Swedish and Canadian scientists say agriculture practices can lead to major disruptions of the world's water flows, with sudden and dire consequences.

Assistant Professor Line Gordon of Stockholm University in Sweden and Assistant Professors Garry Peterson and Elena Bennett of Montreal's McGill University argue global water management has been focused too much on the "blue water" side of the hydrological cycle, neglecting the largely invisible changes humanity has had on so-called "green water."

"Blue water is the part of the cycle we can see, like streams and rivers," Gordon said. "This is as opposed to 'green water' in soil moisture or evapotranspiration from plants, which agriculture can affect in significant ways."

The researchers looked at the likelihood of vital resilience being lost in the aftermath of catastrophic changes to the hydrological cycle that could be caused by agriculture and land-use practices.

"Our main point is that these effects aren't necessarily going to result in gradual change," said Peterson. "They can result in surprising, dramatic changes, what we call 'ecosystem flips' or 'ecosystem regime changes,' which can be very difficult or even impossible to reverse."

The subject will be discussed April 14-17 in Stockholm during the 2008 Resilience Conference.