VANCOUVER, BC-A 110-page report by an international team of
climate experts published today by the independent Fraser
Institute examines critically-important scientific evidence
that has been overlooked or omitted in government reports that
blame climate change on carbon dioxide emissions.
The report, Critical Topics in Global Warming, supplements the Fraser Institute's Independent Summary for Policymakers, a 2007 analysis of the United Nations' Intergovernmental Panel on Climate Change Fourth Assessment Report.
The new peer-reviewed report's seven chapters investigate
published scientific literature on issues such as the effects
of ocean oscillations and solar variations on climate,
historical climate variability, statistical challenges in
climate analysis, uncertainties in climate modeling, and
quality problems in temperature measurement systems. The report
leaves no doubt that the science is far from "settled" on
The new report reviews published evidence demonstrating such
critically important points as:
- Natural oscillations of the Pacific and Atlantic
oceans-not increasing levels of greenhouse gases in the
atmosphere-explain 20th century weather changes in the United
States, Greenland, and the Arctic, as well as the reduction
of Arctic sea ice.
- Arctic air temperatures over the last century correlate
better with average incoming solar radiation than levels of
atmospheric carbon dioxide.
- Evidence from around the world reveals climatic
conditions in the Medieval era were warmer than the recent
era. As the report states: "Late 20th century temperatures
are not unprecedented, falling well within the range of
natural millennial-scale variability, particularly in
comparison to the interval 1,000 years ago when there was 25
per cent less carbon dioxide in the air than there is
- The popularized notion that carbon dioxide "traps heat"
in the atmosphere, thereby raising temperatures as in a
greenhouse, is inaccurate. As the report states: "The
atmosphere does not actually work like a greenhouse …Unlike
the greenhouse case, whether or not temperature changes, and
how it changes, depends on the details. And the details
cannot be determined from first principles."
- Extensive problems in the global weather station network,
including urbanization near the thermometers and a sharp loss
of monitoring sites in the early 1990s, indicate the
likelihood of an upward bias in many published global surface
- Climate trend analysis has been skewed by a failure to
properly account for long-term persistence. New statistical
modeling work has challenged the view that recent trends are
outside natural variability.
- Computer-based climate modeling has contributed to our
understanding of the climate, but it is insufficient as the
basis of global warming theory. Too much emphasis on modeling
discourages scientists from pursuing alternative,
complementary scientific strategies that are essential for