Question

Which human activity has aggravated the ecological issue of global warming?

Answer 1

Yes. There is a natural warming of the earth from the greenhouse effect, supported by the water and carbon cycles, but that has been keeping the earth warm for millions of years.

The present global warming, which began at the start of the Industrial Revolution (1750s) was just the time when we started to seriously dig up coal and cut down forests. Burning fossil fuel (coal, oil and natural gas) releases carbon dioxide, a powerful greenhouse gas, that has been hidden underground for 300 million years. Cutting down the forests (deforestation) destroyed the great carbon sinks that (through the process of photosynthesis) could soak up carbon dioxide out of the air, release the oxygen and store the carbon. Half the weight of a tree is carbon.

So it is the increased levels of greenhouse gases in the atmosphere, much more than the natural carbon cycle can deal with, that are the problem. Carbon dioxide in the atmosphere has increased 40% since the beginning of the Industrial Revolution, and it stays there, catching more and more of the sun's heat and causing global warming.