I'll steer it back on topic with a basic primer:
CO2 is a greenhouse gas. Greenhouse gases are gases that, when present in the atmosphere, warm our planet. When you add more greenhouse gases than what the Earth is capable of absorbing, then this will increase the amount of greenhouse gases present in our atmosphere, which, in turn increases the planet's temperatures.
Currently, the Earth and life on it naturally emits 770 gigatons of CO2 every year and absorbs 790 gigatons of CO2. If you do the math, this should result in a net DECREASE of CO2 of 20 gigatons every year, and, therefore, set the Earth on a cooling trend. More on this later.
However, human fossil burning and land use artificially pumps an additional 30 gigatons of CO2 every year. So now, again, doing the math, this results in a SURPLUS of 10 gigatons of CO2 every year, instead of decrease that was supposed to be happening naturally. Therefore we are artificially warming the planet.
Here is a chart that shows how CO2 correlates with global temperatures.
So, now that's been established, how much are we warming the planet?
Today the average global tempurature anomaly has reached close to 1.5 degrees Celsius, so you can see the alarming rate in which man-made CO2 emissions have warmed the planet. The real danger is once this hits 2.0 C, when scientists warn of catastrophic dangers worldwide that would result. We are not far behind.
Is this all part of the Earth's natural cycle? Let's take a look:
As you can see, we were quite due a cooling trend. And, indeed, from this closer look below of the last two thousand years, we see it taking place.
However, this natural cooling trend was abnormally and sharply interrupted starting at around the mid-1800's.
Guess when the Industrial Age began.