evidence: Climate scientists separate factors that affect climate change into three categories: forcings, feedbacks, and tipping points. Forcings: The initial drivers of climate. [...] - Greenhouse gas emissions. Since the Industrial Revolution, concentrations of greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) have risen in the atmosphere. Burning fossil fuels such as coal, oil, and gas has increased the concentration of atmospheric carbon dioxide (CO2) from 280 parts per million to 416 parts per million.2 These greenhouse gases absorb and then re-radiate heat in Earth’s atmosphere, which causes increased surface warming.