This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Net energy cliff. The Net Energy Cliff plot of Energy available for consumption axis vs EROEI axis different energy sources are pictured Coal Legacy Oil and Gas fields Wind Solar etc As EROEI of modern fuels goes down more and more energy of the society is needed to extract new fuels Links theoildrum The Energy Return on Investment