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Author Hausfather, Z.; Cowtan, K.; Clarke, D.C.; Jacobs, P.; Richardson, M.; Rohde, R. url  openurl
  Title Assessing recent warming using instrumentally homogeneous sea surface temperature records Type Journal Article
  Year (down) 2017 Publication Science Advances Abbreviated Journal Sci Adv  
  Volume 3 Issue 1 Pages e1601207  
  Keywords Climate change; homogeneity; sea surface temperature  
  Abstract Sea surface temperature (SST) records are subject to potential biases due to changing instrumentation and measurement practices. Significant differences exist between commonly used composite SST reconstructions from the National Oceanic and Atmospheric Administration's Extended Reconstruction Sea Surface Temperature (ERSST), the Hadley Centre SST data set (HadSST3), and the Japanese Meteorological Agency's Centennial Observation-Based Estimates of SSTs (COBE-SST) from 2003 to the present. The update from ERSST version 3b to version 4 resulted in an increase in the operational SST trend estimate during the last 19 years from 0.07 degrees to 0.12 degrees C per decade, indicating a higher rate of warming in recent years. We show that ERSST version 4 trends generally agree with largely independent, near-global, and instrumentally homogeneous SST measurements from floating buoys, Argo floats, and radiometer-based satellite measurements that have been developed and deployed during the past two decades. We find a large cooling bias in ERSST version 3b and smaller but significant cooling biases in HadSST3 and COBE-SST from 2003 to the present, with respect to most series examined. These results suggest that reported rates of SST warming in recent years have been underestimated in these three data sets.  
  Call Number Serial 1667  
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Author Lee, A.H.; Eme, J.; Mueller, C.A.; Manzon, R.G.; Somers, C.M.; Boreham, D.R.; Wilson, J.Y. file  url
openurl 
  Title The effects of increased constant incubation temperature and cumulative acute heat shock exposures on morphology and survival of Lake Whitefish (Coregonus clupeaformis) embryos Type Journal Article
  Year (down) 2016 Publication Journal of Thermal Biology Abbreviated Journal J Therm Biol  
  Volume 57 Issue Pages 11-20  
  Keywords Climate change; Coregonus clupeaformis; Great Lakes; Heat shock; Morphology; Survival; Temperature; Thermal effluent  
  Abstract Increasing incubation temperatures, caused by global climate change or thermal effluent from industrial processes, may influence embryonic development of fish. This study investigates the cumulative effects of increased incubation temperature and repeated heat shocks on developing Lake Whitefish (Coregonus clupeaformis) embryos. We studied the effects of three constant incubation temperatures (2 degrees C, 5 degrees C or 8 degrees C water) and weekly, 1-h heat shocks (+3 degrees C) on hatching time, survival and morphology of embryos, as these endpoints may be particularly susceptible to temperature changes. The constant temperatures represent the predicted magnitude of elevated water temperatures from climate change and industrial thermal plumes. Time to the pre-hatch stage decreased as constant incubation temperature increased (148d at 2 degrees C, 92d at 5 degrees C, 50d at 8 degrees C), but weekly heat shocks did not affect time to hatch. Mean survival rates and embryo morphometrics were compared at specific developmental time-points (blastopore, eyed, fin flutter and pre-hatch) across all treatments. Constant incubation temperatures or +3 degrees C heat-shock exposures did not significantly alter cumulative survival percentage (~50% cumulative survival to pre-hatch stage). Constant warm incubation temperatures did result in differences in morphology in pre-hatch stage embryos. 8 degrees C and 5 degrees C embryos were significantly smaller and had larger yolks than 2 degrees C embryos, but heat-shocked embryos did not differ from their respective constant temperature treatment groups. Elevated incubation temperatures may adversely alter Lake Whitefish embryo size at hatch, but weekly 1-h heat shocks did not affect size or survival at hatch. These results suggest that intermittent bouts of warm water effluent (e.g., variable industrial emissions) are less likely to negatively affect Lake Whitefish embryonic development than warmer constant incubation temperatures that may occur due to climate change.  
  Call Number Serial 1227  
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Author Harada, N. file  url
openurl 
  Title Review: Potential catastrophic reduction of sea ice in the western Arctic Ocean: Its impact on biogeochemical cycles and marine ecosystems Type Journal Article
  Year (down) 2016 Publication Global and Planetary Change Abbreviated Journal Global and Planetary Change  
  Volume 136 Issue Pages 1-17  
  Keywords Arctic Ocean; Productivity; Biological pump; Marine ecosystem; Eddy; Climate change  
  Abstract The reduction of sea ice in the Arctic Ocean, which has progressed more rapidly than previously predicted, has the potential to cause multiple environmental stresses, including warming, acidification, and strengthened stratification of the ocean. Observational studies have been undertaken to detect the impacts on biogeochemical cycles and marine ecosystems of these environmental stresses in the Arctic Ocean. Satellite analyses show that the reduction of sea ice has been especially great in the western Arctic Ocean. Observations and model simulations have both helped to clarify the impact of sea-ice reductions on the dynamics of ecosystem processes and biogeochemical cycles. In this review, I focus on the western Arctic Ocean, which has experienced the most rapid retreat of sea ice in the Arctic Ocean and, very importantly, has a higher rate of primary production than any other area of the Arctic Ocean owing to the supply of nutrient-rich Pacific water. I report the impact of the current reduction of sea ice on marine biogeochemical cycles in the western Arctic Ocean, including lower-trophic-level organisms, and identify the key mechanism of changes in the biogeochemical cycles, based on published observations and model simulations. The retreat of sea ice has enhanced primary production and has increased the frequency of appearance of mesoscale anticyclonic eddies. These eddies enhance the light environment and replenish nutrients, and they also represent a mechanism that can increase the rate of the biological pump in the Arctic Ocean. Various unresolved issues that require further investigation, such as biological responses to environmental stressors such as ocean acidification, are also discussed.  
  Call Number Serial 1677  
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Author Boldt, B.R.; Kaufman, D.S.; McKay, N.P.; Briner, J.P. file  url
openurl 
  Title Holocene summer temperature reconstruction from sedimentary chlorophyll content, with treatment of age uncertainties, Kurupa Lake, Arctic Alaska Type Journal Article
  Year (down) 2015 Publication The Holocene Abbreviated Journal The Holocene  
  Volume 25 Issue 4 Pages 641-650  
  Keywords Chlorophyll; Summer temperature; Climate change; Temperature change; Holocene  
  Abstract Quantitative records of pre-industrial temperature changes are fundamental for understanding long-term natural climate variability. We used visible reflectance spectroscopy to measure chlorophyll content (and its derivatives) in a sediment core from Kurupa Lake, north-central Brooks Range, Alaska, to reconstruct summer temperature and the number of annual non-freezing days over the past 5.7 ka. A calibration-in-time approach was used to convert downcore changes in chlorophyll content to the climate variables, and an ensemble approach was used to integrate age and calibration uncertainties. The strongest correlation (rmedian=0.69, pmedian=0.02, RMSEP=1.9°C) is for summer (June through September) temperature using the 20th Century Reanalysis Project dataset. The chlorophyll-inferred 3-year-mean summer temperature shows that the warmest century (3.02.9 ka BP) was about 3.0°C (90% range of the ensemble members=2.34.0°C) higher and that the coldest century (1.41.3 ka BP) was about 5.5°C lower (90% range=7.6°C to 5.0°C) than during the reference period (AD 19611990). Century-to-century temperature changes over the past 5.7 ka at Kurupa Lake have been large (90% range=2.8°C to 3.1°C shifts in centennial mean), including the shift between the 19th and 20th centuries, which was above the 90th percentile of temperature changes across all representations of the reconstruction. In contrast to most Northern Hemisphere temperature reconstructions, Kurupa Lake shows no overall millennial-scale cooling trend. We suggest that increased summer duration (by 4.3 days during the last 6 ka) along with no long-term increase in sea-ice cover over the adjacent Chukchi Sea counter-balanced the influence of decreased insolation intensity on the aquatic productivity in Kurupa Lake.  
  Call Number Serial 1659  
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Author Bhattarai, B.; Beilin, R.; Ford, R. file  url
openurl 
  Title Gender, Agrobiodiversity, and Climate Change: A Study of Adaptation Practices in the Nepal Himalayas Type Journal Article
  Year (down) 2015 Publication World Development Abbreviated Journal World Development  
  Volume 70 Issue Pages 122-132  
  Keywords gender; agrobiodiversity management; climate change; adaptation; Nepal  
  Abstract Gender is seminal to agrobiodiversity management, and inequities are likely to be exacerbated under a changing climate. Using in-depth interviews with farmers and officials from government and non-government organizations in Nepal, we explore how gender relations are influenced by wider socio-economic changes, and how alterations in gender relations shape responses to climate change. Combining feminist political ecology and critical social-ecological systems thinking, we analyze how gender and adaptation interact as households abandon certain crops, adopt high-yielding varieties and shift to cash crops. We argue that the prevailing development paradigm reinforces inequitable gender structures in agrobiodiversity management, undermining adaptation to the changing climate.  
  Call Number Serial 1586  
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