5. Solar impacts on Earth

‘Solar impacts on earth’ focuses on space weather—rapidly changing conditions in the earth’s ionosphere and above. The Sun’s natural tendency to emit variable high energy radiation causes problems for us that it did not for our ancestors, as eruptions and storms interrupt our dependence on electronics. The ‘faint young sun’ paradox arises from the idea that the newly formed earth only received two-thirds of the Sun’s radiation today, yet water formed on earth without freezing; popular explanations include the Sun losing mass with age or an increase in greenhouse warming or radioactive heating. There seems to be no heating trend in the Sun correlating with recent global warming.