Yes CO2 has been higher in the past then what they are now, but something you seem to be ignoring is that it took hundreds of thousands or even millions of years to build up to those levels. Which gave the plants and animals time to evolve to accept those levels. Thats why you don't see mass extinctions due to those levels. It also takes hundreds of thousand to millions of years for those levels to come down.
We were coming out of the end of an ice age not in the midst of one.
In the past 200 to 300 years CO2 has doubled from what it was. The only real thing that has changed in that time is man with all the burning we are doing along with all the environment destruction and cutting down of rain forests that we have done in that time.
Renewable resources are actually the future. That includes solar and wind, geotherma, waves, tidal, hydro and a number of other things. These are not being forced onto people, they are how ever giving people more choice. If we can stop using coal and oil and gas burning power plants then whats so wrong with that?
And yes any new tech is expensive but with time it does come down in price. Solar for example is just a fraction of what it used to cost. The more people that use it, the cheaper it will become because there will be more demand for it.
And an average person not being able to afford to buy or benefit from a million dollar wind turbine doesn't mean squat. They can't buy or benefit from a multimillion dollar power plant either. In my area we only have 1 power company and they have a coal/gas fired power plant and every single year they raise the cost of power. They are making large profits and just last year gave all their execs a 50% raise.
The average person is how ever getting closer to being able to afford a decent solar and small scale wind turbine setup which can pay for itself within 10 years. If every new home built included solar panels that would help bring the panel prices down.
If governments stopped giving billions of dollars to oil companies who don't need those billions because they are making 10s of billions in profits and put those billions towards renewable resources such as solar and wind those prices would come down very fast and we could rely less on coal/gas/oil power planets. If we take even just a billion of that money going to oil companies and put it towards say wind turbines which cost around 3 million each, that could be around 333 new wind turbines that could be built and installed basically free each and every year. Thats 1400 (roughly) households that could get their power cheaper per turbine or around 466,200 households per for all those turbines.
About 10 years ago, I figured that it would take about 50,000 dollars to put enough solar panels on my roof to virtually pay for all the power I use in a day (that includes install costs). If we again take that billion dollars and have all those panels put on homes, that could be around 20,000 homes a year they could put solar panels on free of charge. If those homes are low income homes, that suddenly means all those families have far more income per month to spend on other stuff, which also bring in more money for the government either because they don't have to give out as much or because they are taking more in from taxes. Also in the last 10 years, I'm pretty sure prices have dropped quite a bit so really even more houses could be covered.
Course some laws would have to be changed, power companies would have to be forced to accept extra power from homes that produce more then they are using and unless those houses also have lots of batteries they would still need to have some sort of power source at night, but thats where the other renewable resources come in.
Now imagine if we took all the money the government gives or subsudizes the oil companies (which is somewhere around 10 billion dollars last I read) was used to put renewable resources in for use by low income housing. The economy and environment would be far better off in the long run. If they would have started doing this 15 or 20 years ago things would be better now.
Also there are catastrophic warnings going on now, for what will happen in the near future because today we are seeing stuff we have never seen before in recorded history. Glaciers that have been recorded for hundreds of years have disappeared, the majority of them are all melting at very high rates. Areas where we have never seen the ocean due to ice coverage are now showing as ice free for part of the year and that time is lengthening each year. Pictures going back 100 years showing the same location and same time of year show open areas where as the older images show more and more ice the further back you go.
People have been warning about climate change for a long time, the late 1800s and early 1900s.