Sao Paulo officials knew the city was running out of water, and did nothing, says Jeffry Sachs.

One year ago, I was in Brazil to launch the Brazilian chapter of the United Nations Sustainable Development Solutions Network (SDSN), an initiative of UN Secretary-General Ban Ki-moon. The main message I heard that day was that São Paulo was suffering from a mega-drought, but that state and local politicians were keeping it quiet. This is a reality around the world: too many political leaders are ignoring a growing environmental crisis, imperiling their own countries and others.

In the case of Brazil, state and local officials had other things on their mind in 2014: hosting the World Cup soccer tournament in June and July and winning elections later in the year. So they relied on a time-tested political tactic: hide the bad news behind a “feel-good” message.