Global warming is largely due to this increase in atmospheric carbon dioxide. Explain how increases in atmospheric carbon dioxide concentrations contribute to global warming. ​

Humans have been artificially raising the concentration of greenhouse gases in the atmosphere at an ever-increasing rate, mostly by burning fossil fuels, but also from cutting down carbon-absorbing forests.

Concentrations of carbon dioxide and other greenhouse gases in the atmosphere have increased since the beginning of the industrial period which lead to the Global Warming and it also causes the depletion of Ozone layer

explanation:

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.