The phenomenon of shale gas not only threatens the quality of water in local ecosystems, but is also a threat for climate change.  In Latin America, a number of countries are moving towards the exploration and exploitation of these resources, especially in shale gas, without considering these threats.

The world is now the scene of the so-called "shale revolution", a global phenomenon made possible thanks to the development of technologies for exploiting hydrocarbons that allow for access to resources that were previously inaccessible. This has increased the available volume of gas and oil, considerably increasing the reserves of fossil fuels.

Nevertheless, there is a generalized agreement, at a world level, concerning the threat of climate change from the use of these resources as fuels. There is also an unresolved academic debate concerning the levels of emission per unit of energy from the life cycle of such non-conventional hydrocarbons.

These non-conventional hydrocarbons are not intrinsically different from the conventional ones. The difference lies in the kind of geological formation in which they are found and the technologies required for their exploitation. The decline of conventional deposits in the face of an increasing demand for energy has led to the development of these new technologies.

According to the report of the International Energy Agency (IEA 2013), the recoverable resources of petroleum continue to increase as technologies allow the exploitation of crude, such as the light tight oil or shale gas, which were not regarded as recoverable until recent years. The latest estimation of recoverable petroleum resources indicates that there are 2,7 trillion barrels of conventional petroleum, 345 billion of light tight oil, 1,8 trillion of heavy petroleum and 1 trillion barrels of shale oil.  In the case of natural gas, recoverable resources amount to 950 trillion cubic meters, of which 270 are non-conventional.

The agency has elaborated a scenario of "New Policies" which in contrast with the "Current Policies" (tendential or "Business as Usual") include measures that countries are considering in order to reduce their emissions of greenhouse gases. In this scenario of new policies, the quantity of petroleum needed to meet the demand from now until 2035 are some 790 billion barrels, less than one sixth of recoverable reserves. In the case of natural gas, the total demand during the same period is 10% of recoverable reserves.

Hence, one can conclude that the world could satisfy its energy needs at least until 2035 without exploiting non-conventional resources. In spite of this, within that same scenario, the emissions of the energy sector will grow some 20% with respect to the present, reaching 36 GtC02. In this case, the average temperature of the planet would increase 3.6º C with respect to the pre-industrial era, well over the agreed limit of 2º C. If the "new" policies are not introduced, the most preoccupying scenario involves global emissions of 64 GtC02 and a temperature increase of up to 7º C.

Shale emissions

Although there are differences between estimates, all of them indicate that the exploitation of non-conventional resources, both of petroleum and of natural gas, produce greater emissions of greenhouse gas than the conventional ones in the upstream, that is, in the stage of exploitation. During their consumption, the differences depend on the technologies involved, for example open or closed cycles for electrical generation. In some cases, the emissions of shale gas are greater than those of coal.

The "shale revolution" and the exploitation of non-conventional hydrocarbons generally lead to a greater level of emissions of greenhouse gases. These emissions will largely surpass the 2º C temperature increase. This increase may be influenced by greater emissions over the life cycle of non-conventional hydrocarbons as compared to the conventional ones.  However, the principal reason for this is the great volume of recoverable resources added to exploitable reserves. In the reports on this, the conclusion is unanimous: the greater part of these resources should remain underground if the intention is to limit the average temperature increase to 2º C.

The time available for energy reconversion is limited. Investments made during the present decade will condition the energy patterns for a number of years, so that a reduction of emissions compatible with a secure climate scenario becomes more difficult and more expensive.  The majority of the recoverable non-conventional resources will still be available, after various years of investment, when it will no longer be possible to use them within a trajectory of emissions that will keep us below the 2ºC limit.

Beyond the extended and documented local impacts of the production of non-conventional hydrocarbons, the inconvenience of continuing to expand the frontier of reserves for a world that cannot use them is obvious. This is especially the case when one considers that conventional reserves are sufficient to reach the year 2035, and that beyond that date the planet should be ready for a life without fossile fuels, as the G7 countries have declared.

(Translated by Jordan Bishop for ALAI)

- Gerardo Honty is an analyst with CLAES (Centro Latino Americano de Ecología Social).

This article presents the conclusions of the book “Potenciales emisiones de la explotación de hidrocarburos no convencionales” (Potential Emissions from the Exploitation of Non-conventional Hydrocarbons) available at  http://energiasur.com/emisiones-del-fracking