Anthropogenic emission from burning fossil fuel and dumping CO2 to the atmosphere drives the current unprecedented climate change
1. CO2 and many other gases have "greenhouse" properties in that they allow visible light to pass through (hence invisible), but trap and re-emit infrared radiation. This is literally 19th century science, first proposed by Joseph Fourier in 1824, verified and quantified experimentally beyond reasonable doubt by Svante Arrhenius.
2. CO2 in the atmosphere has been rising, and this is a result of fossil fuel combustion (pic related). CO2 can be measured experimentally in the lab, and the stable isotopes of CO2 plunges into the negative values. Fossil fuel has distinct negative isotopic signature compared to natural CO2. This is also an undeniable fact from observation.
3. You add 1+2, you would expect the radiative energy budget of the earth to be out of equilibrium. This is exactly what we observe, based on satellites that measures total energy in vs. energy out by CERES satellite at NASA.https://earthobservatory.nasa.gov/Features/EnergyBalance/page6.phpOn
average, only 71% of energy entering the Earth is leaving. 2nd law of thermodynamics and conservation of energy states that when a system had energy imbalance, T must go up.
In short, CO2 causes greenhouse effect. Humans put CO2 into the atmosphere through fossil fuel burning. The earth is now in energy imbalance due to additional CO2, and therefore warming. All basic, high school physics that should be easy to understand