In 2005, Bjorn Lomborg bounced onto the TED stage in Monterey to challenge the audience to think about “the biggest problems in the world.” Author of the book The Skeptical Environmentalist and the director of the Copenhagen Consensus Centre, Lomborg promptly advised the somewhat startled audience to forget about global warming. If we really want to make an impact on the serious issues of our time, he said, we have to look beyond the dramatic images and histrionic headlines that fill our newspapers, and instead calmly and rationally focus on tackling issues we might actually solve once and for all.

“It’s when economics gets evil,” he said cheerfully.

Back then, Lomborg was presenting the results of the first Copenhagen Consensus, for which he had convened a group of 30 of the world’s top economists to prioritize global problems according to how quickly and efficiently they might be solved. Their top recommendations: focus on curing HIV/AIDS, solving hunger, establishing free trade, and abolishing malaria.

“We want ordinary people who’ll spend $100 or $10 a year on doing good in the world to ask where they might do the most good.”

Since then, he and his team have run the same survey twice more, in 2008 and in 2012. And most recently, Lomborg published a book of some of his thinking, the pithily titled How to Spend $75 Billion to Make the World a Better Place. But, as he told me in a recent telephone call, our general pattern of tackling big issues remains the same. “We still have a tendency to spend money on those groups with the best PR, or the groups with the cutest animals or the scariest pictures,” he said. “And that’s not necessarily the best way to spend our money.”

Nine years after that first survey, the results haven’t changed much, though now, solving malnutrition has risen to the top of the list. “If you spend $3 billion over the next four years, you could save 100 million kids from malnutrition,” says Lomborg. “Of course, hunger is a bad thing. But it turns out that solving this has much bigger implications than just curing the terrible indignity of kids suffering pangs of hunger. Feed them properly and they’ll develop better both physically and mentally, they’ll stay longer in school, so they’ll learn more.” Lomborg cites the results of a program run in Guatemala in the 1960s, in which children from villages who were fed well were monitored against those from a different village who weren’t. The difference decades later is stark. “Better marriages, fewer kids, better educated, better jobs, but most importantly from an economist’s point of view, the better fed children now make three times more money,” he says. “If we can make that happen for 100 million kids over four years, that could very likely lead to a virtuous circle.”

Lomborg is just as lively and hopeful today as he was back in 2005. And he says he’s neither frustrated nor disappointed by the lack of change in his survey’s findings. “We were a little afraid that things might just stay the same,” he acknowledges. “And there are some obvious repeats, but there are also a lot of new findings. For instance, AIDS went down. That was the top priority in 2004, but we managed to get hold of the AIDS epidemic and see a decline in new infections. That does not mean it’s over, but we’ve managed to cut off some scary scenarios.”

And, he says, people are beginning to understand his point of view more clearly. No longer do they think he is the antichrist for suggesting that global warming shouldn’t be a focus, at least with current methodologies for tackling it. “More people realize the current Kyoto-style approach hasn’t worked for 20 years,” he says. “At some point you have to say ‘let’s not do this again.'”

So why the $75 billion number for his new book? It’s an arbitrary figure, he confesses, but in the grand scheme of things, it’s also a reasonable target for spending on these big, seemingly intractable issues. And really, he wants all of us to think about where our charity dollars can make the most impact. “We want ordinary people who’ll spend $100 or $10 a year on doing good in the world to ask where they might do the most good,” he says. “Sure, Bill Gates could spend $75 billion himself, but we can all think about making the world a better place.”