The mission of the Alaska Center for Climate Assessment and Policy is to assess the socioeconomic and biophysical impacts of climate variability in Alaska, make this information available to local and regional decision-makers, and improve the ability of Alaskans to adapt to a changing climate. The site has links to archived webinars.
The Atlantic meridional overturning circulation (AMOC) is a system of ocean currents that has an essential role in Earth's climate, redistributing heat and influencing the carbon cycle1, 2. The AMOC has been shown to be weakening in recent years 1 ; this decline may reflect decadal-scale variability in convection in the Labrador Sea, but short observational datasets preclude a longer-term perspective on the modern state and variability of Labrador Sea convection and the AMOC1, 3-5. Here we provide several lines of palaeo-oceanographic evidence that Labrador Sea deep convection and the AMOC have been anomalously weak over the past 150 years or so (since the end of the Little Ice Age, LIA, approximately AD 1850) compared with the preceding 1,500 years. Our palaeoclimate reconstructions indicate that the transition occurred either as a predominantly abrupt shift towards the end of the LIA, or as a more gradual, continued decline over the past 150 years; this ambiguity probably arises from non-AMOC influences on the various proxies or from the different sensitivities of these proxies to individual components of the AMOC. We suggest that enhanced freshwater fluxes from the Arctic and Nordic seas towards the end of the LIA-sourced from melting glaciers and thickened sea ice that developed earlier in the LIA-weakened Labrador Sea convection and the AMOC. The lack of a subsequent recovery may have resulted from hysteresis or from twentieth-century melting of the Greenland Ice Sheet 6 . Our results suggest that recent decadal variability in Labrador Sea convection and the AMOC has occurred during an atypical, weak background state. Future work should aim to constrain the roles of internal climate variability and early anthropogenic forcing in the AMOC weakening described here.
The Center for Climate Change Law (CCCL) at Columbia Law School develops legal techniques to fight climate change, trains law students and lawyers in their use, and develops databases on climate law and regulation.
Conducts research and provide reports, information and expert advice about issues related to global climate change and international climate policy with the aim of acquiring knowledge that can help mitigate the climate problem and enhance international climate cooperation.
Despite the growth in knowledge about the effects of a warming Arctic on its cold-adapted species, the mechanisms by which these changes affect animal populations remain poorly understood. Increasing temperatures, declining sea ice and altered wind and precipitation patterns all may affect the fitness and abundance of species through multiple direct and indirect pathways. Here we demonstrate previously unknown effects of rain-on-snow (ROS) events, winter precipitation, and ice tidal surges on the Arctic's largest land mammal. Using novel field data across seven years and three Alaskan and Russian sites, we show arrested skeletal growth in juvenile muskoxen resulting from unusually dry winter conditions and gestational ROS events, with the inhibitory effects on growth from ROS events lasting up to three years post-partum. Further, we describe the simultaneous entombment of 52 muskoxen in ice during a Chukchi Sea winter tsunami (ivuniq in Iñupiat), and link rapid freezing to entrapment of Arctic whales and otters. Our results illustrate how once unusual, but increasingly frequent Arctic weather events affect some cold-adapted mammals, and suggest that an understanding of species responses to a changing Arctic can be enhanced by coalescing groundwork, rare events, and insights from local people.
CIG is an internationally recognized interdisciplinary research group studying the impacts of natural climate variability and global climate change on local communities in the western U.S. region, with most work focused on the Pacific Northwest.
The Intergovernmental Panel on Climate Change was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) to provide the world with a clear scientific view on the current state of climate change and its potential environmental and socioeconomic consequences.
Carbon and nitrogen isotopes analyses were performed on marine mammal bone collagen from three archaeological sites (ad 1170-1813) on Cape Espenberg (Kotzebue Sound, northwestern Alaska) as well as modern animals harvested from the same area to examine long-term trends in foraging ecology and sea ice productivity. We observed significant and dramatic changes in ringed seal stable isotope values between the early 19th and early 21st centuries, likely due to changing sea ice productivity and reduced delivery of organic matter to the benthos driven by recent warming in the Arctic. These data highlight the importance of the archaeological record for providing a long-term perspective on environmental variation and interpreting recent changes driven by anthropogenic processes.
Rabies is a serious zoonotic disease with significant public health consequences in the circumpolar North. Recent studies have advanced our understanding of the disease ecology in Alaska. In this paper, we review historical records of rabies in Alaska ranging from the late nineteenth century to the present, analyse the public health impact in the state and review studies on disease ecology before assessing challenges and anticipated altered disease dynamics in the face of a rapidly changing North. Rabies is a disease that has been present in Alaska continuously for over 100 years. It is maintained in bats and foxes with the arctic fox likely playing a bigger role in maintaining the virus, although a multi-host system with both red and arctic foxes cannot be excluded. Some modelling evidence suggest a possible decrease in rabies due to a changing climate, although uncertainty is high around these predictions for rabies distribution in Alaska into the future.