Final answer:
Without visible light from the Sun, Earth would face severe repercussions, including impaired photosynthesis, reduced temperatures, human blindness during the day, and possible advantages for infrared-sensitive organisms.
Step-by-step explanation:
If the Sun emitted infrared and other types of light but not visible light, several significant changes would occur on Earth. First and foremost, plants would struggle with photosynthesis, since most plants are adapted to use the visible spectrum, particularly the blue and red wavelengths, to drive this process. No plants mean no food for animals and a collapse of the food chain. Secondly, Earth's temperature would likely drop since the warmth we enjoy is significantly from the sun's visible light.
Humans would not be able to see sunlight, resulting in a world plunged into darkness, affecting not only sight but many aspects of human life, including vitamin D synthesis, which is essential for bone health. Lastly, animals that can detect infrared radiation might thrive or at least maintain some ecological niche, as they can detect heat emitted by prey or the environment.