human activity has negligible impact on the climate.
This is demonstrably untrue.
There is zero evidence for it.
There is mountains of evidence for it.
You need to understand that the earth’s climate changes naturally and the earth’s climate is variable.
You need to understand that literally nobody is arguing otherwise.
You also need to understand that the current rate of change vastly exceeds anything seen in Earth's history as a life-bearing planet, outside of mass extinction events; And that the only plausible explanation for the rapidity of the current change is the burning of fossil fuel by humans since the Industrial Revolution.
That you do not understand these things shows a remarkable resistance on your part to learning facts about reality. It's not like the evidence is hard to find. Or like the theoretical underpinning is complex.
If you burn fossil fuel, carbon that has been locked away underground for millions of years is released into the atmosphere as carbon dioxide. Carbon dioxide in the atmosphere traps heat. We have burned a huge quantity of coal, oil, and gas. As a result, global average temperatures are rising rapidly - more rapidly than at any time in geological history (other than during mass extinction events).
That's it. What part of that do you dispute, and what is the contrary evidence? Be specific.