Why is climate change happening?
Climate change is happening primarily because the burning of fossil fuels — coal, oil, and natural gas — releases carbon dioxide and other greenhouse gases that trap heat in Earth's atmosphere. Since the Industrial Revolution, human activities have increased atmospheric CO2 by over 50%, raising global temperatures at a rate unprecedented in geological history. Deforestation, agriculture, and industrial processes contribute additional emissions.
Climate change is happening because of a well-understood physical mechanism — the greenhouse effect — that human activities have dramatically intensified. The science is straightforward; the political challenge of addressing it is anything but.
Earth's atmosphere naturally contains greenhouse gases — primarily water vapor, carbon dioxide, and methane — that trap some of the sun's heat, keeping the planet warm enough to support life. Without the natural greenhouse effect, Earth's average temperature would be about -18 degrees Celsius instead of the habitable 15 degrees Celsius. The problem is that human activities have dramatically increased the concentration of these gases, trapping more heat and warming the planet beyond its natural equilibrium.
The primary driver is burning fossil fuels. Coal, oil, and natural gas are carbon-rich substances formed from ancient organic matter over millions of years. Burning them releases that stored carbon as CO2 in a geological instant. Since the Industrial Revolution began around 1760, atmospheric CO2 has risen from roughly 280 parts per million to over 420 ppm — a 50% increase. This is unambiguously caused by human activity, confirmed by isotopic analysis of atmospheric carbon that bears the chemical signature of fossil fuels.
Deforestation compounds the problem. Forests absorb CO2 through photosynthesis — they are carbon sinks. When forests are cleared — for agriculture, cattle ranching, logging, or development — not only is this absorption capacity lost, but the carbon stored in trees is released. Tropical deforestation alone accounts for roughly 10% of global greenhouse gas emissions. Agriculture contributes through methane from livestock and rice cultivation, and nitrous oxide from fertilizer use.
The warming is amplified by feedback loops. As Arctic ice melts, it exposes dark ocean water that absorbs more heat than reflective ice, accelerating warming. As permafrost thaws, it releases stored methane — a greenhouse gas 80 times more potent than CO2 over 20 years. Warmer oceans absorb less CO2. These feedbacks mean that the climate system can reach tipping points beyond which warming becomes self-reinforcing, regardless of human emissions reductions.
The scientific consensus is overwhelming — over 97% of climate scientists agree that human activities are causing global warming. The evidence comes from ice cores, ocean measurements, satellite observations, temperature records, and basic physics. The question is no longer whether climate change is happening or why, but whether humanity will act quickly enough to prevent its worst consequences.