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Optional offsetting
24 07 2008 Will voluntary carbon markets genuinely tackle climate change or could they encourage further emissions?
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An end to hot air
24 07 2008
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Disease ecology: The silence of the robins
24 07 2008 A continent-wide analysis suggests that West Nile virus has severely affected bird populations associated with human habitats in North America. The declines parallel patterns of human disease caused by the virus.
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West Nile virus emergence and large-scale declines of North American bird populations
24 07 2008 Emerging infectious diseases present a formidable challenge to the conservation of native species in the twenty-first century. Diseases caused by introduced pathogens have had large impacts on species abundances, including the American chestnut, Hawaiian bird species and many amphibians. Changes in host population sizes can lead to marked shifts in community composition and ecosystem functioning. However, identifying the impacts of an introduced disease and distinguishing it from other forces that influence population dynamics (for example, climate) is challenging and requires abundance data that extend before and after the introduction. Here we use 26 yr of Breeding Bird Survey (BBS) data to determine the impact of West Nile virus (WNV) on 20 potential avian hosts across North America. We demonstrate significant changes in population trajectories for seven species from four families that concur with a priori predictions and the spatio-temporal intensity of pathogen transmission. The American crow population declined by up to 45% since WNV arrival, and only two of the seven species with documented impact recovered to pre-WNV levels by 2005. Our findings demonstrate the potential impacts of an invasive species on a diverse faunal assemblage across broad geographical scales, and underscore the complexity of subsequent community response.
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Biogeochemistry: Iron findings
24 07 2008 A huge phytoplankton bloom in the Southern Ocean yields estimates of how a continuous supply of iron affects oceanic carbon sequestration. But iron is not the only factor — nutrient supply is crucial too.
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Averting disaster: at what cost?
24 07 2008 Avoiding dangerous climate change will require considerable global efforts to reduce greenhouse gas emissions. A daunting challenge, but one that is practically and economically achievable, argues Jeffrey D. Sachs.
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Carbon storage deep down under
24 07 2008 As the world's largest trial carbon storage project gets underway, some are questioning its necessity. Hannah Hoag reports from Australia.
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Washington Watch
24 07 2008 This month, Kevin Vranes at the Center for Science and Technology Policy Research in Boulder, Colorado, reviews recent climate legislation passing through US Congress.
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Post-Kyoto pact: shaping the successor
24 07 2008 As discussions get underway over a global agreement to slash CO2 emissions beyond 2012, Amanda Leigh Haag looks at how the Kyoto Protocol has fared and the issues that will shape its successor.
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Healthiest corals hit hardest
24 07 2008
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Rainfall rules
24 07 2008
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Twilight zone transport
24 07 2008
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Fruiting fungi
24 07 2008
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Barking up the wrong tree?
24 07 2008
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