Sarcasm is difficult for artificial intelligence to understand, but computer-science graduate students Mikhail Khodak, Nikunj Saunshi, and Kiran Vodrahalli have simplified it through a SARCASM DATABASE of some 1.4 million snarky comments — 10 times larger than the next largest database of its type. The researchers, who published their methods in the journal arXiv in April, pulled the phrases from Reddit, where the symbol “/s” is used to mark sarcasm. 

To combat RAMPANT SMOG, China is considering converting some coal-fired plants to synthetic natural gas. A study led by environmental-engineering professor Denise Mauzerall found that while substituting gas in all residential areas would dramatically reduce air pollution — averting some 30,000 deaths annually — the production of synthetic natural gas from coal could release some 150 million extra tons of carbon dioxide and other greenhouse gases per year. The study, published in the Proceedings of the National Academy of Sciences in March, illustrates the complicated public-health consequences of climate change.