The environment is emerging as 鈥渙ne of the defining battle grounds鈥� for the upcoming federal election, according to Nanos Research analyst Nik Nanos.

鈥淔or the first time in 15 years, the last four weeks have had the environment as the top national issue of concern,鈥� Nanos told 麻豆传媒. 鈥淢ore important than jobs, more important than health care, more important than immigration.鈥�

Concerns about the environment have been rising in the public consciousness ever since a landmark UN report was put out last fall, which laid out a grim picture of the future if world leaders across the globe can鈥檛 slow down human-caused warming of the planet.

In the political sphere, the issue of how best to tackle climate change has been a source of contention, with federal Conservative leader Andrew Scheer and several premiers opposing the Liberal government鈥檚 federal carbon tax.

An Ontario court ruled Friday that the federal government鈥檚 carbon tax is important to the fight against climate change and is constitutionally sound. This ruling means the 鈥渢he battle lines have been drawn,鈥� Nanos said.

鈥淭his recent court decision is a direct body blow to the government of Ontario, the government of Alberta, the government of Saskatchewan, because what it says is that the feds can intervene and take leadership on environmental issues and on the carbon tax,鈥� Nanos said. 鈥淚t鈥檚 a green light and positive news for the Liberals, not good news for those provinces opposing the carbon tax.鈥�

The federal carbon tax went into effect in April in provinces that did not have a climate change plan that met federal approval: Saskatchewan, Manitoba, Ontario and New Brunswick. It will be due to the new provincial Conservative government鈥檚 repeal in May of the former NDP鈥檚 carbon tax in Alberta.

Nanos said that betting on a tax as a 鈥渨inning issue鈥� in an election is a 鈥渟lippery slope.鈥�

鈥淏ecause people love the environment, they want to protect the environment, but once you reach into their pocketbooks and into their wallets, people start to get a little nervous,鈥� he said. 鈥淪o the Liberals have to be careful.鈥�

The NDP and Green Party also support a carbon tax. The Conservatives released their long-awaited environment plan this month, which does not include a carbon tax or any estimates on how much their many ideas could reduce greenhouse gas emissions.

鈥淔or those against, they鈥檙e going to characterize [the carbon tax] as a cash grab,鈥� Nanos said.

鈥淪o it鈥檚 going to be a classic fight between the heart and the wallet in the next federal election.鈥�

Methodology: For this weekly issue tracking, Nanos conducted an RDD dual frame (land-and cell-lines) hybrid telephone and online random survey of 1,000 Canadians, 18 years of age or older, for the week ending June 21, 2019. Participants were randomly recruited by telephone using live agents and administered a survey online. The sample included both land-and cell-lines across Canada.

The margin of error for a random survey of 1,000 Canadians is ±3.1 percentage points, 19 times out of 20.