Oil will be toppled as North America's primary energy source this year, according to risk management firm DNV GL, with natural gas and electrification set to reshape the region's energy future.

The Norway-headquartered firm said Monday that overall energy demand in the U.S. and Canada would continue to decline over the coming months, as improving efficiencies in the transport sector dramatically reduce North America's reliance on oil.

"Energy efficiency is going to outpace the growth in GDP (gross domestic product), that's the main reason why energy demand is peaking," DNV GL's group president and CEO Remi Eriksen told CNBC's "Squawk Box Europe" on Monday.

"(And) there will be a massive change in technology in the transport sector, not only on the roads but also at sea," he added.

In a separate report published Monday by DNV GL, the company said "natural gas is set to overtake oil as the region's largest single energy source (this year) and remain the dominant source until 2050."