In 2015, for example, scientists said that an ongoing drought in Californiaâthe stateâs worst water shortage in 1,200 yearsâhad been intensified by 15 percent to 20 percent by global warming. They also said the odds of similar droughts happening in the future had roughly doubled over the past century.
Definition: Birth rate is the demographic measure of the rate at which children are born. The most well known is the crude birth rate, which is the number of births that occur each year per 1,000 people in the midyear population. It is called âcrudeâ because it does not take into account the possible effects of age structure.
Slightly fewer than 4 million babies are born in the United States each year, and the details of how, when, and where they arrive are always shifting.Total fertility rate is an estimate of the average number of births a group of women have over their lifetime. The U.S. fertility rate has been declining since 2007.The latest news is that the fertility rate in the United States is still waning â down 1 percent in 2013 from 2012.irth numbers and rates in the states. The number of births went down for 12 states, rose in 3 states, and remained about the same for the rest of the states and the District of Columbia in 2013. Birth rates ranged from 50.8 births per 1,000 women age 15 to 44 in New Hampshire to 80.9 per 1,000 in Utah.