February 28, 2007
GCRIO Program Overview
Our extensive collection of documents.
Archives of the
Global Climate Change Digest
A Guide to Information on Greenhouse Gases and Ozone Depletion
Published July 1988 through June 1999
FROM VOLUME 10, NUMBER 4, APRIL 1997
GENERAL INTEREST AND POLICY
"The Use and
Abuse of Climate Models," K.E. Trenberth (Clim. Analysis Sect., NCAR, POB 3000,
Boulder CO 80307; e-mail: firstname.lastname@example.org), Nature, 386(6621),
131-133, Mar. 13, 1997.
A commentary giving a detailed but non-technical explanation of the rationale for using
mathematical models, despite their inherent limitations, to understand global climate
change, and their contribution to formulating policy. Opinion is polarized as to the value
of such models in projecting future climate; the truth lies in between. Many-but not
all-models are very useful, but their results must be interpreted properly.
Discusses model errors and how they can be minimized or circumvented to obtain useful
information; model validation; and future developments in modeling. Concludes with a
summary of the IPCC projections of future global warming by greenhouse gases. Such
projections cannot offer uncertainty, but they are far better than declaring ignorance and
saying nothing at all. The debate over what, if any, remedial action the world should take
must be based on an appreciation of both the strengths and the weaknesses of climate
Trends in Satellite MSU Temperatures from Merging Different Satellite Records," J.W.
Hurrell (NCAR, POB 3000, Boulder CO 80307) and K.E. Trenberth, ibid., 164-167.
(See NEWS, this Global Climate Change Digest issue--Apr. 1997.) The trends in
global temperature for the period 1979-1995 inferred from surface observations (warming)
and from satellite measurements (cooling) are at odds with each other, and have been a
matter of spirited debate. The satellite record for this period consists of nine different
segments from different instruments, each with its own error characteristics. This study
investigates the implications of the lack of a single satellite record on the derived
temperature trend. Because the temperature measured by the satellite instruments is
heavily influenced by sea surface temperatures (SSTs), the authors make statistical
inferences about the satellite temperature record by generating equivalent satellite
temperatures using an atmospheric general circulation model forced with observations of
tropical SSTs. Results strongly suggest that two spurious downward jumps in the satellite
record occurred coincident with changes of instruments during the period, and that the
real temperature trend is likely to be small but positive.
Level Rise Soon from West Antarctic Ice Sheet Collapse?" C.R. Bentley (Geophys. &
Polar Res. Ctr., Univ. Wisconsin, Madison WI 53706; e-mail: email@example.com), Science,
275(5303), 1077-1078, Feb. 21, 1997.
A glaciologist comments on theoretical and observational evidence that the West
Antarctic Ice Sheet could collapse, with a subsequent rapid rise in sea level. Cites
evidence of stability in the recent past, to conclude that it is difficult to see how
climate warming (whether anthropogenic or natural) could trigger a collapse in the next
century or two. It is questionable whether ice shelf thinning would have any drastic
effect on the inland ice.
Decoupling of Terrestrial Carbon and Nitrogen Cycles," G.P. Asner (CIRES, Univ.
Colorado, Boulder CO 80309), BioScience, 47(4), 226-232, Apr. 1997.
Reviews how human influences on land cover and nitrogen supply are altering natural
biogeochemical links in the biosphere, and how the terrestrial carbon cycle will respond
to and influence changes in atmospheric CO2 and temperature. Although elevated
levels of nitrogen and CO2 are stimulating the uptake of anthropogenic CO2,
the effect is only temporary. The rapidly changing global nitrogen cycle, with its
increasing nitrogen depositon, can also lead to increases in greenhouse gases such as
methane, nitrous oxide, and tropospheric ozone, which counterbalance the uptake of CO2.
As natural linkages between the terrestrial carbon and nitrogen cycles continue to
deteriorate in coming decades, such changes are likely to become even more pronounced.
Science Under Siege in the U.S. Congress," G.E. Brown Jr. (U.S. House of
Representatives, Washington DC 20515), Environment, 39(2), 12-20, 29-31,
The author, the ranking Democratic member of the U.S. House Committee on Science, draws
from and comments on a series of Congressional hearings on three key environmental issues:
global climate change, ozone depletion, and dioxin health risks. He argues that the
testimony offered by skeptic scientists during these hearings presents a distorted
interpretation of the environmental science underlying policy and research funding
decisions, and it reflects a troubling devaluation of the process of peer review. Suggests
that scientists must do a better job of educating the public, and find new ways to respond
to the arguments of skeptics given the rapid-fire political process, so that the proper
balance between policy and science can be restored.
Change and Social Justice," F.O. Hampson (Intl. Affairs, Carleton Univ., Ottawa,
Can.), J. Reppy, ibid., 39(3), 12-15 ff, Apr. 1997.
Outlines some of the moral dilemmas created by climate change and provides an overview
of different approaches to those dilemmas. To achieve social justice we not only need
guidelines for moral reasoning, but also need to analyze the distribution of political and
economic power and to think critically about the use of other sources of authority, such
as scientific knowledge. The central question for social justice is, "Who
counts?" Only after we have answered this question can we begin to construct
responsible solutions to the practical problems posed by climate change.
Guide to Publishers
Index of Abbreviations