Just like legitimate industries from hotels to taxis, the criminal underworld is undergoing its own digital revolution. One sign of cybercrime’s increasing sophistication—and one reason why it’s booming—is that criminals don’t even have to write their own malicious software. They can buy a “plug-and-play” kit from those who do.

And environmentalists are cautiously optimistic that China’s carbon-dioxide emissions may be falling, largely thanks to the country’s extraordinarily rapid investment in solar and wind power. Good news. The question now is: if emissions have peaked, how quickly can they fall?

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