David Suzuki is urging Nova Scotians to tell Ottawa to make the environment a priority.

Suzuki, one of Canada's best-known environmentalists, was in Halifax Thursday as part a cross-country tour he is undertaking, asking people what they would do about the environment if they were prime minister for the day.

"I would say that we are in a state of crisis, that it's the equivalent of 100 Pearl Harbours going off at once in the environment," he said.

A United Nations report released Friday said human activity was "very likely" the cause of global warming and that higher temperatures and rising sea levels would continue for centuries, regardless of reductions in greenhouse gas emissions.

Suzuki criticized the federal government for not supporting the Kyoto Accord, which set deadlines for reducing carbon emissions into the atmosphere.

"We can't continue to indulge in campaign or political rhetoric," he said. "We've got to commit the government to concrete reduction targets, deep reductions, and we have to get corporations and everyone to meet those targets."

In Nova Scotia, parched farmland and eroding shorelines are just two of the effects of global warming.

More dry spells are predicted as temperatures rise, said Rob Gordon, Canada Research Chair in Agriculture Resources Management at the Nova Scotia Agricultural College in Truro.

'Huge increases' in water demand

"There's going to be huge increases in the amount of water that's going to have to be used to meet sustainable crop and production needs," he told CBC News Friday.

For farmers, this means a greater focus on supplemental irrigation, but Gordon said the problem extends to anyone who needs water to drink or even to fish in.

And the issue isn't just about the amount of precipitation, he said, noting global warming leads to more frequent extreme events like hurricanes and floods and extended mild periods.

"Some of these extreme conditions … makes it very difficult to be able to manage our systems effectively and maintain economically viable farms," Gordon said.

"There's a lot of issues that producers need to deal with, and it's getting more and more difficult."

Buildings and wharves along the shore are also at risk as sea levels rise and storm surges become more frequent.

Halifax architect John Crace, an expert on environmentally friendly buildings, said the damage could go beyond that, with salt water getting into well water and septic fields flooding.