Climatic trends from isotopic records of tree rings: The past 100?200 years

Abstract

There has been a great deal of discussion about global warming from accumulation of anthropogenic greenhouse gases in the atmosphere (Houghton et al., 1990). Relatively less attention has been paid to spatial and]or temporal climatic variations that may be associated with a warmer climate (Rind et al., 1989) or with anthropogenic activities (Schneider, 1994). In this article, we show that an increase in climatic variability may have started. Fourteen isotopic time series of tree rings are presented. These trees were randomly collected from world-wide locations and cover time periods of 120 to over 200 years. The isotopic records show increasing 6D values that suggest a consistent and progressive warming occurred in the 19th century in all locations where the trees were sampled. The rate of warming is greater at relatively cold locations than at warm locations with two exceptions. The records also suggest greater climatic variations both temporally and spatially in the 20th century than in the 19th century.

Summer maximum temperature in northern France over the past century: instrumental data versus multiple proxies (tree-ring isotopes, grape harvest dates and forest fires)

“…The dependence of δ 18 O and δD on temperature and relative humidity is in agreement with previous results (Burk and Stuiver 1981;Edwards et al 1985;Buhay and Edwards 1995;Feng and Epstein 1996;Baillie et al 2000;Raffalli-Delerce et al 2004;Szczepanek et al 2006). Local temperature has an indirect influence on cellulose δ 18 O and δD, via the precipitation δ 18 O or δD relationship with temperature, but modulated through the evaporation of leaf water.…”

Recent climatic trends in nearshore water temperatures in the St. Lawrence Great Lakes

“…Observational evidence for global warming centers on long-term temperature records (Hansen and Lebedeff 1988;Wigley et al 1989) and proxy climate variables, which infer historical global temperatures based on ice core analyses (Barnola et al 1987), tree ring data (Feng and Epstein 1996), bore hole temperatures, and the retreat of mountain glaciers (Ott 1997). At the same time, new insights suggest that much of the observed warming may be partially explained by a reduction in the diurnal temperature range for most parts of the world (Easterling et al 1997).…”

The Role of Stable Isotopes in Geochemistries of All Kinds

“…Our findings suggest that warming had taken place in the nineteenth century, whereas somewhat more erratic climatic records were observed for the twentieth century (Feng & Epstein 1996). In this connection, we have been able to obtain information from fragments of wood that are thousands of years old.…”