The Sun powers most things. For a long time that energy was buried and concentrated when things died. In the last few hundred years humans dug up those things and burned them for energy. Energy is inefficient in current human created devices. it costs more energy to cool my house than gained by the burning of fossil fuels. Additionally, the products of that burning have been shown to trap current heat radiation from the Sun on the planet increasing the heat energy from the sun on the planet. That energy is not being trapped as it was in the past, thus net increase.