Shale gas is a game-changer for global energy supply. It is already transforming the U.S. energy outlook, and is expected to deliver over 40% of domestic gas production by 2025 (Figure 1). Other countries and regions, notably Europe and China, may soon follow suit, in a repeat of the early 20th century oil rush.
Opinion is bitterly divided, however, over the environmental risks and benefits of this abundant new source of energy – so much so, that the different sides struggle to agree even on basic facts. The debate is raging over two key issues – on-the-ground impacts to water, air, communities, land use, wildlife, and habitats; and the broader energy and global warming implications of developing shale gas.