The meeting was attended by climate crusader Al Gore and former New York mayor Michael Bloomberg.
The idea of a setting a price for the cost of carbon is to encourage polluters to reduce the amount of greenhouse gases they emit by making them pay the bill and focus on the need to develop and invest in green technology.
Royal said that while a single carbon pricing would not be achievable, there should be a “price window” between an agreed bottom figure and a higher price.
In Europe, the current price of 8 euros per tonne was too low, she said, adding that 15 euros should be the minimum.
“The challenge is to drive up the price per tonne of CO2, which is currently too low at 8 euros per tonne,” she said.
France has set a carbon price of 22 euros per ton, which will increase gradually to 100 euros in 2030.
Royal said the drop in oil prices could provide a boost to companies who may choose to direct saving from the lower prices toward their transition to cleaner technologies.
“With lower oil prices, we are at the perfect moment to introduce a carbon price. It will be more readily accepted,” she argued.
Some 60 countries and regions are paying for carbon emissions through taxes or carbon markets, with China preparing to create a domestic carbon market next year.