Plants and animals depend upon each other as mutual interdependence is must for their survival. Plants provide shelter for animals and they make oxygen for the animals to live. When animals die they decompose and become natural fertilizer plants. Plants depend on animals for nutrients, pollination and seed dispersal.
Earth’s global temperature has changed greatly in the past hundreds of years. This is due to how much energy the planet is receiving from the sun and how it radiates back. Another cause is humans, due to deforestation, burning of fossil fuels, pollution, etc.