CALGARY — The sheer number of Hummer urban assault vehicles crowding the roads -- reminiscent of the ostentatious Cadillacs of the heyday 1970s -- leaves little doubt that boom times have returned to Alberta.

Gas guzzlers, mega-houses and lavish spending are signs of what several years of record oil and natural gas prices have done to Canada's oilpatch epicentre.

In some ways, this is an encore performance after the first major oil boom 30 years ago, when events around the world and an inflexible oil supply sent prices soaring.

"The cause of these current higher prices and energy boom, compared to last time around, are actually pretty similar, despite what some people think,'' says Vince Lauerman, a global energy analyst with the Canadian Energy Research Institute.

The run-up in oil prices through the 1970s and early '80s pumped Alberta full of cash and optimism before recession and witheringly low crude prices knocked the province to its knees.

The hangover from last time means people appreciate the boom-and-bust volatility of the petro-economy, particularly in Calgary head offices, where multibillion-dollar investment deals are made.

Sure, the cost of oilsands projects have soared of late, but eye-popping price tags tend to be based on oil in the $40 US per barrel range, not current levels of $75 US and higher.

"I look around and see people holding their breaths, thinking `This can't last much longer, we've been through this,' '' says Greg Stringham, vice-president of markets for the Canadian Association of Petroleum Producers.

"They're saying that the costs are creeping up, but we've got to try to beat them back down because we know the price of oil's coming back down.

"We've got to prove these oilsands plants at lower prices than what they currently are today.''

Just how low can oil fall these days? Within that question lies the key difference between the two oil booms.

Over the past two decades, major shifts have occurred:

• The Organization of the Petroleum Exporting Countries, which played a key role last time, exerts far less control today and supplies only 40 per cent of the world's oil.
• Last boom-time, major fields like the North Sea and Alaska were ready to produce. Today the growth areas -- including Alberta's oilsands -- are far slower to develop.
• Emerging nations such as China, India and Brazil are ramping up oil consumption, adding demand that wasn't there in the 1970s.
• Most developing countries were running big current account deficits 30 years ago, so when oil prices rose, they got hammered, says Lauerman. Now most major, developing, oil-importing countries have large current account surpluses and can afford to pay a premium.

Throw in the fact that oil reserves that are easy to tap have been gobbled up, and you have a simple equation: Diminishing global supply plus voracious demand equals the days of cheap oil are probably gone for good.

That means places with large remaining oil reserves, such as Alberta, will enjoy longer booms, and the busts are unlikely to ever dip as low as they once did.

Louis Theriault, director of economic forecasting for the Conference Board of Canada, believes oil will remain above $60 US per barrel to the end of the decade.

The sustainability of the boom, he says, is due to the sustainability of the demand.

Even Saudi Arabia can't simply pump more oil to sate demand. "The problem is OPEC can't open the tap anymore,'' says Theriault. "Because the stream in the tap is pretty weak at the moment.''

What's more, traders, acting on every piece of geopolitical news -- related to oil production or not -- help instil a "fear premium'' into the market.

And the energy sector is looking to fields once considered marginal to add supplies at much higher cost.

There's upwards of $100 billion in international investment money earmarked over the next decade for oilsands development, which is almost certain to prolong the Alberta boom.

Still, there's always that one dark cloud -- the very real possibility of a global downturn, or even a recession.

Sustained oil prices are finally starting to feed into core inflation and forcing the world's central banks to raise interest rates.

This acts as a brake on the economy.

But even with a slowdown, the price of oil is not likely to fall much below $40 US per barrel, says Lauerman.

"This boom is going to be more sustainable than the last boom. But at the same time, along the way, we're bound to see some glitches.''