Climate change

About: Climate change is a research topic. Over the lifetime, 99222 publications have been published within this topic receiving 3572006 citations.

Global sea level linked to global temperature

Abstract: We propose a simple relationship linking global sea-level variations on time scales of decades to centuries to global mean temperature. This relationship is tested on synthetic data from a global climate model for the past millennium and the next century. When applied to observed data of sea level and temperature for 1880–2000, and taking into account known anthropogenic hydrologic contributions to sea level, the correlation is >0.99, explaining 98% of the variance. For future global temperature scenarios of the Intergovernmental Panel on Climate Change's Fourth Assessment Report, the relationship projects a sea-level rise ranging from 75 to 190 cm for the period 1990–2100.

Climate Change and Bark Beetles of the Western United States and Canada: Direct and Indirect Effects

Abstract: Climatic changes are predicted to significantly affect the frequency and severity of disturbances that shape forest ecosystems. We provide a synthesis of climate change effects on native bark beetles, important mortality agents of conifers in western North America. Because of differences in temperature-dependent life-history strategies, including cold-induced mortality and developmental timing, responses to warming will differ among and within bark beetle species. The success of bark beetle populations will also be influenced indirectly by the effects of climate on community associates and host-tree vigor, although little information is available to quantify these relationships. We used available population models and climate forecasts to explore the responses of two eruptive bark beetle species. Based on projected warming, increases in thermal regimes conducive to population success are predicted for Dendroctonus rufipennis (Kirby) and Dendroctonus ponderosae Hopkins, although there is considerable spatial and temporal variability. These predictions from population models suggest a movement of temperature suitability to higher latitudes and elevations and identify regions with a high potential for bark beetle outbreaks and associated tree mortality in the coming century.

Climate Change 1995

Abstract: Climate Change 1995 is a scientific assessment that was generated by more than 1 000 contributors from over 50 nations. It was jointly co-ordinated through two international agencies; the World Meteorological Organization and the United Nations Environment Programme. The assessment was completed by the Intergovernmental Panel on Climate Change (IPCC) with a primary aim of reviewing the current state of knowledge concerning the impacts of climate change on physical and ecological systems, human health, and socioeconomic factors. The second aim was to review the available information on the technical and economic feasibility of the potential mitigation and adaptation strategies.

Climate change and global water resources

Abstract: By 2025, it is estimated that around 5 billion people, out of a total population of around 8 billion, will be living in countries experiencing water stress (using more than 20% of their available resources). Climate change has the potential to impose additional pressures in some regions. This paper describes an assessment of the implications of climate change for global hydrological regimes and water resources. It uses climate change scenarios developed from Hadley Centre climate simulations (HadCM2 and HadCM3), and simulates global river #ows at a spatial resolution of 0.5]0.53 using a macro-scale hydrological model. Changes in national water resources are calculated, including both internally generated runo! and upstream imports, and compared with national water use estimates developed for the United Nations Comprehensive Assessment of the Freshwater Resources of the World. Although there is variation between scenarios, the results suggest that average annual runo! will increase in high latitudes, in equatorial Africa and Asia, and southeast Asia, and will decrease in mid-latitudes and most subtropical regions. The HadCM3 scenario produces changes in runo! which are often similar to those from the HadCM2 scenarios * but there are important regional di!erences. The rise in temperature associated with climate change leads to a general reduction in the proportion of precipitation falling as snow, and a consequent reduction in many areas in the duration of snow cover. This has implications for the timing of stream#ow in such regions, with a shift from spring snow melt to winter runo!. Under the HadCM2 ensemble mean scenario, the number of people living in countries with water stress would increase by 53 million by 2025 (relative to those who would be a!ected in the absence of climate change). Under the HadCM3 scenario, the number of people living in countries with water stress would rise by 113 million. However, by 2050 there would be a net reduction in populations in stressed countries under HadCM2 (of around 69 million), but an increase of 56 million under HadCM3. The study also showed that di!erent indications of the impact of climate change on water resource stresses could be obtained using di!erent projections of future water use. The paper emphasises the large range between estimates of ‘impacta, and also discusses the problems associated with the scale of analysis and the de"nition of indices of water resource impact. ( 1999 Elsevier Science Ltd. All rights reserved.

Human-Induced Changes in the Hydrology of the Western United States

Abstract: Observations have shown that the hydrological cycle of the western United States changed significantly over the last half of the 20th century. We present a regional, multivariable climate change detection and attribution study, using a high-resolution hydrologic model forced by global climate models, focusing on the changes that have already affected this primarily arid region with a large and growing population. The results show that up to 60% of the climate-related trends of river flow, winter air temperature, and snow pack between 1950 and 1999 are human-induced. These results are robust to perturbation of study variates and methods. They portend, in conjunction with previous work, a coming crisis in water supply for the western United States.