"In 2019 there were about 7.7 billion humans on Earth, more than double the number of people alive in 1969. During that fifty-year period the impact of humanity on the natural environment has increased proportionately. human activity is causing a loss of biodiversity-the diversity of plant, animal, algae, fungi, and microbe species. But the survival of humanity-and all life on earth-is directly related to biodiversity"-- Provided by publisher.