Like conventional wells, the shale wells release methane, which is dangerously combustible, but the new techniques may be more likely to release methane. There are weird reports of methane in the water from faucets in nearby houses catching fire. Fracking has brought such problems to new areas. And methane is a potent source of climate warming if it escapes into the atmosphere.
Minor earthquakes near Fort Worth were widely attributed to fracking in the Barnett shale, and a U.K. firm has acknowledged that “it is highly probable” that tremors near Blackpool, England, were triggered by its fracking activities, which led to a temporary injunction against fracking in the U.K.7 All the earthquakes so far have been very small tremors, but one wonders what calamity might be set loose in a place such as Indonesia, which is in a major earthquake zone and is already a major producer of hydrocarbons, or the Monterey basin in California, close to the San Andreas fault, which is the most promising potential source of shale oil in the U.S. (see below).
The industry vigorously denies that fracking causes more local damage, air pollution, and greenhouse gas emissions than conventional drilling, but that claim is dubious. The huge holding ponds used to store the used fracking fluid alone add a new dimension to the pollution problems. (The exact chemical makeup of the fluid is secret proprietary information, by the way.) Over its life cycle, shale gas may or may not be cleaner than coal or tar sands such as those in Alberta, but that is a theoretical question, since we may anticipate that all exploitable fossil fuels will be used eventually, and thereby contribute their load to climate warming and the environment.
The activity has led to widespread uneasiness. The Council of Scientific Society Presidents in March 2010 warned of the need for much more thorough study of the possible consequences before giving approval to fracking proposals. The EPA on June 23rd announced a major study of the impact of fracking on groundwater pollution.
The uneasiness has led to moratoria or bans in many places, including at least France, Germany, the U.K., Australia, South Africa, Quebec, and several U.S. states.
Will this uneasiness stop or slow down the spread of the technique? It may, in some local situations, but history suggests that such objections are brushed aside when the smell of energy is in the air.
In one respect, the immediate consequences of fracking are already contributing to the larger long term issues. By pushing down the price of gas, the shale revolution is making solar and wind energy projects unviable. That in turn is pushing the development of post-carbon energy sources into a more distant future.
The Uncertain Future. The essential point is that we really don’t know how the future of shale gas and oil will turn out. Bear with me as I present some mutually inconsistent official estimates below.
To take shale gas first: The U.S. Energy Information Administration (DOE/EIA) puts proven U.S. gas reserves at 265 tcf – a new high – 61 tcf of which is shale gas reserves. Total proven gas reserves are expected to rise a modest 19% by 2035.8 EIA expects shale gas production to treble in that period, supplanting conventional sources, but admits to a “high degree of uncertainty”. (“Proven reserves” are not a particularly valuable indicator of the total resource, because they are often not proven until the operators need to validate their presence for operational planning.)
“Unproven recoverable resources” of gas (beyond proven reserves) present a different problem. At this stage, they are hardly more than guesses. The official estimates from the U.S. Geological Survey (USGS) put the total mean undiscovered, recoverable U.S. gas resources at 1025 tcf, nearly twice the estimate made in 1950. Of that, 336 tcf consists of shale gas.9 DOE/EIA cites a much higher figure of 750 tcf for shale gas resources, 86% of which are in the Northeast, with 55% in the Marcellus formation mostly in New York, Pennsylvania and perhaps West Virginia – a much higher estimate than USGS has made.10
EIA is, however, notably cautious about those estimates, pointing out that exploration of the fields is just at the beginning, and much remains unknown about their extent or quality.