Saskatchewan Premier Scott Moe is planning to speak at a rally this week where one of the organizers has questioned scientific evidence showing that human activity is causing climate change.

The Rally Against the Carbon Tax protest and truck convoy is scheduled for Thursday in Regina.

Jason LeBlanc, a farmer from southern Saskatchewan, helped organize the event after travelling to Ottawa with a convoy of pro-energy industry supporters earlier this year.

In an interview with The Canadian Press, LeBlanc called himself a "climate-change doomsday denier."

He says he believes climate changes in natural cycles, and he does not back science that says the planet is warming because of human activity and requires interventions.

Scientists from Canada have just released a comprehensive report, based on evidence, that explains how the country is warming at twice the rate of the rest of the world, largely due to human activity. The report also said that the planet would need to reduce carbon pollution to "near zero" by the second half of the century to avoid some of the harshest impacts of climate change.

The report makes it clear that the cost of doing nothing to address climate change is far greater than the cost of taking action.

Moe says he believes climate change is a global challenge but people can have different opinions about its effects. He has also been one of the leading voices arguing against the federal government's decision to impose a tax on the pollution that contributes to climate change.

NDP Opposition Leader Ryan Meili says the premier's attendance at the Thursday rally sends the wrong message.

Meili wants Moe to declare to the crowd that climate change is real.

Organizers of the convoy that went to Ottawa said that their message was meant to be inclusive for all Canadians. But some who joined their protest also expressed anti-immigrant views, leading politicians in the federal government to denounce the convoy for providing a platform for racists.

with files from The Canadian Press