The environmental costs and benefits of fracking

Unconventional oil and natural gas extraction enabled by horizontal drilling and hydraulic fracturing (fracking) is driving an economic boom since it generates income and can reduce air pollution and even water use compared with other fossil fuels. Alternatively, fracking could slow the adoption of renewables and release toxic chemicals into water and air. An increase in VOC and air toxics locally are potential health threats, but the switch from coal to natural gas for electricity generation will reduce S, N₂, Hg, and particulate air pollution. Data gaps are particularly evident for human health studies, for the question of whether natural gas will displace coal compared with renewables, and for decadal-scale legacy issues of well leakage and plugging and abandonment practices.