Whether BP's oil spill in the Gulf of Mexico results in a moratorium on offshore drilling is far from certain, but there is little doubt the rules governing deepwater exploration are going to become much tougher.

"Clearly, there is a need to put in place all the risk mitigation measures that are possible," Richard Martin, president of Montreal-based Alcera Consulting, which advises companies on risk management strategies, told CBC News.

Windy conditions have so far made oil booms largely ineffective at containing the Gulf of Mexico oil slick. (Sean Gardner/Reuters)

Martin said he doesn't see a moratorium as necessary and favours continued offshore oil exploration to meet the world's energy needs. But he said it's clear the BP spill could have been foreseen and measures to prevent it could have been put in place.

On April 2, just a month before the BP drill rig exploded in the Gulf, U.S. President Barack Obama announced his government would begin leasing some areas off the coasts of Virginia, Alaska and possibly Florida to oil companies for drilling.

Then Obama said: "It turns out, by the way, that oil rigs today generally don't cause spills. They are technologically very advanced."

Last week, however, White House adviser David Axelrod told ABC's Good Morning America that "no domestic drilling in new areas is going to go forward until there is an adequate review of what's happened [in the Gulf of Mexico] and of what is being proposed elsewhere."

Philip Radford, the Greenpeace executive director, called that "a welcome first step" but said it does not go far enough.

"The only way to prevent human, economic and environmental tragedies like the BP deepwater disaster," Radford said, "is to re-enact the moratorium on offshore drilling and to replace dirty dangerous fuels with clean energy."

New offshore drilling in most U.S. waters was banned in the early 1980s, after a disastrous oil spill off the California coast in 1969.

But some in the industry have called for the lifting of a moratorium on drilling off the B.C. coast, and drilling is already allowed in Canada's Beaufort Sea. Another project that could come in for environmental criticism is Calgary-based Enbridge's proposed 1,170-kilometre pipeline from the Alberta oilsands to a tanker terminal proposed for Kitimat, on the B.C. coast.

The BP spill could end up being worse than the leak of 41.6 million litres of crude into Alaska's Prince William Sound from the Exxon Valdez in March 1989. (Jack Smith/Associated Press)

Exploration off B.C. won't likely happen if the spill off the Louisiana coast ends up being the worst in U.S. history.

No one knows exactly how much oil is leaking, but the best guess at present — based on BP and U.S. Coast Guard estimates — is that the total will be about a third of the 41.6 million litres of crude that leaked from the supertanker Exxon Valdez into Alaska's Prince William Sound in 1989. That incident now holds the dubious distinction of being the worst U.S. spill.

However, if the Louisiana cleanup takes the full 90 days that BP officials have said might be required to stop the leak, and if the flow continues unabated, that could mean a total spill of as many as 71.5 million litres.

The BP spill has already led to the cancellation of plans to expand oil drilling off the coast of California.

Gov. Arnold Schwarzenegger on Monday withdrew his support for the plan, citing the spill in the Gulf of Mexico.

This means no new drilling off the state's coast in the foreseeable future because Schwarzenegger would have to include the drilling proposal in his May revision of the state budget.

'You turn on the television and see this enormous disaster, you say to yourself, 'Why would we want to take on that kind of risk?'—Ca. Governor Arnold Schwarzenegger

Speaking at a news conference near Sacramento, Schwarzenegger said television images of the oil spill in the Gulf have changed his mind about the safety of ocean-based oil platforms.

"You turn on the television and see this enormous disaster, you say to yourself, 'Why would we want to take on that kind of risk?"' Schwarzenegger said.

Martin, however, hopes people won't "overreact."

"The concern should be, rather, how do we minimize risks? We need to look at all the technologies that are available to mitigate risks and to put in place contingency plans in case something happens … so the effects can be mitigated."

In the BP case, the flow that started after the explosion on the rig April 20 should have been stopped by a blowout preventer, a piece of equipment that squeezes the drilling pipe shut. The one on the BP rig failed, as did efforts to activate it by remote control.

Martin supports continuing to require companies to commit to drilling secondary safety wells when exploring in the Beaufort.

The National Energy Board now requires companies to commit to drilling a second relief well in the same season to relieve pressure on a main well in the event of a blowout. The fear is that without a relief well, a ruptured well would leak for more than a year.

BP cites risks of Arctic drilling

On March 22, BP asked the National Energy Board to be exempted from that requirement, saying it "is problematical for BP and other operators, and may well impede further exploration in the Beaufort Sea." The company cited improved equipment, techniques, safety management and environmental management.

As part of its argument, BP unintentionally underscored the risks of Arctic drilling, saying it is "statistically unlikely" a relief well could be completed in the same season, given the brevity of the drilling season, the depths involved and ice flows that could disrupt drilling.

Martin said the contingency planning required of oil companies will clearly increase now, as will the regulatory role of governments, especially in the Canadian Arctic.

"In the Gulf of Mexico, it's very accessible," Martin said. "In the Canadian North, accessibility is obviously an issue. The ecological damage could be absolutely enormous and could affect many other countries, because Canada is a circumpolar nation."

With files from The Associated Press