Archives of the
Global Climate Change Digest
A Guide to Information on Greenhouse Gases and Ozone Depletion
Published July 1988 through June 1999

"Analyzing Ultraviolet-B Radiation: Is There a Trend?" Comment by P.J. Michaels (Dept. Environ. Sci., Univ. Virginia, Charlottesville VA 22903), S.F. Singer, P.C. Knappenberger; and reply by J.B. Kerr (Atmos. Environ. Serv., 4905 Dufferin St., Downsview ON M3H 5T4, Can.), C.T. McElroy, Science, 264(5163), 1341-1343, May 27, 1994.

Michaels et al. perform a statistical analysis of the observations of UV-B published last November by Kerr and McElroy (GCCD, p. 2, Nov. 1993), concluding that the upward trend they found from 1989 to 1993 is an artifact of the analysis. Kerr and McElroy respond here with criticism of the approach of Michaels et al., reaffirming that their data shows evidence of increasing UV-B associated with the documented decline in ozone since 1980.

"Recent Warming in Global Temperature Series," P.D. Jones (Clim. Res. Unit, Univ. E. Anglia, Norwich NR4 7TJ, UK), Geophys. Res. Lett., 21(12), 1149-1152, June 15, 1994.

Compares estimates of global temperature trends over the period 1979-1993 by comparing data from three sources: surface measurements, radiosonde measurements of the lower atmosphere, and satellite observations. The three records show marked differences, which can be explained by the short record length and the transitory nature of volcanic and El Niño/Southern Oscillation effects. Correction for these effects yields a temperature rise of about 0.1°C per decade since 1958. This relatively small trend compared to current modeling expectations of an enhanced greenhouse effect may reflect the offsetting influences of natural variations and cooling by sulfate aerosols.

"Increasing U.S. Streamflow Linked to Greenhouse Forcing," H.F. Lins (U.S. Geol. Survey, Reston, Va.), P.J. Michaels, Eos, 75(25), 281, 284-285, June 21, 1994.

Analysis of climate-sensitive streamflow data recently collected by the USGS shows increasing trends in monthly streamflow during the past five decades across most of the conterminous U.S. This result supports the hypothesis that enhanced greenhouse forcing produces an enhanced hydrologic cycle, at least during autumn and winter months.

"Climate and Environmental Change at High Northern Latitudes," L. Kullman (Dept. Phys. Geog., Umeå Univ., S-901 87 Umeå, Swed.), Progr. Phys. Geog., 18(1), 124-135, 1994.

A selective review of research developments over the past year undertaken to evalute topical environmental issues of public and scientific concern against established facts. Examines the cryosphere and vegetation and finds no evidence of predicted impacts of an enhanced greenhouse effect. The scientific basis for costly global regulations to influence climate is virtually nonexistent.

"Climate Effects on Mountain Plants," G. Grabherr (Dept. Vegetation Ecol., Univ. Vienna, POB 285, A1091 Vienna, Austria), M. Gottfried, H. Pauli, Nature, 369(6480), 448, June 9, 1994.