From the brightness of the light of course. If the brightness is increasing it means the the light source is approaching and if the brightness is decreasing it means the light source is leaving.
Answer:
If we fail to bring population growth and over-consumption under control — the number of people on Earth is expected to grow from 6.5 billion today to 9 billion by the second half of the 21st century — then we will inhabit a planet where life becomes increasingly untenable because of two looming crises: global heating, and the degradation of the natural systems on which we all depend.
Explanation: hope this helps
It can honestly be all of the above ..