Fossil fuels are non renewable resources. They cause carbon dioxide to be trapped in the atmosphere (because not all of it can be absorbed fast enough) which breaks down the layers protecting us, and heats up the earth causing global warming.
A renewable resource is geothermal energy. This is when the heat from the earth is turned into electricity. Air emissions are minimal in this situation because they are pumped right back into the ground. It overall doesn’t have many NEGATIVE impacts. Some positive ones are that it doesn’t create much waste to the environment and we won’t run out of it