When the combustion engine was invented it had many positive effects on society, but years later it has been discovered that the burning of oil and coal has major negative effects on the environment. What is that negative effect?

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.