"Ontario will join a cap-and-trade market set up by Quebec and California to reduce carbon emissions and slow the pace of climate change, provincial Premier Kathleen Wynne said on Monday.

Quebec joined California's cap-and-trade carbon market in 2014. Both are part of the Western Climate Initiative, a group of U.S. states and Canadian provinces moving to create a carbon market to reduce emissions. Ontario, Canada's most populous province, had long signaled it would also opt for cap-and-trade.

"The cost of further delay, further pollution, and further catastrophic and irreversible weather events - these are the costs that we cannot endure, the costs that we must not impose on our children and grandchildren," said Wynne, a Liberal."

Allison Martell and Mike De Souza report for Reuters April 14, 2015. [2]