Ring widths from trees on certain sites reflect climatic variation. Therefore, long time series derived from replicated and precisely dated ring -width chronologies may be utilized to extend climatic records into prehistoric times. Multivariate analyses of tree -ring chronologies from western North America are used to derive response functions from which one can ascertain what climatic information each ring -width chronology contains.In addition, multivariate analyses are utilized to calibrate a large number of ring -width chronologies of diverse response functions and from widely dispersed sites with a large number of regional climatic variables. A series of transfer functions are derived which allow estimates of anomalous climatic variation from tree -ring records.Reconstructions of anomalous variation in atmospheric circulation for portions of the northern hemisphere back to A.D. 1700 are obtained by applying the transfer functions to tree -ring data for time periods when ring data are available but climatic data are not.

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Long-term growth patterns of red spruce (Picea rubens Sarg.) were analyzed from increment cores collected from over 1000 trees at 48 sites in the eastern United States. Principal objectives were the evaluation of the distribution, timing, and uniqueness of observed patterns of decreasing radial growth during the past 25 years and the examination of stand competition and climate as factors contributing to observed changes.Our analyses focused on historical records of spruce mortality and approximately 200 years of radial growth data to search for historical precedents for current trends. In this work we have used time series analysis to detect the temporal frequency of significant negative or positive shifts in radial growth rates, an analysis of relationships between a stand competition index and observed changes in growth and mortality, and modeling of past growth-climate relationships to determine whether recent growth changes could be predicted based on climate.Collectively, these analyses indicate that the observed growth decreases of surviving red spruce trees at northeastern sites with high mortality have been anomalous during the past 20 to 25 years with respect to both historical annual growth patterns and past relationships to climate or stand development at these sites. In general, reductions in radial increment that have also been noted at southern high elevation sites but not at low elevations occurred 5 to 10 years later than at northern sites and represent less substantive departures from growth trends predicted by linear climate models.These results suggest that regional and not local stresses have triggered the observed decline in radial growth of red spruce at these sites. While climatic change may have contributed to observed changes, the degree of radial growth suppression observed is greater than would be expected based on past growth-climate relationships. This unique relationship of growth to climate suggests the influences of either recent, unique combinations of climatic stresses or the possibly interactive intervention of other regional-scale stresses, such as atmospheric pollution.

A B S T R A C T Time-series of estimated monthly carbon dioxide emissions from consumption of coal, petroleum and natural gas in the United States from 1981 to 2002 have been derived from energy consumption data. The data series for coal and natural gas each reveal a consistent seasonal pattern, with a winter peak for gas and two peaks (summer and winter) for coal. The annual cycle of total emissions has an amplitude of about 20 Tg-C, and is dominated by CO 2 released from consumption of natural gas. Summation of the monthly estimates to obtain annual values reveals good agreement with other estimates of CO 2 emissions. The varying proportions of CO 2 emitted from each fuel type over the course of a year lead to an annual cycle in the carbon isotope ratio (δ 13 C), with a range of about 2 ‰. These monthly carbon emissions estimates should be helpful in understanding the carbon cycle by providing (1) monthly/seasonal input for carbon cycle models, (2) estimates of the annual cycle of the 13 C isotope ratio in fossil-fuel CO 2 emissions and (3) data at fine enough time intervals to investigate effects of seasonal climate variations and changes in seasonally dependent use patterns of certain appliances (e.g. air conditioners) on fossil-fuel carbon emissions.

[1] Using a general-circulation climate model to drive an energy-use model, we projected changes in USA energy-use and in corresponding fossil-fuel CO 2 emissions through year 2025 for a low (1.2°C) and a high (3.4°C) temperature response to CO 2 doubling. The low-DT scenario had a cumulative (2003 -2025) energy increase of 1.09 quadrillion Btu (quads) for cooling/heating demand. Northeastern states had net energy reductions for cooling/ heating over the entire period, but in most other regions energy increases for cooling outweighed energy decreases for heating. The high-DT scenario had significantly increased warming, especially in winter, so decreased heating needs led to a cumulative (2003 -2025) heating/ cooling energy decrease of 0.82 quads. In both scenarios, CO 2 emissions increases from electricity generation outweighed CO 2 emissions decreases from reduced heating needs. The results reveal the intricate energyeconomy structure that must be considered in projecting consequences of climate warming for energy, economics, and fossil-fuel carbon emissions.