Perhaps you should first investigate the question: "Has there really?" What evidence is there that there has, indeed, been a rise in multiple births? Perhaps there has been, perhaps there hasn't, but it would be better to confirm this point before going any further, searching for mysterious reasons for something that - perhaps - didn't even happen.
In the last 400 years (since 1610) there have been 97 leap years. The most recent was 2008.
For all recorded history somebody has been born and somebody has died everyday. It seems possible that millions of years ago when the human population was very very small that a day occurred on which there were no births or deaths.
The Bible reveals that only four people were sanctified by God before their births for a special purpose, including Jeremiah, John the Baptist, Jesus Christ and the apostle Paul.
It varies depending on demand. In recent years production has been between 7 and 13 billion pieces per year. Production figures for years up to 2003 are available at the link below
17.7 and 20.9
The number of multiple births per year can vary depending on the population and region. In the United States, for example, about 3% of all births are multiples, which includes twins, triplets, and higher order multiples. This percentage has been relatively stable over the years.
The incidence of triplets has decreasing, not increasing, for more than ten years.
Chance of having 'natural' triplets: 1 in 8,100 (only about 30% of triplets are 'natural') There has been an increase in multiple births in recent years. Since 1980, infertility treatment has more than doubled the American twin birth rate. The rate of triplet or more births is now nearly 5 times higher than before infertility treatment was used. http://baby2see.com/multiples/multiples.html
There have been an increase because multiple births are related to women having babies later in life.
This is difficult to answer because fashions in names change. For recent births, the most common boy's name is Jack and the most common girl's name is Olivia - but 10 or 20 years ago these names were very rare..
Ozone layer was depleted. It's size has been coming to normal in recent years.
pigw4
Cuba and Southeast Asia have been sources of a large number of political refugees in recent years
Chemical weathering
Yes
Approximately 12% of hospitals in the US allow water births. This percentage has been steadily increasing in recent years as more hospitals recognize the benefits and safety of water birth as an option for labor and delivery.
The overall ratio of live births worldwide is about 1.01 births for boys to 1.0 for girls. That has been the ratio since records have been kept.