Answer to Question 1
When the Sun first formed 4.6 billion years ago, it is believed to have been about 30 less luminous than it is today. The Sun's luminosity increased slowly at first and then more rapidly as the buildup of helium in its core continued. At present, the Sun is thought to be brightening by about 1 every hundred million years.
Answer to Question 2
Stratosphere ozone is important to living organisms because it absorbs many of the Sun's harmful ultraviolet rays. Ultraviolet radiation causes skin cancer and other health problems in humans.
Past and current ranges of the grizzly bear.
Discipline-specific training can take years to perfect.
Past Vegetation
Wind, solar, biomass, and geothermal power account for less than 1% of global power generation
Solar updraft towers
Three years old drawing