What are two sources of energy for the earth sytem?

What is the name given to Earth's first atmosphere? Why can magnesium metal be shaped? What is a broad flat area of land higher than the surrounding land? What are the 3 main types of heat transfer and how are each of the different? What do you call a flat deposit of rocks? What type of weathering is caused when rocks sit in a pool of salt water? What do the farmers do to aerate the soil? What is the opposite of above sea level? How does slaked lime help in the treatment of acidic soil? Can nitrogen be broken through ordinary chemical means? WHY ammonia has higher boiling point then phosphine? What are the number of carbon atoms and oxygen atoms in 2 molecules of carbon dioxide? What are the ways to protect soil resources? An epic is most likely associated with? What to wear at 0 degrees celsius? What colour is the precipitate sodium phosphate and ammonium molybdate form? Why is so much basaltic magma erupted along mid-ocean ridges? What are the names of the organic sedimentary rocks? Why isn't soil living? Why the first ionisation energy of O is less than that of N?

What are two sources of energy for the earth sytem?