Background
The authors write that "climate change is predicted to increase average air surface temperatures by several degrees in this century," and that "species exposed to changes in the environmental conditions may first show plastic phenotypic responses (e.g. Rehfeldt et al., 2002); but, in the long term, rapid climate change raises the question how quickly species can evolutionarily adapt to future climates in their habitats."

What was done
Kuparinen et al., as they describe it, "investigate the adaptation of Scots pine (Pinus sylvestris) and Silver birch (Betula pendula) to climate change induced prolongation of the thermal growing season," using "quantitative genetic individual-based simulations to disentangle the relative roles of mortality, dispersal ability and maturation age for the speed of adaptation."

What was learned
The three scientists say their simulations predict that "after 100 years of climate change, the genotypic growth period length of both species will lag more than 50% behind the climatically determined optimum," but that "this lag is reduced by increased mortality of established trees," in conformity with the prior suggestion of Savolainen et al. (2004) and Kramer et al. (2008) that "the persistence of maladapted old trees preventing the establishment of seedlings better adapted to a changed environment" is not helpful to their long-term survival. Indeed, it is not only not helpful; it is detrimental!

What it means
In light of the fact that Kuparinen et al.'s findings suggest, as they put it, that "adaptation might be sped up if mortality factors such as storms, fires, or insect outbreaks get more common in the future," it could actually turn out to be a positive thing -- in this particular instance, at least, and for these specific species -- if some of the presumed negative climate-alarmist-envisioned consequences of global warming were to become a reality.

References
Kramer, K., Bulteveld, J., Forstreuter, M., Geburek, T., Leonardi, S., Menozzi, P., Povillon, F., Scherlhaas, M.J., Teissier du Cros, E., Vendramin, G.G. and van der Werf, D.C. 2008. Bridging the gap between ecophysiological and genetic knowledge to assess the adaptive potential of European beech. Ecological Modelling 216: 333-353.

Rehfeldt, G.R., Tchebakova, N.M., Parfenova, Y.I., Wykoff, W.R., Kuzmina, N.A. and Milyutin, L.I. 2002. Intraspecific responses to climate change in Pinus sylvestris. Global Change Biology 8: 912-929.

Savolainen, O., Bokma, F., Garcia-Gil, R., Komulainen, P. and Repo, T. 2004. Genetic variation in cessation of growth and frost hardiness and consequences for adaptation of Pinus sylvestris to climatic changes. Forest Ecology and Management 197: 79-89.