Lawyers of governments, led by Prime Minister Justin Trudeau and Prime Minister Doug Ford, are not the only ones to question this week about a federal carbon tax bill in the courtroom in Toronto.
On the third day of the Ontario legal challenge, the five-member court will deal with environmental, indigenous and tax groups, as Ford's government continues its legal fight against tax.
CBC Toronto has been in the process of running court proceedings, as lawyers presented presentations at the Ontario Court of Appeal on Wednesday.
The essence of the constitutional challenge is whether the federal government has the right to impose carbon tax on the landscape. Supporters of Ontario's position say that fixing pollution prices is unfair to taxpayers, while those who agree with the federal government say pollution is a national concern.
Canadian federation of taxpayers
The Canadian Federation of Taxable Persons (CTF) supports the region in its fight against the implementation of the federal carbon tax, as it supports lower taxes.
"There is a problem with the tax and the way it is implemented," said CTF Director Aaron Wudrick.
"Governments are very creative in dealing with how they want to create things [taxes] more pleasant. "
Ford spoke of pan-Canadian politics at the time of queries at Queen's Park on Wednesday, when he said that the great victory of Albert Jason Kenney won yesterday the fight against Ontario's carbon tax.
"We are building an anti-Corruption Alliance, as this country has never seen before," Ford said, stressing that five prime ministers across the country will oppose the Ottawa framework soon.
The CTF has long been engaged in tax.
Athabasca Chipewyan First people
The first nationality of Athabasca Chipewiana in Alberta says climate change will have a negative impact on her lifestyle.
A lawyer representing the first country says that carbon tax is the best solution that Canadians must solve.
He said temperatures would rise by seven degrees by the end of the century.
"You destroy ecology, destroy the way of life of Aboriginal people and destroy them as a culture," said a lawyer from Ottawa Amir Attaran.
"For them, climate change is an existential threat."
Several indigenous groups are also an intervening party, including the Assembly of the First Nations.
Canadian Public Health Association
For the Canadian Public Health Association, climate change is a worrying public health, which can only be dealt with by the federal government by fixing the price of pollution.
"Greenhouse gases do not respect regional or national borders," said Ian Culbert, executive director.
He said that there can often be a "patchy" blanket to protect the health of Canadians.
"This is one of the most serious threats to public health in the 21st century."
Program Director of Environmental Defense Keith Brooks says that the government's plan for the environment is "not tight enough" in the fight against climate change.
Not ambitious enough.– Keith Brooks, Environmental Defense
As the court heard on Thursday, Ontario has already reduced its greenhouse gas emissions by 22 percent from the 2005 level, largely due to the decommissioning of all coal-fired power generation. This happened with the previous government.
The PC plan includes a $ 400 million fund in four years to help companies develop clean technologies.
"There is no mathematics for the plan," Brooks said. "Not ambitious enough."
Brooks says carbon tax will have a very small impact on the affordability of life, while underestimated climate change will lead to floods in homes and cause forest fires.
"This has a far greater impact on the quality of life of people than four cents per liter of gasoline."