On March 20 2008, the Associated Press reporter Seth Borenstein published a news report titled “Global Warming Rushes Timing of Spring“. This article, unfortunately perpetuates the inaccurately narrow perspective that only “global warming” can produce an earlier greening up in the spring. Indeed, even though some areas are greening up later, the article has the audacity to write
” In much of Florida and southern Texas and Louisiana, the satellites show spring coming a tad later, and bizarrely, in a complicated way, global warming can explain that too, the scientists said.”
Thus, everything is attributable to “global warming”.
This inaccurate characterization of climate science ignores the following issues:
1. Plants only know about their immediate microclimate. They are not a metric of global warming, but only whether local conditions are conducive to earlier green-up. This can clearly occur due to landscape change in the vicinity of the plants, thus this issue needs to be considered in any explanation of changes in phenology.
2. The biogeochemical effect of higher atmospheric concentrations of CO2 (both in the background atmosphere, and, if in an urban or suburban region, the local enhancement of CO2 levels) can alter plant phenology. We found, for example, that the biogeochemical addition of added CO2 has a larger effect on temperatures and precipitation than the radiative effect of the added CO2 (in a regional model simulation);
Eastman, J.L., M.B. Coughenour, and R.A. Pielke, 2001: The effects of CO2 and landscape change using a coupled plant and meteorological model. Global Change Biology, 7, 797-815.
3. The biogeochemical effect of human caused nitrogen deposition can significantly effect plant responses including phenology. Nitrogen deposition is a major issue, as reported on Climate Science;
Further Evidence of the Role of Nitrogen Deposition as a First-Order Climate Forcing
Is Nitrogen Deposition a First-Order Climate Forcing?
4. Land fragmentation due to human land management is well known to alter bird, insect and other animal migration, reproductive and other activites as well as to introduce invasive species which significantly alter the local and regional ecosystems; e.g. see
Plant diversity- Another Climate Metric
If Seth Borenstein really wanted to do balanced news reporting, he would have addressed these other issues in his article, before advocating “global warming” as the cause for the change in phenology of vegetation in the spring. Instead, the AP news story is yet another example of the misuse of science to promote the inaccurately narrow perspective that global warming is the main culprit whenever an environmental change is observed.