Steven C. Amstrup

Polar bears in the southern Beaufort Sea II: Demography and population growth in relation to sea ice conditions

1

Internet Blogs, Polar Bears, and Climate-Change Denial by Proxy

Abstract Increasing surface temperatures, Arctic sea-ice loss, and other evidence of anthropogenic global warming (AGW) are acknowledged by every major scientific organization in the world. However, there is a wide gap between this broad scientific consensus and public opinion. Internet blogs have strongly contributed to this consensus gap by fomenting misunderstandings of AGW causes and consequences. Polar bears (Ursus maritimus) have become a “poster species” for AGW, making them a target of those denying AGW evidence. Here, focusing on Arctic sea ice and polar bears, we show that blogs that deny or downplay AGW disregard the overwhelming scientific evidence of Arctic sea-ice loss and polar bear vulnerability. By denying the impacts of AGW on polar bears, bloggers aim to cast doubt on other established ecological consequences of AGW, aggravating the consensus gap. To counter misinformation and reduce this gap, scientists should directly engage the public in the media and blogosphere.

Climate change threatens the world’s marine protected areas

Marine protected areas (MPAs) are a primary management tool for mitigating threats to marine biodiversity1,2. MPAs and the species they protect, however, are increasingly being impacted by climate change. Here we show that, despite local protections, the warming associated with continued business-as-usual emissions (RCP8.5)3 will likely result in further habitat and species losses throughout low-latitude and tropical MPAs4,5. With continued business-as-usual emissions, mean sea-surface temperatures within MPAs are projected to increase 0.035 °C per year and warm an additional 2.8 °C by 2100. Under these conditions, the time of emergence (the year when sea-surface temperature and oxygen concentration exceed natural variability) is mid-century in 42% of 309 no-take marine reserves. Moreover, projected warming rates and the existing ‘community thermal safety margin’ (the inherent buffer against warming based on the thermal sensitivity of constituent species) both vary among ecoregions and with latitude. The community thermal safety margin will be exceeded by 2050 in the tropics and by 2150 for many higher latitude MPAs. Importantly, the spatial distribution of emergence is stressor-specific. Hence, rearranging MPAs to minimize exposure to one stressor could well increase exposure to another. Continued business-as-usual emissions will likely disrupt many marine ecosystems, reducing the benefits of MPAs.Marine protected areas aim to conserve biodiversity and habitat. However continued high emissions causing changes in sea-surface temperatures and oxygen levels are likely to disrupt many ecosystems protected by MPAs.

The Impact of Climate Change on the Conservation and Survival of the Cheetah

Cheetah ( Acinonyx jubatus ) populations have dramatically declined due to habitat loss and fragmentation, declining prey base, conflict with livestock and farmed game, and illegal trade. Anthropogenic climate change multiplies all of these threats, increasing risks to future cheetah survival. Rising greenhouse gas (GHG) concentrations prolong atmospheric retention of the sun’s energy and assure global temperature increases. Increased frequencies of droughts and extreme rainfall, already observed, are “climate change symptoms” of warming that are expected to continue with unabated GHG rise. Anticipated declines in surface water availability will increase human food insecurity, human–wildlife competition, and landscape degradation, exacerbating the threats already facing cheetah conservation. Addressing these magnified threats will require societal actions that stop atmospheric GHG rise, and “scaling up” of local and regional conservation successes. Despite challenges, applying past lessons in large landscape conservation while addressing human needs, along with concerted global action, could assure the long-term persistence of wild cheetahs.

Corrigendum: Internet Blogs, Polar Bears, and Climate-Change Denial by Proxy

Jeffrey A. Harvey (j.jharvey@nioo.knaw.nl) is affiliated with the Department of Terrestrial Ecology at the Netherlands Institute of Ecology, in Wageningen. JAH, Daphne van den Berg, and Jacintha Ellers are with the Department of Ecological Sciences–Animal Ecology at the VU University Amsterdam, in The Netherlands. Remko Kampen works in Gouda, the Netherlands. Thomas, W. Crowther is with the Department of Terrestrial Ecology at the Netherlands Institute of Ecology, in Wageningen, and with the Institute of Integrative Biology, in Zürich, Switzerland. Peter Roessingh is with the Institute for Biodiversity and Ecosystem Dynamics at the University of Amsterdam, in The Netherlands. Bart Verheggen is affiliated with Amsterdam University College, in The Netherlands. Rascha J. M. Nuijten is with the Department of Animal Ecology at Netherlands Institute of Ecology, in Wageningen. Eric Post is affiliated with the Department of Wildlife, Fish, and Conservation Biology at the University of California, Davis. Stephan Lewandowsky is with the School of Experimental Psychology and Cabot Institute at the University of Bristol, in the United Kingdom, and with CSIRO Oceans and Atmosphere, in Hobart, Tasmania, Australia. Ian Stirling is affiliated with the Wildlife Research Division of Environment and Climate Change Canada, and with the Department of Biological Sciences at the University of Alberta, in Edmonton, Canada. Meena Balgopal is with the Department of Biology at Colorado State University, in Fort Collins. Steven C. Amstrup is affiliated with Polar Bears International, in Bozeman, Montana, and with the Department of Zoology and Physiology at the University of Wyoming, in Laramie. Michael E. Mann is affiliated with the Department of Meteorology and Atmospheric Science at Pennsylvania State University, in University Park.

Publisher Correction: Climate change threatens the world’s marine protected areas

In the version of this Letter originally published, the x axes titles of Fig. 3 erroneously read ‘Latitude’; they should have read ‘Longitude’. This has been corrected in the online versions of the Letter.

Anthropogenic Ocean Change: The Consummate Threat to Marine Mammal Welfare

Global warming is the consummate conservation and animal welfare challenge of our time. It defies traditional conservation management models and requires we broaden traditional cause and effect time horizons. Continually rising concentrations of CO2 and other greenhouse gases (GHGs) prolong retention of the sun’s energy before it escapes back into space—assuring that global temperatures must rise. Oceans have absorbed ~30% of anthropogenically emitted CO2 and over 90% of the heat trapped by the world’s enhanced greenhouse effect. Sea surface temperature and global ocean heat content have been rising accordingly. Along with rising temperatures, pH, oxygen saturation, salinity, and other aspects of ocean chemistry also are changing. Cumulative interactions among all of these symptoms of anthropogenic ocean change are and will continue to impact ocean biota. In this chapter, we summarize observed and projected anthropogenically driven ocean changes that have been and will continue to compromise marine mammal welfare.

One. Introduction to the Handbook

is published by Princeton University Press and copyrighted,