Why?
1. Too many lies. In the 80s the water level was rising, but it didn't. Then acid rains would kill all, but did not. Then ...
2. I cannot change it. Using fossils (or other tech with big "environmental" impact) is a great way to scale business. The "economy God" is to important to actually go an fix the problem. That why we see no real solutions being implemented and climate agreements being ignored/ not signed.
3. The focus on CO2 is stupid. There are worse problems: fine dust, pollution, disruption of ecosystems. But we now totally focus on CO2 (or CO2-equevalents).
I do have a solution. Remove (gradually) all taxation, in favor tax on pollution and usage of particular scarce resources (e.g. land, water, fossils, radio frequencies, etc.) This way the market will solve the problem. Housing and labour (two examples of wholesome things that are currently heavily taxed) will become a lot cheaper, and polluting will become expensive.
Capitalism has shown itself to have a complete inability to correctly price in the value of ecosystem services and the costs of environmental externalities. The profit cycle also operates on too small a timeframe for these climate issues.
Thinking the market will save us is just a convienient pipe dream.