The cost of closing and cleaning up old and abandoned mines around the world likely runs into the trillions of dollars, an amount that is far beyond anything mining companies can handle on their own, according to Robert Wilson, chair of the metals giant Rio Tinto. Wilson, who made his comments during a mining industry conference being held this week in Toronto, put the estimated cost of cleanup in the U.S. alone at $35 billion. And that’s just the tip of the iceberg: “If you look at where the real problems are, in Russia, Eastern Europe, South Africa, India, China, the extent of the legacy issues is enormous,” Wilson said. Moreover, only about 5 percent of operating mines have clear plans for handling the environmental consequences of closure, according to James Kuipers of the U.S. Center for Science in Public Participation. Kuipers proposed a metals tax on consumers to help pay for cleanup, while many other conferences delegates urged governments to become more involved. But Monika Weber Fahr of the World Bank (the number one financer of mine closings) said, “It should be the polluter that should be paying.”