A lawyer for the Canadian government says a lawsuit filed by 15 youth across the country should be dismissed because their claims about the harms of climate change are too broad.

Joseph Cheng says greenhouse gas emissions are cumulative and a worldwide problem that affects all countries so Canada cannot act alone to resolve the impact of climate change.

The lawsuit filed in October 2019 by youth who are now between 11 and 20 asks the court to compel Canada to develop a climate recovery plan based on the best available science.

Cheng says extreme weather events caused by climate change, such as floods and wildfires, are one of the defining issues of our time that affects everyone and a trial to determine the federal government's response is not warranted.

However, he agreed with the plaintiffs that Canada is not on target to meet its own commitment to reduce emissions this year after signing and ratifying three international accords to combat climate change.

The plaintiffs say in their statement of claim that youth are disproportionately affected by air pollution and other consequences of greenhouse gas emissions because their vital organs, including the lungs, are not fully developed.