The drought that hit western North America from 2000 to 2004 was the most severe in the region in the last 800 years, according to a new study.

Get used to it.

That's the message of the research, published Sunday in the journal Nature Geoscience, which concludes that the exceptional turn-of-the-century drought could become "commonplace" by the end of this century.

By then, the worst droughts will make the 2000-2004 period seem like "an outlier of extreme wetness," the study's authors said, basing their assertion on climate model projections of future precipitation.

The results were surprising, said lead author Christopher Schwalm of Northern Arizona University. He and his colleagues analyzed satellite data, tree ring records and data from ground-monitoring stations to put the 2000-2004 drought in historical context.

"We were convinced that putting the five-year event in some historical context was important but had no idea what we'd find," he said. "Definitely a surprise to find we had an 800-year drought based on the tree-ring reconstructions."

Those tree-ring reconstructions suggest the recent drought was the most severe five-year drought since 1200, with only two events of similar magnitude between the years 800 and 1200: stretches between 977-981 and 1146-1151 that represent the worst portions of so-called megadroughts that persisted for decades.

Schwalm and his colleagues also examined the effect of the recent drought on western North America's role as a carbon sink.

According to their analysis, carbon uptake in the region declined by almost half during the early 2000s drought. They believe that if their projections for future drought hold, western North America could cease to act as a carbon sink by the end of the century.