Wildrose Leader Danielle Smith came under fire Thursday at the CBC Leaders' Forum for her insistence that the science behind climate change hasn't yet been settled.

"We've been watching the debate in the scientific community and there is still a debate in the scientific community," Smith said, prompting jeers from the audience who watched the forum at CBC Edmonton.

Smith, who first made the comments in an online leaders' debate earlier this week, has come under criticism for holding this view. Progressive Conservative Leader Alison Redford — whose party is trailing Wildrose in the polls after 41 years in power — suggested Smith's position could hurt the Alberta economy.

"When I go to Washington and I talked to people in the White House and I'm trying to talk to them about why we need Keystone [pipeline], they don't want to hear that I don't believe in climate change," Redford said.

"They want to know that they have a premier and a leader from this province who's prepared to understand that this impacts our markets, this impacts our investors and if we don't take it seriously, it's going to impact our economy and our way of life."

NDP Leader Brian Mason said the majority of scientists agree that climate change is real.

"The only people that are disputing it are the phoney scientists funded by the oil industry," he said.

Smith, Redford, Mason and Liberal Leader Raj Sherman also took questions during the lively one-hour discussion about health care, seniors housing, moral issues and implementing a provincial sales tax.

It was the first and only time for the public to see all four leaders in the same place at the same time.

Sherman calls Wildrose, Tories 'false choices'

Both Mason and Sherman are trying to fight a recent suggestion by some that centrist and left-wing Albertans should vote strategically for the Tories to keep the Wildrose out.

"Do we really have to vote for two false choices?" Sherman asked. "A bunch of bullies who have been wrecking our health and education democratic systems and a bunch of bigots who want to further wreck our health and education systems?"

Most of the narrative around the campaign has centred on the battle between Redford — the leader of a party that has governed Alberta since 1971 — and Smith, the so-far unelected leader of the upstart Wildrose Party, which sits further right of the Alberta Tories on the political spectrum.

With the election looming on Monday, both women are aiming for a strong finish.

"I think one thing that the opposition leaders will all agree on is that is not a government that deserves to have another majority," Smith told the forum.

Redford tried again to distinguish her party as more progressive than the Wildrose.

"I don't know how the people that I'm asking to vote Progressive Conservative on Monday have voted before, but from my perspective we're asking people to make a positive vote for the future of this province," Redford told reporters afterwards.

Thursday's forum was broadcast on CBC-TV and Radio in Alberta as well as livestreamed on the CBC Edmonton, CBC Calgary and Alberta Votes websites.

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• Highlights Of The Alberta Election

  Here's a look back at some of the most memorable moments from the campaign.

• Wildrose Anti-Gay Blog Revealed

  A blog post saying that gays were destined to <a href="http://www.huffingtonpost.ca/2012/04/15/wildrose-anti-gay-blog-alberta_n_1427008.html" target="_hplink">burn in a "lake of fire" for eternity was brought to light on April 16.</a> Allan Hunsperger, a pastor who's running as a Wildrose candidate in Edmonton South, also referenced Lady Gaga's 'Born This Way': "You see, you can live the way you were born, and if you die the way you were born then you will suffer the rest of eternity in the lake of fire, hell, a place of eternal suffering." Wildrose leader Danielle Smith said she was aware of Hunsperger's religious views.

• Smith Booed, Mocked

  Wildrose leader Danielle Smith found herself <a href="http://www.huffingtonpost.ca/2012/04/20/danielle-smith-booed-climate-change-alberta-election-debate_n_1439858.html" target="_hplink">on the receiving end of booing and mockery at a debate on April 19 for questioning climate change .</a> "There is still a debate in the scientific community," said Smith before being drowned out by a chorus of boos and catcalls. PC leader Alison Redford said Smith leading the province would be an embarrassment.

• Candidate Makes 'White Advantage' Comment

  Wildrose candidate Ron Leech <a href="http://www.huffingtonpost.ca/2012/04/17/ron-leech-wildrose-candidate_n_1432653.html" target="_hplink">made some controversial remarks about race on a South Asian radio show.</a> "I think as a Caucasian I have an advantage. When different community leaders such as a Sikh leader or a Muslim leader speaks, they really speak to their own people in many ways. As a Caucasian, I believe that I can speak to all the community," said Leech. He apologized for his remarks on April 24, saying that his comments did not come out the way he intended.

• Redford Under Seige

  During the April 12 debate, the candidates for the Wildrose, Liberal and NDP took the opportunity to <a href="http://www.huffingtonpost.ca/2012/04/12/alberta-election-debate_n_1419850.html" target="_hplink">gang up on Progressive Conservative leader Alison Redford</a>. It was an unsurprising tactic given that the Tories have held power in Alberta for 11 consecutive majority governments, although polls reveal the Wildrose may have a fighting chance.

• Bus Cleavage

  When the Wildrose first rolled out their campaign bus, <a href="http://www.huffingtonpost.ca/2012/03/23/alberta-wildrose-campaign_n_1375998.html" target="_hplink">there was something distinctly odd about the wheel placement </a>in relation to Smith's image. Late night host Jay Leno even poked fun at the busty bus before a new, less suggestive design rolled out.

• Closing The Gap

  An April 10 poll showed that Danielle Smith's Wildrose party was <a href="http://www.huffingtonpost.ca/2012/04/11/alberta-election-2012-poll_n_1417267.html" target="_hplink">neck and neck with the Progressive Conservatives</a>. The Leger Marketing poll showed the Wildrose has the support of 36 per cent of Albertans, compared to 34 per cent for the governing Tories.

• 22 Minutes Pokes Fun At Candidates

  This Hour Has 22 Minutes gave their own take on the Alberta election by poking fun at the similarities between Alison Redford and Danielle Smith. <a href="http://www.huffingtonpost.ca/2012/04/03/alberta-election-2012-22-minutes_n_1400747.html" target="_hplink">CLICK TO WATCH</a>

• PC Staffer Gets Personal

  Progressive Conservative staffer<a href="http://www.huffingtonpost.ca/2012/03/31/pc-staffer-resigns-danielle-smith-wildrose-tweet_n_1393807.html" target="_hplink"> Amanda Wilkie "resigned" on March 31 after tweeting</a> "If @ElectDanielle likes young and growing families so much, why doesn't she have children of her own? #wrp family pack = insincere." Backlash came swiftly from the PC, the Wildrose and Twitter users alike. Alison Redford herself issues an apology, but not before Smith revealed that she didn't have children due to fertility issues.

• Awkward!

  In a moment of levity, but mostly embarrassment for Danielle Smith, the Wildrose leader's <a href="http://www.huffingtonpost.ca/2012/03/31/danielle-smith-dogs-wildrose-alberta_n_1394069.html" target="_hplink">dogs got frisky during a photo op in Calgary</a>.

• The Other Guys

  In a province where conservative values dominate politics, Brian Mason's NDP and Raj Sherman's Liberals are left to <a href="http://www.huffingtonpost.ca/2012/04/06/alberta-election-liberals-ndp-edmonton_n_1408884.html" target="_hplink">duke it out in left-leaning pockets such as Edmonton</a>.

• Controversial Issues

  On April 10, for the second time, Wildrose leader Danielle Smith was called out for her<a href="http://www.huffingtonpost.ca/2012/04/10/danielle-smith-pro-choice-gay-marriage_n_1416319.html" target="_hplink"> supposed opposing stance on abortion and gay marriage</a>. Smith however snuffed out the controversy: "When our members elected me they knew they were electing a candidate that was pro-choice and pro-gay marriage." The issues came up earlier in the election when <a href="http://www.huffingtonpost.ca/2012/04/07/alberta-election-abortion-social-issues_n_1409963.html" target="_hplink">Smith was less forthcoming</a> on the subjects.

• Tory Candidate Assaulted

  Alberta's education minister Thomas Lukaszuk claimed he was <a href="http://www.huffingtonpost.ca/2012/04/07/thomas-lukaszuk-assault_n_1410308.html" target="_hplink">assaulted while canvassing in an Edmonton neighbourhood</a>. He said he knocked on the door of a residence with a Wildrose support sign and, once recognized, was punched by the resident within. The resident, Al Michalchuk, says he merely nudged Lukaszuk when he refused to leave.