Approximately 300-350 million years ago, seedless vascular plants began growing tall, increasing the global rates of photosynthesis. This caused

Question

A decrease in the levels of atmospheric oxygen

An increase in the levels of atmospheric oxygen

A decrease in the levels of atmospheric carbon dioxide

An increase in the levels of atmospheric carbon dioxide

Global warming

Global cooling

Answer 1

It would have caused a decrease in the levels of carbon dioxide and an increase in the levels of oxygen. During photosynthesis, plants uptake carbon dioxide and they release oxygen. As far as global warming or cooling goes, global cooling is the idea that increased glaciation occurs, but it requires lower amounts of carbon dioxide in the atmosphere to do so. With that being said, the introduction of these vascular plants would have caused the global cooling, not global warming.