How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

Modelling the Long (MAM) and Short (OND) Rains of East Africa

Paper Reviewed
Yang, W., Seager, R., Cane, M.A. and Lyon, B. 2014. The East African long rains in observations and models. Journal of Climate 27: 7185-7202.

In introducing their study, Yang et al. (2014) write that "decadal variability of the East African precipitation during the season of March-May (long rains) is examined and the performance of a series of models in simulating the observed features is assessed," which effort also included doing the same for the season of October-December (short rains). And what did the examination and simulation reveal?

The four researchers report "the multi-model mean of the fully-coupled models of the CMIP5 historical experiment underestimates the East African long rains and overestimates the short rains with a considerable range of performance among the individual models." And they say that "this lack of coupled model skill casts doubt on projections of future East African precipitation and on the use of these models to understand past variations," as has also been suggested by the work of Tierney et al. (2013).

In light of these findings, Yang et al. conclude "it should not be assumed that recent drying trends represent an anthropogenically-forced precipitation change and that the trends will continue." Nor, as they continue, "should it be assumed that the model projection of wetting in response to rising greenhouse gases is correct." Indeed, they say "we are distressingly far from an adequate understanding or a usable ability to model climate variability and change in this socially critical region." And that is a pretty sad summation of an enterprise that has gobbled up billions of tax dollars with nothing to show for it.

Tierney, J.E., Smerdon, J.E., Anchukaitis, K.J. and Seager, R. 2013. Multidecadal variability in East African hydroclimate controlled by the Indian Ocean. Nature 493: 389-392.

Posted 4 February 2015