Prime Minister Justin Trudeau will join dozens of other world leaders at the United Nations on Friday for the formal signing of the Paris climate agreement.

The agreement has been hailed as “historic” for its ambitious targets and the involvement of nearly 200 countries. It was adopted at the COP21 summit in December and will be signed at the UN on Earth Day. It will then be ratified individually by each government. 

In a statement this week, the Prime Minister’s Office said that Canada has “resolved to be an international leader in the low carbon global economy over the coming decades.”

The key elements of the Paris agreement are:

Keep global warming below 2 degrees Celsius. Since global temperatures have increased by about 1C since pre-industrial times, the agreement aims to keep any further warming “well below” 2C by working to reduce greenhouse gas emissions as soon as possible.

Individual emissions targets. The signatories have agreed to set national targets for reducing greenhouse gas emissions every five years. The Paris agreement also asks nations to review their targets in the next four years.   

Reporting emissions. The agreement includes requirements that countries be transparent about their emissions, but there will be no penalties for missing targets.

Helping poorer countries. The agreement says wealthy countries should offer financial support to poor nations to help them reduce their emissions. Other countries are also encouraged to contribute on a voluntary basis, but the agreement did not set any actual dollar amounts. 

Although Trudeau has touted tackling climate change as one of his government’s biggest priorities, he and Environment Minister Catherine McKenna have not said exactly when Canadian greenhouse gas emissions will start to decline.

The latest numbers show that Canadian carbon emissions increased steadily between 2009 and 2014. In 2014, they reached 732 megatonnes of carbon dioxide equivalent – 20 per cent higher than emissions recorded in 1990.

After McKenna appeared before a House of Commons environment committee to discuss the issuethis week, she told reporters that market conditions in the oil patch will determine emissions output in 2016.

“Emissions are going up and they need to go down,” McKenna acknowledged, without offering assurances that will change soon.

 "A lot of that will depend actually this year on the market," she said.

The Liberals have also been criticized for relying on emissions targets set by the previous Conservative government, which aim to reduce emissions 30 per cent below 2005 levels (749 megatonnes) by 2030.

The feds have been consulting with provincial governments on the issue and working groups are expected to report back to Ottawa next fall.

With files from The Canadian Press and The Associated Press