No one would state that the everything in the natural world is perfectly optimized, but changes in climate are likely to alter then phenology of organisms in ways that the consequences are not understood. In response, the scientific community has monitored phenology for a long time--in some places hundreds of years--and conducted experiments to aid in forecasting future responses.
Published recently, Wolkovich et al. led a team that compared observed and experimental consequences of warming for phenology. Their conclusion was that experiments consistently underestimated the phenological consequences of warming.
Two commentaries were published along with the paper. Both sets of authors presented the case in defense of experiments that can be summarized as "nature is complicated".
Neither commentary undercuts the value of the work, but understanding the consequences of different types of warming and why phenology might not respond consistently to experimental warming underpins basic questions we have about the interactions between climate and the biotic world.
Wolkovich, E. M., B. I. Cook, J. M. Allen, T. M. Crimmins, J. L. Betancourt, S. E. Travers, S. Pau, J. Regetz, T. J. Davies, N. J. Kraft, et al. 2012. Warming experiments underpredict plant phenological responses to climate change. Nature 485:494-497.