1000 Years of Climate Change

Bradley, R. S.

doi:10.1126/science.288.5470.1353

Cited by 116 publications

(39 citation statements)

References 23 publications

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“…Although the Arctic climate varies annually, decadally, and centennially (Walsh and Chapman, 1990;Appenzeller et al, 1998), global climate change is superimposing recent trends toward warmer temperatures and changes in snowfall (e.g., Maxwell, 1997;Bradley, 2000;Weller, 2000;P. Kyle and J. Ross, pers.…”

Section: Discussionmentioning

confidence: 99%

Catastrophic Die-off of Peary Caribou on the Western Queen Elizabeth Islands, Canadian High Arctic

Miller¹,

Gunn²

2003

ARCTIC

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ABSTRACT. The Peary caribou (Rangifer tarandus pearyi) is an endangered species in Canada, having been in an overall decline since 1961. Sightings of Peary caribou were compared from two aerial searches, in 1993 and 1998, on Bathurst and its neighbouring islands, western Queen Elizabeth Islands in the Canadian High Arctic. The comparison indicated a near-total (98%) cataclysmic decline in the number of Peary caribou seen per unit of search effort. In summer 1993, 2400 caribou were counted during 33.8 h of low-level helicopter searches. In contrast, in summer 1998, only 43 caribou were seen within the same area during 35.2 h of low-level helicopter searches. The frequency of observation was markedly different: 118.3 caribou/100 min in 1993, but only 2.0 caribou/100 min in 1998. The number of carcasses indicated that the decline resulted from deaths and not from mass emigration. Males died at a disproportionately higher rate than females among all 1+ yr old caribou, and bulls (4+ yr) compared to cows (3+ yr) had died at an even greater rate. Widespread, prolonged, exceptionally severe snow and ice conditions from 1994 -95 to 1996 -97 caused the die-off. Trends in snowfall are consistent with predictions for global warming in the western Canadian High Arctic. Future climate change may increase the frequency of years with unfavorable snow and ice conditions, which could prevent or at least impede future recovery of Peary caribou populations on the western Queen Elizabeth Islands, particularly to sizes that would support subsistence harvesting.Key words: Peary caribou, Rangifer tarandus pearyi, cataclysmic die-off, western Queen Elizabeth Islands RÉSUMÉ. Le caribou de Peary (Rangifer tarandus pearyi) est une espèce en péril au Canada, vu qu'elle a connu une diminution globale depuis 1961. On a comparé des observations du caribou de Peary faites lors de deux recherches aériennes menées en 1993 et 1998 sur l'île de Bathurst et les îles avoisinantes, celles de la Reine-Élisabeth occidentales dans l'Extrême-Arctique canadien. La comparaison a révélé un déclin cataclysmique quasi-total (98 %) du nombre de caribous de Peary aperçus par unité d'activité de recherche. En été 1993, on a dénombré 2400 caribous durant 33,8 heures de recherches par hélicoptère volant à basse altitude. En revanche, durant l'été 1998, on n'a aperçu que 43 caribous dans la même zone durant 35,2 heures de survol à basse altitude en hélicoptère. La fréquence des observations était nettement différente: 118,3 caribous/100 min en 1993, mais seulement 2,0 caribous/100 min en 1998. Le nombre de carcasses a démontré que le déclin était dû à la mort des animaux et non à une émigration massive. Les mâles mouraient à un taux supérieur à celui des femelles de façon disproportionnée parmi tous les caribous âgés de plus d'un an, et, en comparaison avec les femelles de plus de trois ans, les mâles de plus de quatre ans avaient péri à un taux encore plus élevé. La mortalité massive était due à des conditions d'enneigement et de glace généralisées et persistantes ...

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Section: Discussionmentioning

confidence: 99%

Catastrophic Die-off of Peary Caribou on the Western Queen Elizabeth Islands, Canadian High Arctic

Miller¹,

Gunn²

2003

ARCTIC

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“…The prevailing view of this interval, known commonly as the "Medieval Warm Period" (MWP), is that elevated temperatures were often only intermittently experienced and, in some regions, was apparently characterized instead by climatic anomalies such as prolonged drought, increased rainfall or a stronger monsoon system (Hughes and Diaz, 1994;Stine, 1994;Bradley et al, 2003;Zhang et al, 2008). However, evidence for the MWP being a global phenomenon is contentious, especially in the Southern Hemisphere, where there are few continuous, detailed palaeoclimatic records spanning this interval (Bradley, 2000;Broecker, 2001). Nevertheless, from the Marcacocha dataset we can infer that temperatures increased from ca.…”

Section: A Broader Contextmentioning

confidence: 99%

Putting the rise of the Inca Empire within a climatic and land management context

et al. 2009

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Abstract. The rapid expansion of the Inca from the Cuzco area of highland Peru (ca. AD 1400–1532) produced the largest empire in the New World. Although this meteoric growth may in part be due to the adoption of innovative societal strategies, supported by a large labour force and a standing army, we argue that it would not have been possible without increased crop productivity, which was linked to more favourable climatic conditions. Here we present a multi-proxy, high-resolution 1200-year lake sediment record from Marcacocha, located 12 km north of Ollantaytambo, in the heartland of the Inca Empire. This record reveals a period of sustained aridity that began from AD 880, followed by increased warming from AD 1100 that lasted beyond the arrival of the Spanish in AD 1532. These increasingly warmer conditions would have allowed the Inca and their immediate predecessors the opportunity to exploit higher altitudes (post-AD 1150) by constructing agricultural terraces that employed glacial-fed irrigation, in combination with deliberate agroforestry techniques. There may be some important lessons to be learnt today from these strategies for sustainable rural development in the Andes in the light of future climate uncertainty.

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“…D-ex values fluctuated on average between 10 and 14‰ (Figs 6 and 9a). The LIA appears to span the period 1400 to 1870 AD according to GISP2 chemical records in Europe (Mayewski and others, 1993;Meese and others, 1997;Bradley, 2000) and from ∼1500 AD in China (Li and Ku, 2002), which experienced lower temperatures compared with the 20th century. There are several minima with warming intervals during the LIA (Mayewski and others, 1993;Meese and others, 1997).…”

Section: Air Temperature and D-ex Valuesmentioning

confidence: 99%

Abrupt and moderate climate changes in the mid-latitudes of Asia during the Holocene

Aizen

Takeuchi

et al. 2016

J. Glaciol.

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ABSTRACT. A multiple parameter dating technique was used to establish a depth/age scale for a 171.3 m (145.87 m w.e.) surface to bedrock ice core (Bl2003) recovered from the cold recrystallization accumulation zone of the Western Belukha Plateau (4115 m a.s.l.) in the Siberian Altai Mountains. The ice-core record presented visible layering of annual accumulation and of δ Sulfate peaks coincident with volcanic eruptions, the Tunguska meteorite event, and the 1842 dust storm were used to verify dating. Analysis of the Bl2003 ice core reveals that the modern Altai glaciers were formed during the Younger Dryas (YD) (∼10 950 to ∼7500 cal a BC), and that they survived the Holocene Climate Optimum (HCO) (∼6500 to ∼3600 cal a BC) and the Medieval Warm Period (MWP) (∼640 to ∼1100 AD). A decrease in air temperature at the beginning and an abrupt increase at the end of the YD were identified. Intensification of winds and dust loading related to Asian desert expansion also characterized the YD. During the YD major ion concentrations increased significantly, up to 50 times for Na + (background), up to 45 times for Ca 2+ and Mg 2+ , and up to 20 times for SO 4 2− relative to the recent warm period from 1993 to 2003. A warm period lasted for about three centuries following the YD signaling onset of the HCO. A significant and prolonged decrease in air temperature from ∼2000 to ∼600 cal a BC was associated with a severe centennial drought (SCD). A sharp increase in air temperatures after the SCD was coincident with the MWP. After the MWP a cooling was followed gradually with further onset of the Little Ice Age. During the modern warm period an increase in air temperature is noted, which nearly reaches the average of HCO and MWP air temperature values.

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1000 Years of Climate Change

Cited by 116 publications

References 23 publications

Catastrophic Die-off of Peary Caribou on the Western Queen Elizabeth Islands, Canadian High Arctic

Catastrophic Die-off of Peary Caribou on the Western Queen Elizabeth Islands, Canadian High Arctic

Putting the rise of the Inca Empire within a climatic and land management context

Abrupt and moderate climate changes in the mid-latitudes of Asia during the Holocene

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