Seven surprising facts about the Earth's 7 billion

The world has reached a major milestone: According to the United Nations the Earth's population has crossed the seven billion mark.

Unfortunately, seven billion isn't necessarily cause for celebration - more people could create more potential problems.

On "The Early Show," CBS News correspondent Mo Rocca detailed a few things you may not know about our new population. Keep clicking to find out surprising facts about the world's growing number of inhabitants.

World population: Seven billion and counting
Special section: Eye on Parenting
"7 billionth" babies celebrated worldwide

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1. The world has never had more people. We're adding 80 million annually - that's the population of Germany every year. But our world growth rate is actually on the decline.

Joel Cohen, population professor at Rockefeller University and Columbia University, explained, "It's gone from about five children per a woman -- a worldwide average in 1950 -- to about 2.5 children per woman now."

Seen here is newborn Danica Camacho, the Philippines' symbolic seven billionth baby. Camacho was born in Fabella Maternity hospital in Manila on Oct. 31, 2011.

World population: Seven billion and counting
Special section: Eye on Parenting
"7 billionth" babies celebrated worldwide

Credit: AP

2. In some countries, a low birth rate may actually be a problem. In Italy, for instance, women have on average 1.2 children -- well below replacement level, CBS News correspondent Mo Rocca reported.

Cohen said, "Some people think it is a big problem because it means that the population is aging rapidly. The aging population means there will be fewer young people to support the elderly in their old age, if the elderly retire, for example."

So unless Italians seriously reconsider their immigration policies or raise their retirement age, Mo Rocca said, "Well, they better get busy."

World population: Seven billion and counting
Special section: Eye on Parenting
"7 billionth" babies celebrated worldwide

Credit: CBS

3. Seven billion isn't such a space issue, Mo Rocca pointed out. If everyone in the world stood shoulder to shoulder, we could all fit within the city limits of Los Angeles.

World population: Seven billion and counting
Special section: Eye on Parenting
"7 billionth" babies celebrated worldwide

Credit: iStockphoto

4. No one on Earth has to go hungry, according to Cohen, population professor at Rockefeller University and Columbia University. When asked if we have enough food to feed everyone, he said, "Yes, last year the world grew about 2.3 billion metric tons of cereal grains and that amount of food could provide enough calories to feed between nine billion people and eleven billion people."

However, the problem is only 46 percent of that amount goes into human mouths -- most of the rest goes to the animals many of us like eating. That's partly why one billion people go hungry every day, Mo Rocca noted.

Cohen said if the number of vegans were to increase, the expanding world population would "certainly" be more sustainable.

World population: Seven billion and counting
Special section: Eye on Parenting
"7 billionth" babies celebrated worldwide

Credit: iStockphoto

5. The strain on the world's resources, Mo Rocca noted, is not so much about the number of people, as it is the number of households. Six people sharing one refrigerator consume a whole lot less energy than six people with six separate refrigerators.

World population: Seven billion and counting
Special section: Eye on Parenting
"7 billionth" babies celebrated worldwide

Credit: CBS/iStockphoto

6. Education is the biggest factor in controlling population.

Cohen, population professor at Rockefeller University and Columbia University, said, "When young people are in school, they generally get married at a later age. So that slows the onset of marriage and having children. When they've been educated, they generally have fewer children in their whole lifetime."

World population: Seven billion and counting
Special section: Eye on Parenting
"7 billionth" babies celebrated worldwide

Credit: iStockphoto

7. In just three minutes, 900 people are born, 360 people die, and the world gains 540 people.

World population: Seven billion and counting
Special section: Eye on Parenting
"7 billionth" babies celebrated worldwide

Credit: iStockphoto