4. Underline the key points in the following text.
THE SIXTH WAVE?
Lord May, the president of the Royal Society, has claimed
that the world is facing a wave of extinctions similar to the
five mass extinctions of past ages. He calculates that the
current rate of extinction is between 100 and 1,000 times
faster than the historical average. The cause of previous
extinctions, such as the one which killed the dinosaurs,
is uncertain, but was probably an external event such as
collision with a comet.
However, the present situation is caused by human
consumption of plants, which has resulted in a steady
increase in agriculture and a consequent reduction in
habitat for animals. Although many people are still hungry,
food production has increased by 100% since 1965.