What is a light-year?

light year is a unit of astronomical distance equivalent to the distance that light travels in one year, which is 9.4607 ×10^12 km (nearly 6 million million miles).

A light year is a unit of astronomical distance used to measure the distance light travels in one year.

Removing trees  in large amount can cause climate change, extinction of species and hence the food cycle as well as the ecosystems

Explanation:

Deforestation is the major cause of climate change. The atmosphere gets filled with greenhouse gases which would lead to an increase in temperature. We need oxygen to live which is coming from the plants, removing would affect these cycles. several species of animals have been already extinct and continuation of this activity would end up the removal of many organisms from the food cycle and finally, we will be removed.