Jason Tanz
01 22, 2015

Gates visits an agricultural processing center in Ethiopia in March 2012.

Gates visits an agricultural processing center in Ethiopia in March 2012.  Gates           Foundation

BILL GATES PROVES that one person can make a difference—if he happens to be the richest person in the world. Since forming the Bill & Melinda Gates Foundation—and especially since leaving Microsoft in 2008 to dedicate himself full-time to the foundation’s work—Gates and his wife Melinda have emerged as two of history’s most powerful philanthropists, funding efforts from polio eradication to sewage-treatment plants, and setting the agenda for aid organizations around the world. They have convinced 127 fellow billionaires to sign their giving pledge, an oath to donate the majority of their wealth to philanthropic organizations. Today, the Gates Foundation has an endowment of $42 billion, almost four times the size of the Ford Foundation, and it distributes between $3 and $4 billion every year. As WIRED Science writer Maryn McKenna put it a few years ago, “Where Gates goes, governments and the media follow.”

So when Gates releases his annual letter each January, summarizing the foundation’s progress and laying out its priorities for the coming year, the world pays attention. Last year’s edition, a feisty debunking of “myths” about poverty, went viralThis year’s letter, co-written by both Bill and Melinda Gates and released today, is even more ambitious than usual. Titled “Our Big Bet for the Future,” it lays out a series of goals for the next decade and a half—cutting childhood deaths by half, eradicating polio and three other diseases, and making Africa capable of feeding itself, among others. Altogether, the letter predicts, “the lives of people in poor countries will improve faster in the next 15 years than at any other time in history.”

The letter is modeled on the UN’s Millennium Development Goals, a set of 15-year targets that expire this year and that Gates refers to as “one of the most important documents the UN ever did.” Representatives from every country in the world signed the goals in 2000, pledging among other things to reduce extreme poverty by 50 percent, slash child mortality by two thirds, and cut the maternal mortality rate by three quarters. Although not every target was reached—a full report card can be foundhere—the document is generally credited with focusing global aid efforts and providing a yardstick against which they can be measured. The UN is set to introduce a new set of development goals this September, and some observers worry that they will be a disappointment rather than an inspiration. Writing for the Guardian, Kevin Watkins frets that the discussions to date have been “hampered by a paralyzing lack of ambition, weak leadership, and the absence of a credible agenda to galvanise public engagement.”

That certainly does not describe this year’s Gates letter, the most rabble-rousing edition to date. Toward the end, the Gateses announce Global Citizens, a new program to educate and inspire action among the general public. “We want to give global citizens a way to lend their voice, urging governments, companies, and nonprofits to make these issues a priority,” the letter explains. In particular, the Foundation will ask its Global Citizens to push for a meaningful reboot of the UN’s Millennium Goals, and to hold their governments accountable for meeting those targets. It’s a surprisingly populist approach for the Foundation, which has tended to turn to billionaires for the bulk of its support.

In a wide-ranging phone conversation, WIRED spoke with Gates about this year’s letter, global inequality, and President Obama’s tax proposals. The interview has been edited for length and clarity.

The UN is working on its update to the Millennium Development Goals. How do you think it’s going?

We’re definitely on track. It will be a much longer document, and a broader set of goals than the MDGs were.