It is not clear whether Pennsylvania has enough of the deep geological formations necessary for such disposal.

WSJ: Daniel Yergin on the Shale Gas Revolution: Stepping on the Gas

Next, geologists and petroleum engineers huddle in a "hive, " a 3-D imaging room, to identify promising geological formations and plan the trajectory of the well.

FORBES: The delicate art of sucking up

As for the ability of geological formations to retain carbon dioxide, the IPCC has concluded that retention will likely be 99% or more over 1, 000 years.

ECONOMIST: The benefits of CCS

The criteria considered include population density, the distance to underground geological formations suitable for carbon sequestration, seismic activity, terrain, proximity to airports, military bases and so on and so forth.

FORBES: Plotting The Next-Generation U.S. Power Grid

If the demonstration plant works as well as hoped, the plan will be to build combined electricity and hydrogen generating stations in locations where there are geological formations containing saline water overlain by a thick caprock serving as a seal.

ECONOMIST: Tech.view

Innovations like hydraulic fracturing, known as "fracking, " have made it easier to extract oil and especially natural gas from energy-rich geological formations such as the Niobrara shale, which stretches from Wyoming to beneath the densely-populated Front Range of Colorado's Rocky Mountains.

WSJ: As energy boom nears cities, a backlash grows

The Geopark highlights the geological values of the region which testify to a rich geodiversity of sharp cliffs and hot springs, volcanoes and basalt columns set against a diverse geological and morphological mosaic of different formations.

UNESCO: MEDIA SERVICES

Geological surveys show America has enough saline rock formations to store three trillion tons of carbon dioxide enough for the next 500 years at the country's current output from human activities.

ECONOMIST: Tech.view

Set in the Apennine mountains, the Geopark offers rich geological diversity and outstanding sites of mountainous landscapes, cave formations and coastal features.

UNESCO: NATURAL SCIENCES