It was true in the context of finding the Higgs boson. They couldn't do it until they were able to accelerate particles to sufficiently high energies (near the speed of light accelerating particles doesn't change their speed much but rather just give them more kinetic energy (it increases their mass)). This is the science chapter after all.

Also if we intend to continously increase the worlds population there is no limit to how scarce resources we will have to tolerate. Put in other words: however little energy (or any other resource) each one uses it will be too much at some population level.