Wednesday links: China child abduction, Arctic methane, econoblogs and more

• The release of methane from melting Arctic permafrost could cost the world $60 trillion, says the journal Nature. The entire global economy was worth $70 trillion in 2012.
• Economists are taught too little history.
• The ten most expensive cities in the world. You'll never guess no.1.
• The Atlantic's Conor Friedersdorf is astounded by Michael Hayden's interview with the Financial Review.
• Do economics blog change minds? Yes.
• Robot planes are the future of war at sea, but Mav and Goose are not out of a job just yet.
• Charlie Custer writes about child abduction in China. He's also made a documentary about it:

[vimeo:47417676]