Global Warming: Forecasts by Scientists versus Scientific Forecasts

In 2007, the Intergovernmental Panel on Climate Change’s Working Group One, a panel of experts established by the World Meteorological Organization and the United Nations Environment Programme, issued its Fourth Assessment Report. The Report included predictions of dramatic increases in average world temperatures over the next 92 years and serious harm resulting from the predicted temperature increases. Using forecasting principles as our guide we asked: Are these forecasts a good basis for developing public policy? Our answer is “no”. To provide forecasts of climate change that are useful for policy-making, one would need to forecast (1) global temperature, (2) the effects of any temperature changes, and (3) the effects of feasible alternative policies. Proper forecasts of all three are necessary for rational policy making. The IPCC WG1 Report was regarded as providing the most credible long-term forecasts of global average temperatures by 31 of the 51 scientists and others involved in forecasting climate change who responded to our survey. We found no references in the 1056-page Report to the primary sources of information on forecasting methods despite the fact these are conveniently available in books, articles, and websites. We audited the forecasting processes described in Chapter 8 of the IPCC’s WG1 Report to assess the extent to which they complied with forecasting principles. We found enough information to make judgments on 89 out of a total of 140 forecasting principles. The forecasting procedures that were described violated 72 principles. Many of the violations were, by themselves, critical. The forecasts in the Report were not the outcome of scientific procedures. In effect, they were the opinions of scientists transformed by mathematics and obscured by complex writing. Research on forecasting has shown that experts’ predictions are not useful in situations involving uncertainly and complexity. We have been unable to identify any scientific forecasts of global warming. Claims that the Earth will get warmer have no more credence than saying that it will get colder

Stable carbon isotopes as potential sea-level indicators in salt marshes, North Carolina, USA

We compared the use of δ13C values and C:N ratios from salt-marsh sediments to reconstruct relative sea level (RSL) with an established approach using foraminifera. Analysis of bulk-organic sediment and plant samples collected along transects at two sites in North Carolina, USA demonstrates that sediment δ13C values can be used to distinguish between Spartina alterniflora-dominated low marsh (C photosynthetic pathway, δ13C values from —17.6‰ to 16.1‰) and Juncus roemerianus-dominated high marsh (C 3 photosynthetic pathway, δ13C values from —28.2‰ to —21.8‰) environments. Juncus roemerianus plants undergo little decompositional change in δ13C (average 0.8‰), although there is a clear difference between Spartina alterniflora tissue and bulk-organic sediments (approximately 4‰). C:N ratios on bulk-organic sediment from freshwater upland and salt-marsh environments converge during early diagenesis, rendering them of little use in reconstructing RSL. The utility of δ13C values as a sea-level indicator is limited by the elevational range of C4 plants, making it difficult to recognize salt-marsh subenvironments and improve the precision of RSL reconstructions. Furthermore, Juncus roemerianus-dominated high marsh and freshwater upland sediments cannot be adequately distinguished with δ13C values

Long-Term Trends in Loggerhead ( Caretta caretta

The Archie Carr National Wildlife Refuge (ACNWR), located along the central east coast of Florida (USA) in the western North Atlantic, hosts one of the largest loggerhead (Caretta caretta) nesting assemblages in the western Hemisphere. Sea turtle nesting activity has been continuously monitored on this beach for \u3e 31 yrs, representing one of the longest sea turtle reproductive data sets in the world. Between 1982 and 2012, an estimated 358,243 nests were deposited on the ACNWR with an estimated annual mean plus 95% confidence interval of 11,556 ± 1,129 nests. This constitutes 25.4% ± 0.8% of the mean annual Florida Index Nesting Beach Survey loggerhead complement. Mean annual clutch size was 113.9 ± 1.4, resulting in a 55.1% ± 4.0% mean annual hatching success rate and a mean emerging success rate of 53.3% ± 3.7%. The only egg-fate that was statistically correlated with emerging success were eggs washed out by erosion. The loss of eggs by erosion was significantly greater during storm and poststorm years, compared with nonstorm years. Among individual first-time nesting females that were measured, mean straight carapace length was 91.2 ± 0.15 cm and mean curved carapace length was 98.2 ± 0.15 cm. These data suggest that the ACNWR supports the greatest loggerhead nest density per kilometer in Florida, underscoring the importance of the ACNWR as one of the most important nesting habitats for loggerhead turtles in the Western Hemisphere