He's been called the Jedi master of data visualisation, dubbed a statistics guru and introduced as the man in whose hands data sings. When it comes to celebrity statisticians, Hans Rosling is firmly on the A-list.

In the years since his first TED talk (Stats that reshape your worldview), which thrust him into the spotlight in 2006 with millions of online views, Rosling's now signature combination of animated data graphics and theatrical presentations has featured in dozens of video clips, a BBC4 documentary on The Joy of Stats, and numerous international conferences and UN meetings.

Instead of static bar charts and histograms, Rosling, professor of global health at Sweden's Karolinska Institute, has used a combination of toy bricks, cardboard boxes, teacups and vibrant, animated data visualisations to breathe life into statistics on health, wealth and population. With comic timing and a flair for the unusual, Rosling's style has undoubtedly helped make data cool.

When Time magazine included him in its 2012 list of the world's 100 most influential people, it said his "stunning renderings of the numbers … have moved millions of people worldwide to see themselves and our planet in new ways". However, Rosling, 64, is less convinced about his impact on how people view the world.

"It's that I became so famous with so little impact on knowledge," he says, when asked what's surprised him most about the reaction he's received. "Fame is easy to acquire, impact is much more difficult. When we asked the Swedish population how many children are born per woman in Bangladesh, they still think it's 4-5. I have no impact on knowledge. I have only had impact on fame, and doing funny things, and so on."

He's similarly nonplussed about being a data guru. "I don't like it. My interest is not data, it's the world. And part of world development you can see in numbers. Others, like human rights, empowerment of women, it's very difficult to measure in numbers."

Rosling is strikingly upfront about the limitations of data. Sometimes, the problem is that different countries measure things – like unemployment – in different ways, he says. In other cases, there are real uncertainties in the data that must be assessed: child mortality statistics are quite precise, whereas maternal mortality figures are not; global poverty measurements are infrequent and uncertain.

"That unit [at the World Bank] which assists countries, trains the staff, and helps them to compile [poverty] data, how many persons are working there? Four half-time. For the world. It's a joke. They're very competent, they're very good. But it's not serious … The uncertainty of 1.3 billion [people living in poverty] is plus or minus half a billion. And we will not know whether the MDGs [millennium development goals] have been achieved until 2019, the later part. We only get poverty measurements every fifth year."

These issues are well known, he says, but still underappreciated and infrequently discussed. "It's like the emperor's new clothes, and I'm the little child saying 'He's nude! He's nude!'"

Still – when handled with care – global statistics can help challenge common myths and misconceptions about the world, Rosling hopes. Chief among the myths still to be debunked, he says, is the idea that the world is split in two – with a developed world on one side and a developing world on the other. "We don't have two types of countries any longer, we have four or five types … [and] the idea that the western world will be ahead of the rest for ever is wrong."

Anxiety about population growth is another of Rosling's targets. "If you save the lives of poor children you destroy the planet. There are so many who think that death keeps control of population growth. That's just wrong!" Child mortality has plummeted over the past half-century, so it's no longer death that determines population growth, he insists, but fertility rate – and this too has decreased in so many countries. "The average number of children in the world is 2.4. The number of children below eight years of age in India has stopped growing. The number of children in the total world has stopped growing. Most of the fertility transition is done."

"I can show you! Let me show you the world," he enthuses, interrupting our interview only briefly to pull from his pockets a series of props. Laying out toy bricks and a handful of counters on the table, he shows in 3-D how the dynamics of global population, child mortality and carbon emissions have changed over the past 50 years – and how the world might look by the end of the century.

"[We now have] 7 billion people, [with] 7 million children dying. Six [million] of these die in the poorest 2 billion, 1 die here in the middle and here almost no one. Can you see?" he asks, waving his hands over his display. "There is no developing world with high child mortality! It is 2 billion people that still have three or more children per woman, where still girls cannot go to school, or very few, and where you have almost all the child mortality and almost all the maternal mortality."

If Rosling comes across as advocating for a shift in focus towards the poorest countries, he's adamant he's not. "I don't debate. There are too many debates. Too much Word, not enough Excel.

"If people want to help with something, it's good to know where the problem is … [for example] the problem of lack of schooling for girls is not a global problem. It is not a developing world problem, it's a problem in the poorest 2 billion. But there it's an extremely severe problem … Men in Afghanistan have half the schooling of women in the world. But young women in Afghanistan have one-seventh of the men in Afghanistan. This is the world I would like to explain."

Disappointed with his perceived lack of impact on public understanding of global progress, the self-styled "edutainer" is now turning his attention towards teachers. Over the next few years, his Gapminder foundation will push through a school project to provide materials on the basic macro-trends on population, economy, living conditions and energy, to help teachers in high school and college to better communicate the realities of the world.

"Fame is a dangerous thing. It's what the post-industrial society wants. They want fame and many followers on Twitter. But to really make the world understandable, that challenge is remaining."