Science
8 January 2016 vol 351, issue 6269, pages 101-200
http://www.sciencemag.org/current.dtl

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Editorial
Biggest opportunity of our age
Sir David King
Sir David King is the United Kingdom Foreign Secretary’s Special Representative for Climate Change.
The importance of the agreement reached at the Paris climate Conference of Parties (COP21) last month cannot be overstated. It is a major step toward preventing some of the worst risks that climate change presents to the global economy and security. Now is the time to seize the opportunity that this moment represents. We must transform world economies away from fossil fuels toward a more sustainable low-carbon future.

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Policy Forum
Development and Environment
Balancing hydropower and biodiversity in the Amazon, Congo, and Mekong
K. O. Winemiller, P. B. McIntyre, L. Castello, E. Fluet-Chouinard, T. Giarrizzo, S. Nam, I. G. Baird, W. Darwall, N. K. Lujan, I. Harrison, M. L. J. Stiassny, R. A. M. Silvano, D. B. Fitzgerald, F. M. Pelicice, A. A. Agostinho, L. C. Gomes, J. S. Albert, E. Baran, M. Petrere Jr., C. Zarfl, M. Mulligan, J. P. Sullivan, C. C. Arantes, L. M. Sousa, A. A. Koning, D. J. Hoeinghaus, M. Sabaj, J. G. Lundberg, J. Armbruster, M. L. Thieme, P. Petry, J. Zuanon, G. Torrente Vilara, J. Snoeks,
C. Ou, W. Rainboth, C. S. Pavanelli, A. Akama, A. van Soesbergen, and L. Sáenz
Science 8 January 2016: 128-129.
The world’s most biodiverse river basins—the Amazon, Congo, and Mekong—are experiencing an unprecedented boom in construction of hydropower dams. These projects address important energy needs, but advocates often overestimate economic benefits and underestimate far-reaching effects on biodiversity and critically important fisheries. Powerful new analytical tools and high-resolution environmental data can clarify trade-offs between engineering and environmental goals and can enable governments and funding institutions to compare alternative sites for dam building. Current site-specific assessment protocols largely ignore cumulative impacts on hydrology and ecosystem services as ever more dams are constructed within a watershed (1). To achieve true sustainability, assessments of new projects must go beyond local impacts by accounting for synergies with existing dams, as well as land cover changes and likely climatic shifts (2, 3). We call for more sophisticated and holistic hydropower planning, including validation of technologies intended to mitigate environmental impacts. Should anything less be required when tampering with the world’s great river ecosystems?

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The Anthropocene is functionally and stratigraphically distinct from the Holocene
Review
Colin N. Waters, et al