What should I do to decrease the temperature from the Cryogenian period? ​

Cryogenian Period, second of three periods of the Neoproterozoic Era of geologic time, extending from approximately 720 million to approximately 635 million years ago. The Cryogenian Period followed the Tonian Period (which lasted from 1 billion to about 720 million years ago) and was succeeded by the Ediacaran Period (approximately 635 million to approximately 541 million years ago). The beginning of the Cryogenian Period was defined arbitrarily: that is, it corresponded to the onset of the first glacial episode to follow the date of 750 million years ago.

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.