Background
The authors write that "the effects of concurrent ocean warming and acidification on Antarctic marine benthos warrant investigation as little is known about potential synergies between these climate change stressors."

What was done
Ericson et al. "examined the interactive effects of warming and acidification on fertilization and embryonic development of the ecologically important sea urchin Sterechinus neumayeri reared from fertilization in elevated temperature (+1.5°C and 3°C) and decreased pH (-0.3 and -0.5 pH units)."

What was learned
Ericson et al. report that "fertilization using gametes from multiple males and females, to represent populations of spawners, was resilient to acidification at ambient temperature (0°C)," and they say that development to the blastula stage was "robust to levels of temperature and pH change predicted over coming decades."

What it means
The sea urchins studied by the seven scientists appear well equipped to successfully deal with IPCC-predicted near-future increases in seawater temperature and acidification; and whatever may happen beyond the current century should prove to be of little problem as well. Working with another sea urchin species (Strongylocentrotus franciscanus), for example, Sunday et al. (2011) found significant levels of phenotypic and genetic variation for larval size in future CO2 conditions; and they say that "a genetic basis for variation in CO2 responses has been found in the three previous studies in which it has been sought," citing the work of Langer et al. (2009), Parker et al. (2011) and Pistevos et al. (2011), which findings support the notion that "genetic variation exists at some level for almost all quantitative characters (Roff, 1997)."

References
Langer, G., Nehrke, G., Probert, I., Ly, J. and Ziveri, P. 2009. Strain-specific responses of Emiliania huxleyi to changing seawater carbonate chemistry. Biogeosciences 6: 2637-2646.

Parker, L.M., Ross, P.M. and O'Connor, W.A. 2011. Populations of the Sydney rock oyster, Saccostrea glomerata, vary in response to ocean acidification. Marine Biology 158: 689-697.

Pistevos, J.C.A., Calosi, P., Widdicombe, S. and Bishop, J.D.D. 2011. Will variation among genetic individuals influence species responses to global climate change? Oikos 120: 675-689.

Roff, D.A. 1997. Evolutionary Quantitative Genetics. Chapman and Hall, New York, New York, USA.

Sunday, J.M., Crim, R.N., Harley, C.D.G. and Hart, M.W. 2011. Quantifying rates of evolutionary adaptation in response to ocean acidification. PLoS ONE 6: e22881.