What might effect the global food webs if the sun's energy could no longer reach Earth?

If the sun's energy could no longer reach Earth, it would lead to a dramatic drop in temperatures, causing most plant life to die off due to the lack of photosynthesis. This collapse of primary producers would disrupt the entire food web, leading to the extinction of herbivores and, subsequently, carnivores that depend on them. The loss of energy from the sun would result in a barren landscape, severely limiting biodiversity and altering ecosystems drastically. Ultimately, the interconnected relationships among species would unravel, leading to a collapse of most life forms on the planet.