryan, 1969), the importance of potential changes in cloudiness for the problem of climate change has been recognized as a key factor since the 1970s (e.g., Arakawa, 1975; Charney et al., 1979). In particular, it is now widely appreciated that “cloud feedback” is a key source of uncertainty limiting the reliability of simulations of anthropogenic climate change (e.g., Houghton et al., 1990).
Nevertheless the whole concept of cloud feedback continues to be obscure, in part because the term “cloud feedback” is often used without being properly defined at all, and is rarely given a definition precise enough to show how it can be quantitatively measured. Further confusion arises from the fact that there are in fact many types of cloud feedbacks (e.g., Schneider, 1972; Schlesinger, 1985; 1988; 1989; Wielicki et al., 1995). In addition, it is widely perceived that existing atmospheric general circulation models (AGCMs) are incapable of making quantitatively realistic simulations of cloudiness.
The purposes of this chapter are to give a definition of cloud feedback, to discuss some particular types of cloud feedback, and to assess the prospects for simulations of cloud feedback on anthropogenic climate change.