The project involved drilling beneath the Earth's crust to gain access to pockets of Stahlman's gas located there, which the project's founder, Professor Stahlman, theorised would provide an endless energy source. Not only did the drilling instead release Stahlman's ooze, which rapidly mutated humans into Primords, but it would also have released enough energy to destroy the planet. The project was shut down thanks to the efforts of the Third Doctor and UNIT, with the aid of project director Sir Keith Gold. (TV: Inferno)
When the TARDIS control console transported the Doctor sideways in time to a parallel universe, the forces unleashed by that Earth's Inferno Project apparently destroyed the planet — or so the Doctor believed. The world was actually devastated beyond recovery, leading the survivors to attempt an infiltration — as there was not enough of them for an invasion — of the regular Earth to take their counterparts' places. (PROSE: The Face of the Enemy)
Later, James Stevens met Greg Sutton and Petra Williams. He interviewed Sutton who, unlike Petra, didn't care much about "pommie D-notices" and thought Stevens wouldn't believe a word of the story anyway. Stevens wrote an article published in the Daily Chronicle that revealed the project to the public.
After the failure of the Inferno Project, among other incidents, was publicised by Stevens in his "Bad Science" series of articles, Harold Wilson's position as Prime Minister of the United Kingdom became untenable and the Labour Party lost the general election in June 1970 to the Conservatives, led by Edward Heath. (PROSE: Who Killed Kennedy)
When Lola Denison announced Project Caldera in her inauguration speech, she described it as a successor to attempts to harness geothermal energy from the Earth's crust in the 1970s. (PROSE: Head of State)
At the conclusion of the Eternal War, after the Engineer created a containment shell around the last hole to the vampires' universe, he told Rassilon that he hoped no one would ever try drilling to the core. (PROSE: Interference - Book One)