Today there are Seven Billion,According to UN Population Fund

 Today there are Seven Billion of us,According to UN Population Fund,some time today we crossed the threshold for the first time. But it's only an estimate as the world's population increases by at least two babies every second.
Every 15 Seconds,a child dies from drinking unsafe water and inadequate sanitation.
In the west and developed nations ,birth rates are falling and populations are aging,In the rest of the world,poverty and large families go hand in hand to put pressure on food and water resources ,particularly in South Asia.
"The world population is outrunning its basic support systems,"says Lester Brown,President of the Earth Policy Institute in Washington.
That's why the world's forests are shrinking,its fisheries are collapsing,its grasslands are turning into deserts from overgrazing,why soil is eroding and why water tables are falling now in 18 countries that contain half the world's population. India ,China and Brazil's economic growth is putting pressure on the balance of the world's resources.
World Population in 1900  :1.6b
                                in 1927 :2b
                       Doubles by   :1970
            Population in 2011: 7b