If emissions of heat-trapping gases continue to accumulate in the atmosphere at the current rate, there may be many centuries of warming and a near-total loss of Arctic tundra, according to a new climate study.

Over all, the world would experience profound transformations, some potentially beneficial but many disruptive, and all at a pace rarely seen in nature, said the authors of the study, being published today in The Journal of Climate.

"The question is no longer whether we will need to address this problem, but when we will need to address the problem," said Kenneth Caldeira, an author of the study and a climate expert at the Carnegie Institution's Department of Global Ecology, based at Stanford University.

"We can either address it now, before we severely and irreversibly damage our climate, or we can wait until irreversible damage manifests itself strongly," Dr. Caldeira said. "If all we do is try to adapt, things will get worse and worse."