Antarctic Ice Cores Essay

Submitted By shayla106
Words: 580
Pages: 3

There are a few scientific errors that are important in the film. At one point Gore claims that you can see the aerosol concentrations in Antarctic ice cores change "in just two years", due to the U.S. Clean Air Act. You can't see dust and aerosols at all in Antarctic cores -- not with the naked eye -- and I'm skeptical you can definitively point to the influence of the Clean Air Act. I was left wondering whether Gore got this notion, and I hope he'll correct it in future versions of his slideshow. Another complaint is the juxtaposition of an image relating to CO2 emissions and an image illustrating invasive plant species. This is misleading; the problem of invasive species is predominantly due to land use change and importation, not to "global warming". Still, these are rather minor errors. It is true that the effect of reduced leaded gasoline use in the U.S. does clearly show up in Greenland ice cores; and it is also certainly true that climate change could exacerbate the problem of invasive species.
Several of my colleagues complained that a more significant error is Gore's use of the long ice core records of CO2 and temperature (from oxygen isotope measurements) in Antarctic ice cores to illustrate the correlation between the two. The complaint is that the correlation is somewhat misleading, because a number of other climate forcings besides CO2 contribute to the change in Antarctic temperature between glacial and interglacial climate. Simply extrapolating this correlation forward in time puts the temperature in 2100 A.D. somewhere upwards of 10 C warmer than present -- rather at the extreme end of the vast majority of projections (as we have discussed here). However, I don't really agree with my colleagues' criticism on this point. Gore is careful not to state what the temperature/CO2 scaling is. He is making a qualitative point, which is entirely accurate. The fact is that it would be difficult or impossible to explain past changes in temperature during the ice age cycles without CO2 changes (as we have discussed here). In that sense, the ice core CO2-temperature correlation remains an appropriate demonstration of the influence of CO2 on climate.

For the most part, I think Gore gets the science right, just as he did in Earth in the Balance. The small errors don't detract from…