of those 15,000,000,000,000 watt-hours
come from carbon-based fuels
(coal, petroleum, natural gas);
that produce carbon dioxide when burned.
Only 14% is NOT carbon-based.
1. What are these consequences and why are they so serious?
2. 15,000,000,000,000 sounds big. How much is it?
3. Why are coal, oil, and natural gas called carbon-based?
4. What is carbon dioxide? Where does it come from?