Climate-related Environmental Changes Research Articles

Responding to Climate Change in Northern Communities: Impacts and Adaptations

... My approach to the issue of adaptation in northern communities is based on my experience working with the community of Sachs Harbour, Northwest Territories, and the project Inuit Observations of Climate Change (Riedlinger, 1999). The project is a collaborative research effort documenting Inuvialuit knowledge of climate change research. A secondary goal is to understand adaptive strategies used by the community to respond to climate change phenomena. Here, I describe how current climate-related environmental changes are affecting seasonal subsistence activity in Sachs Harbour and discuss how Inuvialuit are coping with such impacts.

Paleolimnological Reconstruction of Holocene Climatic Trends from Two Boreal Treeline Lakes, Northwest Territories, Canada

Paleolimnological analyses of two lakes located near the northern treeline in the central part of the Canadian Northwest Territories document a history of abrupt postglacial climatic and limnological changes. A diatom-based transfer function, based on weighted-averaging partial least squares regression (WA-PLS) techniques, was used to give quantitative estimates of past trends in lakewater dissolved organic carbon (DOC), a limnological variable strongly aligned with catchment vegetation and soils. The diatom record from the sediment cores provides evidence for profound limnologic change during the mid-Holocene, corresponding to maximum forest-tundra development between 5000 and 3000 14C yr BP in both Queen's and Toronto lakes, with a diatom-inferred relative change in lakewater DOC of up to 5.8 mg L–1 between the mid-Holocene and the present-day. Comparison of the diatom-inferred environmental changes with other proxy data (pollen, stable isotopes) from the same lakes provides strong evidence for an episode of climatic amelioration and lake responses to the associated vegetational changes (from tundra to forest-tundra) at sites near the central Canadian treeline. This study illustrates the usefulness of diatoms as quantitative indicators of past climate-related environmental change in northern treeline regions, and implies that aquatic ecosystems at high latitudes might respond with extreme sensitivity to climate warming.

Paleolimnological Reconstruction of Holocene Climatic Trends from Two Boreal Treeline Lakes, Northwest Territories, Canada

Paleolimnological analyses of two lakes located near the northern treeline in the central part of the Canadian Northwest Territories document a history of abrupt postglacial climatic and limnological changes. A diatom-based transfer function, based on weighted-averaging partial least squares regression (WA-PLS) techniques, was used to give quantitative estimates of past trends in lakewater dissolved organic carbon (DOC), a limnological variable strongly aligned with catchment vegetation and soils. The diatom record from the sediment cores provides evidence for profound limnologic change during the mid-Holocene, corresponding to maximum forest-tundra development between 5000 and 3000 14C yr BP in both Queen's and Toronto lakes, with a diatom-inferred relative change in lakewater DOC of up to 5.8 mg L–1 between the mid-Holocene and the present-day. Comparison of the diatom-inferred environmental changes with other proxy data (pollen, stable isotopes) from the same lakes provides strong evidence for an episode of climatic amelioration and lake responses to the associated vegetational changes (from tundra to forest-tundra) at sites near the central Canadian treeline. This study illustrates the usefulness of diatoms as quantitative indicators of past climate-related environmental change in northern treeline regions, and implies that aquatic ecosystems at high latitudes might respond with extreme sensitivity to climate warming.

River response to high-frequency climate oscillations in southern Europe over the past 200 k.y.

A 200 k.y. chronology of river response to climate-related environmental change has been established for northeast Spain using newly developed luminescence dating techniques. This constitutes the best-documented record of late Quaternary river behavior currently available for the North Atlantic region and enables fluvial stratigraphies to be compared with high-resolution ice core and marine oxygen isotope climate series. Pleistocene and Holocene river aggradational episodes coincide with stadial or neoglacial events, while phases of river incision occur during interstadial or interglacial periods. Alluviation and erosion cycles would appear to track variations in sediment supply controlled by vegetation cover and winter storm frequency.

The Paradox of Planned Weather Modification

A paradox has developed involving on one hand sizeable reductions during the last two years in federal support of weather modification, as opposed to major scientific-technical advances in the field plus strong recommendations for increased federal support from the scientific community. The major recent advances include the capability to operationally dissipate cold fogs, to enhance snow from orographic clouds, and to increase rain from tropical clouds, plus the discovery of sizeable urban-related increases in rainfall. Other advances include special weather radars, aircraft with new cloud sensors and the capability to penetrate thunderstorms, new seeding materials and delivery systems, and new techniques for evaluation of projects. These have been coupled with the spread of weather modification around the world and with the initiation of major seeding projects in Colorado (NHRE, HIPLEX, and San Juan Project), Florida, South Dakota, and Illinois-Missouri (METROMEX). Several groups (NACOA, NAS, ICAS, NWC, AMS) all made a series of positive recommendations for advancing the field through more federal support and reorganization. Yet, beginning in FY74, federal support for weather modification dropped 21% when other R&D increased 11%. Many possible causes for the paradox appear, including fear of weather changes, lack of scientific commitment, and a series of public, scientific, political, and military controversies. The three basic issues are that weather modification is still an immature technology; the socio-economic impacts are ill defined; and its management has been uncertain. Proper resolution of the paradox is more apt to occur either because of a dramatic scientific breakthrough or from growing concerns about weather and climate-related environmental changes.