Well we are currently working with a model approach to the Cobb Douglas but where will include climatological variables so that allows us to measure the impact of climatic variations on production systems. I give you two links one is on rebicamcli network and the other is on the center where you can download some articles where some applications do. http://www.cyted.org/cyted_investigacion/detalle_accion.php?un=3b3dbaf68507998acd6a5a5254ab2d76 http://cicaea.unanleon.edu.ni/english_version/index_eng.html
There were interesting studies showing the effect of volcanic eruptions on stratospheric aerosols, the increase of diffuse light, and the resulting increase in plant productivity. See e.g.
Cohan, D. S., J. Xu, R. Greenwald, M. H. Bergin, and W. L. Chameides
(2002), Impact of atmospheric aerosol light scattering and absorption on
terrestrial net primary productivity, Global Biogeochem. Cycles, 16(4),
1090, doi:10.1029/2001GB001441.
Farquhar, G. D., and M. L. Roderick (2003), Pinatubo, diffuse light, and the
carbon cycle, Science, 299, 1997–1998.
Gu, L., D. Baldocchi, S. C. Wofsy, J. W. Munger, J. J. Michalsky, S. P.
Urbanski, and T. A. Boden (2003), Response of a deciduous forest to the
Mount Pinatubo eruption: Enhanced photosynthesis, Science, 299,
2035– 2038.
Gu, L. et al., 2002. Advantages of diffuse radiation for terrestrial
ecosystem productivity. J. Geophys. Res. 107D. doi:10.1029/
2001JD001242.
Lucht, W., et al. (2002), Climatic control of the high-latitude vegetation
greening trend and Pinatubo effect, Science, 296, 1687– 1689.
Roderick, M.L. et al., 2001. On the direct effect of clouds and atmospheric
particles on the productivity and structure of vegetation. Oecologia
Actually I did not spell the reference out but mentioned Mike Bergin to him see 1st entry. Also note that this question dates from the beginning of this year