Canadian Prime Minister Justin Trudeau, right, greets Secretary-General of the United Nations Antonio Guterres as they hold a bilateral meeting in Montreal

Video. COP15 biodiversity summit opens in Montreal

Amid warnings that biodiversity is in freefall, environmental leaders have gathered in Montreal to hammer out measures aimed at shoring up the world's land and marine ecosystems and coming up with tens of billions of dollars to fund conservation efforts.

Amid warnings that biodiversity is in freefall, environmental leaders have gathered in Montreal to hammer out measures aimed at shoring up the world's land and marine ecosystems and coming up with tens of billions of dollars to fund conservation efforts.

Delegates from about 190 countries assembled for the two-week summit to finalise a framework for protecting 30% of global land and marine areas by 2030. Currently, 17% of terrestrial and 10% of marine areas are protected.

The proposed framework also calls for reducing the rate of invasive species introduction and establishment by 50%, cutting pesticide use in half, and eliminating the discharge of plastic waste.

The goals - more ambitious than earlier ones that have mostly gone unmet - are expected to be at the heart of the meeting debate. But not far behind will be the issue of finance, with developing countries likely to push for significant monetary commitments before signing onto any deal.