Does lightning have a beneficial effect on the earth?

Answer 1

The main effects on the earth by lightning is the production of forest fires and also the production of nitrate fertilizer into the soil. In one year lightning produces about 250,000 tons of usable nitrogen fertilizer. When people did not inhabit parts of the earth, or did not use fire, almost all forest fires were caused by lightning. Nowadays, most forest fires are caused by people. After a forest fire, when vegetation and trees grow back, the growth is strong and lush. The reason for this is probably twofold. The burnt plant matter is mineralized and becomes very good fertilizer for future plant growth. Additionally, old trees and vegetation gets burnt and removed, making room for new and possibly vigorous growth. This can function in a positive evolutionary way, since it provides a way for new plants and vetgetation to develop and even evolve. It gives evolution a better chance to work. However, these days with a high population of humans on the planet, there seem to be far too many forest fires. Many, or even most fires are deliberately set by thrill seekers or immature persons. It would seem that the effect of fires caused by lightning was more beneficial to the earth in the past when the human population of the earth was very low. In addition, the use of manmade nitrate fertilizer is much greater than that produced by lightning. A thunderstorm and lightning can produce negative ionization of the air, and it is claimed by some that this may improve a person's mood.

Answer 2

Lightning 'fixes' the nitrogen in the atmosphere, turning it into a form that can be used by plants and, eventually, by us. It is estimated that half the the naturally available nitrogen is made by 'nitrogen fixing bacteria' in plant roots. The other half is made by lightning.