Empirical evidence that humans are causing global warming

How do we know that’s it’s those billions of tons of carbon dioxide that are being emitted annually by humans and the overall several hundred billion tons that have been emitted by us humans in the last couple of centuries that are responsible for global warming? Look at the empirical evidence.
https://www.skepticalscience.com/empirical-evidence-for-global-warming.htm

The final piece of evidence is ‘the smoking gun’, the proof that CO2 is causing the increases in temperature. CO2 traps energy at very specific wavelengths, while other greenhouse gases trap different wavelengths. In physics, these wavelengths can be measured using a technique called spectroscopy. Here’s an example:
The graph shows different wavelengths of energy, measured at the Earth’s surface. Among the spikes you can see energy being radiated back to Earth by ozone (O3), methane (CH4), and nitrous oxide (N20). But the spike for CO2 on the left dwarfs all the other greenhouse gases, and tells us something very important: most of the energy being trapped in the atmosphere corresponds exactly to the wavelength of energy captured by CO2.
We know with a very high degree of certainty that it's carbon dioxide that is responsible for the significant warming of the Earth that has occurred in the last and this century because the increases in heat being redirected back to the Earth's surface are mostly in the spectrum of energy captured by CO2. And we also know that humans have and continue to emit massive amounts of CO2 into that same atmosphere. It's not the clouds, it's not the Sun, it's not ocean currents or some nebulous "cooling" cycle that deniers keep trying to conjure out of thin air to explain the growing and very serious changes on Earth. What's happening now to the global climate is the result of a dramatic increase in the amount of carbon dioxide in the atmosphere caused by us humans burning billions of tons of coal, oil and gas. And when that CO2 is added to the atmosphere it enters an environment where there are huge amounts of heat constantly attempting to transit from the Earth's surface through a gas and escape into space. The more CO2 we add the more of this gets intercepted and sent right back at us. The evidence is very clear...