The quote states that we should be using solar energy before our limited amount of naturally occurring oil and coal runs out. Meaning; we should be proactively working towards solar power rather than to wait for our resource to run out to start.
The correct answer is - cyanobacteria.
The atmospheric oxygen came from the cyanobacteria. These were one of the earliest living organisms on Earth. The cyanobacteria was using photosynthesis in order to create its own food. The photosynthesis process requires sunlight, carbon dioxide, water, and oxygen. The oxygen is mostly released as a waste product from the process of photosynthesis, thus the cyanobacteria were literally releasing oxygen that was ending up into the atmosphere. As more and more cyanobacteria there were across the planet, more and more oxygen they were releasing into the atmosphere, slowly changing the composition of the atmosphere, and setting the basis of it as we know it now.
It is showing the most populated areas at that time range
Global warming which is not a geological process but something humans have caused
