Imagine That, Similar to Events That Occurred 65 Million Years

Essay

Imagine that, similar to events that occurred 65 million years ago, a huge meteorite were to hit Earth tomorrow, spewing cloudy debris into the atmosphere and blocking a large proportion of sunlight. Because plants rely on sunlight, global rates of photosynthesis would be greatly reduced, and many of the animals that depend on photosynthetic plants (such as herbivores and the predators that feed on those herbivores) would starve or go extinct.
In this scenario, why canʹt the plants continue to produce sugars and survive if the sugar-producing reactions in photosynthesis are considered ʹlight independentʺ?