Fossil fuel  

"I was getting the uneasy feeling that green energy was not going to save us."--Jeff Gibbs cited in Planet of the Humans (2019) by Jeff Gibbs

"The 20th century saw the large-scale exploitation of fossil fuel resources (especially petroleum), which offered large amounts of energy in an easily portable form, earning this era the nickname the Age of Oil. This development also caused widespread global pollution and long-term impact on the biophysical environment bordering on an ecocalypse." --Sholem Stein

"In economic terms, pollution from fossil fuels is regarded as a negative externality. Taxation is considered one way to make societal costs explicit, in order to 'internalize' the cost of pollution. This aims to make fossil fuels more expensive, thereby reducing their use and the amount of pollution associated with them, along with raising the funds necessary to counteract these factors." --Sholem Stein