"The same thing that is holding back climate change today will keep it going in the very long term, and that is the oceans," she says. The oceans are the ultimate "sink" for carbon and they absorb most of the heat. So even after atmospheric concentrations peak and very slowly start to decline (more slowly than you would think, she says), oceans will sustain the warming as it slowly re-releases heat back into the atmosphere.
One rationale for the study, she says, is to underscore the long-term nature of the changes humans are imposing on the climate system. Too often, research and policy is geared to what can or should be done by the end of this century. Among policymakers and the public, this can often look as though once that date is reached, problem solved.
Rather than a call to throw up one's hands in discouragement, she adds, the results show the importance of acting quickly to reduce emissions and so limit the very long-lived effects.
A focus on the big three
Solomon's group looked at three climate features: warming itself; changes in rain and snowfall patterns; and sea-level rise, absent any contribution from Greenland or Antarctic ice caps. (For a tidy summary, colleague Eoin O'Carroll has a tight post here.)
These three, the team says, involve aspects of climate where scientists have already identified some level of contribution from the effects of rising greenhouse-gas levels, where an understanding of the physical mechanisms driving the changes are well in hand, and where model projections are consistent despite other differences in the models.