Solar radiation travels through the earth's atmosphere and warms the planet's surface. greenhouse gases like carbon dioxide in the earth's atmosphere reabsorb the heat and warm the planet. the amounts of greenhouse gases have been increasing over the past century, causing the earth's surface temperature to increase. this gradual temperature change is thought to have many negative environmental consequences.

which of these might be a positive effect of the increase in carbon dioxide levels?

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.