Hans Rosling: How much do you know about the world?

The world may have many problems, from climate change to armed conflict, natural disasters, poverty and the oppression of women and minorities - but where does population growth fit into this catalogue of woes?

With the population of the world at seven billion and rising, many fear a shortage of resources as well as a shortage of space. Swedish professor Hans Rosling, however, says it's time for a reality check.

When pollsters got 1,000 British people to take Rosling's "ignorance survey" in May this year, the results suggested they knew "less about the world than chimpanzees", he says.

Take a version of the test in this quiz, compare your results with the British respondents', then read Hans Rosling's five reasons the world is in better shape than we think.

1.) Multiple Choice Question In 1950 there were fewer than one billion children (aged 0-14) in the world. By 2000 there were almost two billion. How many do UN experts think there will be in 2100? Two billion

Three billion

Nearly four billion

2.) Multiple Choice Question Which map best shows how the world's seven billion people are spread between the Americas, Europe, Africa and Asia? Each figure represents one billion. (A)

(B)

(C)

3.) Multiple Choice Question What is the average life expectancy at birth in the world today? 50 years

60 years

70 years

4.) Multiple Choice Question What is the literacy rate for adults in the world as a whole today? 80%

60%

40%

5.) Multiple Choice Question Which curve shows the present income distribution of the world as a whole, measured in dollars earned per day? (A)

(B)

(C)

6.) Multiple Choice Question In the world as a whole, men now aged 25-34 years spent a total of eight years at school. How long did women in the same age group spend at school? Three years

Five years

Seven years

7.) Multiple Choice Question In the last 20 years, how did the proportion of the world population living in extreme poverty change? Almost halved

Remained much the same

Almost doubled

8.) Missing Word Question About * of world energy comes from solar and wind power 1%

5%

10%

9.) Multiple Choice Question In 1965 women had five babies, on average worldwide. How many do they have on average today? (A) 4.5

(B) 3.5

(C) 2.5

Answers It's two billion, much the same as in 2000. We have, in Hans Rosling's words, entered the age of Peak Child. When a similar question was put to just over 1,000 British respondents in May this year, nearly half guessed four billion, and most of the rest guessed three billion. Only 8% selected two billion or less. It's map B. The Americas, Africa and Europe each have a population of about one billion, while Asia's population is about four billion - in Hans Rosling's phrase, the Pin code of the world is 1114. Only 35% of British respondents (who were shown four maps rather than three) picked the right one. It's 70 years. There has been a 10-year rise in life expectancy over the past five decades, thanks to great advances in healthcare. A majority of British respondents thought the correct answer was 60 years or less. Some 80% of adults in the world today can read and write. Only 8% of British respondents got this right - and half thought the right answer was 40% or less. Respondents with university education were even more likely than others to get it wrong. It's B. In the past our world was fairly clearly divided into two distinct groups of rich and poor, corresponding to what we called "developed" and "developing" countries (similar to curve C). But today the picture is different. When it comes to income, we have a continuously distributed world where most people live in the middle. It's seven years. Huge progress has been made in improving girls' access to education. It's tragic when girls are prevented from going to school by cultural taboos, but the numbers affected are shrinking. When British respondents were asked a similar question, some 79% picked a figure lower than seven years. Extreme poverty has almost halved in the last 20 years. It's one of the great success stories of our age. One billion people still live in extreme poverty, but six billion do not (meaning that they earn more than $1.25 per day). This news had not sunk in for many British respondents - more than half thought extreme poverty had increased in the last two decades. About 1% (or between 1% and 2%) of the world's energy today comes from solar and wind power. Two-thirds of British respondents severely overestimated the role of renewable sources of energy. The fact is that about 80% of the world's energy still comes from fossil fuels, and most of the remainder comes from nuclear and hydroelectric power. It's 2.5 babies. One of the great changes in the world in the last 50 years is the fall in the average fertility rate from five to 2.5 - and it's still falling. The British survey did not include this question, but it did ask how many babies women in Bangladesh had on average. The answer is also 2.5 - but a majority of respondents thought it was 4.5 or more. Your Score 0 - 2 : To err is human 3 - 5 : Average, or "chimp" level 6 - 9 : Great ape

"If for each question I wrote each of the possible alternatives on bananas, and asked chimpanzees in the zoo to pick the right answers, and by picking the right bananas, they'd just pick bananas at random. But the Brits did even worse," says Rosling.

To be fair, so did the Swedes, the only other nation to have been polled so far. In a speech to TED downloaded almost six million times, he points out that he also put the questions to some fellow professors, and they were on a par with chimpanzees, too.

The fact that humans do worse than chimps shows the problem is not a lack of knowledge, but the result of having preconceived ideas, Rosling says - ideas that are years, or sometimes decades out of date.

"What is particularly striking is that those with a university education did not do better - if anything worse - than everyone else," he says.

Rosling infers from this that most people are ignorant about the profound ways the world is changing, "often for the better".

Some "ignorance survey" questions - and the British answers:

Question: In the year 2000 the total number of children (age 0-14) in the world reached two billion. How many do UN experts estimate there will be by the year 2100?

Options All respondents University graduates Source: United Nations a. 4 billion 48% 45% b. 3 billion 44% 48% c. 2 billion Correct answer 6% 6% d. 1 billion 2% 1%

Question: What percentage of adults in the world today are literate - ie can read and write?

Options All respondents University graduates Source: World Bank a. 20% of adults 12% 15% b. 40% of adults 38% 43% c. 60% of adults 43% 39% d. 80% of adults Correct answer 8% 4%

Question: What is the life expectancy in the world as a whole today?

Options All respondents University graduates Source: World Health Organization a. 40 years 5% 7% b. 50 years 18% 23% c. 60 years 33% 43% d. 70 years Correct answer 30% 20% e. 80 years 14% 8%

Question: In the last 30 years the proportion of the world population living in extreme poverty has…

Options All respondents University graduates Source: United Nations a. increased 58% 55% b. remained more or less the same 33% 33% c. decreased Correct answer 10% 12%

Question: What percentage of total world energy generated comes from solar and wind power? Is it approximately...

Options All respondents University graduates Source: International Energy Agency a. 2% of energy Correct (1-2%) 30% 37% b. 5% of energy 29% 32% c. 10% of energy 22% 18% d. 20% energy 16% 12% e. 40% of energy 3% 1%

Don't Panic - The Truth About Population will be broadcast on BBC Two on Thursday 7 November at 21:00 GMT (23:20 GMT in Scotland. Or watch it later on the BBC iPlayer.

Hans Rosling answered readers' questions on @BBCNewsMagazine's Twitter account.

Here is a selection of the questions and answers.

Q: Should there be a global population cap? The globe can only support a finite number of people.

A: Of course not. You would have to kill, sterilise by force or at least stop public child welfare.

Q: How will the population be divided based on age, considering the increasing age of population overall

A: It is not so much increased age, it is a higher proportion old because fewer and fewer are born.

Q: What about the environment? We already need 1.5 earths to supply our needs, with 7 billion people in the world.

A: We must obviously be much more clever in using resources, regulate with tax and promote innovations

Q: Do you think in 80 years traditional developed nations will pay people to immigrate as they won't have enough labour?

A: Yes, Vietnamese migrants are yearly picking the wild lingonberries in the Swedish forests.

Q: What is the biggest problem facing the human race today that is not being addressed?

A: I don't know, it´s probably a problem we have not yet understood how big it will soon be.

Q: How much does media coverage of female education and poverty in Indian sub-continent etc. influence our beliefs?

A: It seems the public in Europe has not yet learnt that most girls in India today go to school.

Q: Should borders be abolished to encourage the free movement of individuals?

A: In my dreams it happens, when I wake up I just hope for an even better and stronger UN.

Q: Do you think the gap between rich & poor nations will narrow as it has between rich & poor in western Europe?

A: The gap is gone. Most nations are in the middle, some richer and some poorer.

Q: Of all possible threats from exhaustion of resources which will finally cause us to see what we've already lost?

A: May be the exhaustion of resources that leads to a war that is worse than the exhaustion.

Q: At what date and at what number do you envisage that the human population will stabilise?

A: I just follow what the UN experts estimate, second part of this century, at 9-12bn.

Q: Why were your test results surprising amongst university students? Is it important for everyone to go to uni?

A: I (naively) thought university training would make you better in following what happens in the world.

Q: Given trouble our consumption is causing, surely we should panic at the prospect of a 50% increase to 11bn people?

A: Britain didn't win WWII by panicking. Let´s be bold, determined and stick to the best of values.

Q: How will the Japanese economy cope with its expected substantial decline in population over the coming decades?

A: In strange ways. In Japan sale of geriatric diapers is now bigger than baby diapers.

Q: Will the world population be able to have the quality of life that the middle class in the developed world enjoys?

A: Hopefully yes, otherwise we will get tragic conflicts in the world.

Q: We get energy from food that comes largely from the sun. Is that part of the 2% that comes from solar and wind?

A: Food and feed is not conventional part of the concept "energy production".

Q: Why is the world in better shape? Are we misinformed?

A: Most people are not updated. 50 years ago 1 in 5 children died before age 5, now only 1 in 20!

Q: Do you think the reason university graduates performed less well is due to becoming cynical while studying?

A: Truly, I do not know, but Gapminder will investigate why.

Q: What's the likely impact on mortality & population as people migrate to areas with better food & water supplies?

A: The most important migration is to cities. In poorest countries this improves health.

Q: At what point will population pressure next spark a major war?

A: It may be an underlying factor behind conflicts about land in the poorest countries.