Prime Minister Stephen Harper waves as he arrives at the Calgary Southwest riding association barbecue in Calgary on Sunday, when he was joined by fellow Conservatives. (Jeff McIntosh/Canadian Press)

Prime Minister Stephen Harper, fresh off the G8 leaders meeting in Japan where talks focused on the environment, arrived at his home base in Calgary and wasted no time in attacking the Opposition Liberals' green plan.

Dressed in a Stetson and a checkered cowboy shirt, Harper told a crowd of Conservative party faithful Sunday night at a Calgary Stampede barbecue that Liberal Leader Stéphane Dion's plan to shift taxes toward carbon-emitting industries and away from individuals would devastate the Canadian economy.

"Dion's carbon tax is not an environmental policy. It is just a wealth redistribution program disguised as an environmental policy," Harper said.

Dion's plan, called the Green Shift, would deliver $15 billion in broad-based income tax cuts to Canadians facing higher energy and goods prices as a result of new taxes on domestic industries that produce high carbon emissions.

"It will stop the economic progress of the Canadian middle class dead in its tracks and it will make the cost of living unbearable for fixed-income seniors and low-income seniors," Harper told the crowd in his Calgary Southwest riding.

Global carbon emissions were a major focus of the Group of Eight summit in Toyako, Japan, that ended last week. World leaders, including Harper, endorsed the idea of halving global carbon emissions by 2050.

Attending his third Calgary Stampede as prime minister, Harper also repeated his party's pledge to deal with the "escalating problem of violent youth crime" when Parliament resumes in the fall.

"We must send a message — and we will — that we hold young lawbreakers responsible for their behaviour. That is what we intend to do this coming session."

Recent Statistics Canada figures show that while overall youth crime is down significantly in the past 15 years, violent crime involving 12- to 17-year-olds has surged 30 per cent since 1991.

With files from the Canadian Press