So, in one hour, the Earth receives more energy from the sun than us humans generate in an entire year. If we took all of the energy we generated over a year (and not just the waste heat) and converted it into heat, we wouldn't even be adding half of one percent to the system. Our direct contributions to the system are minuscule. The problem is we're pumping out green house gasses like there's no tomorrow. And those directly increase the amount of solar energy the Earth retains. And when we start keeping 1 or 2 more percent of that insane amount of solar energy, it adds up really, really fast.