- Howarth_Ingraffea_-_4th_Anniversary_lecture_at_Cornell_University_-_April_14_2015-

(2002), conventional 1.3 % 2.5 % 3.8 % EPA (2010), US average for 2009 0.16 % 0.9 % 1.1 % Howarth et al. [...] (2011), US average 1.7 % 2.5 % 4.2 % conventional gas 1.3 % 2.5 % 3.8 % shale gas 3.3 % 2.5 % 5.8 % EPA (2011), US average for 2009 1.8 % 0.9 % 2.7 % conventional gas 1.6 % 0.9 % 2.5 % shale gas 3.0 % 0.9 % 3. [...] (2002), conventional 1.3 % 2.5 % 3.8 % EPA (2010), US average for 2009 0.16 % 0.9 % 1.1 % Howarth et al. [...] (2011), US average 1.7 % 2.5 % 4.2 % conventional gas 1.3 % 2.5 % 3.8 % shale gas 3.3 % 2.5 % 5.8 % EPA (2011), US average for 2009 1.8 % 0.9 % 2.7 % conventional gas 1.6 % 0.9 % 2.5 % shale gas 3.0 % 0.9 % 3. [...] (2011), US average 1.7 % 2.5 % 4.2 % conventional gas 1.3 % 2.5 % 3.8 % shale gas 3.3 % 2.5 % 5.8 % EPA (2011), US average for 2009 1.8 % 0.9 % 2.7 % conventional gas 1.6 % 0.9 % 2.5 % shale gas 3.0 % 0.9 % 3.