Humans should start cutting carbon emissions now, even if it is too late to reverse the damage already done. Global warming is caused by humans since the carbon content of the atmosphere is the highest over the past 650,000 years. Even if we aren't 100 percent sure global warming is human caused, we should certainly err on the side of caution and take steps to remedy the situation as soon as possible.
Very true that humans have an impact on the environment and that past temperatures have been warmer than usual, but we need to recognize that the earth is almost like a living, changing creature.
First, the climate is average temperature for an area measured over time. One thing that some people overlook when talking about climate change is that the measurements only go back to the 20th century. The earth is nearly 5 billion years old! I understand that it was cooling and uninhabitable for most of the time but you cannot call rising temperatures in less than 100 years climate change. There have also been three recorded ice ages, of which humans had barely any impact on. The earth heats and cools on it's own. So this whole global warming idea is not really concrete.
Second, switching to "renewable" energy isn't a viable solution at the moment. We talk about switching to eco-friendly energy sources but I don't see it being instigated. The developed and developing world is coal based! There is no way of getting around that. Coal is compressed carbon and contains high amount of chemical energy that is released when burned. Solar, Wind, Hydro and Nuclear energy sources cannot match the same amount of energy without taking up space, or potentially harming the environment which was the goal of these techniques in the first place. Solar renders acres of potentially arable land useless. Wind kills of birds and harms species. If someone in the USA was to kill an Eagle, they would face a major fine and potentially jail time. But if a wind turbine was to kill one, the company who owns the turbine wouldn't have to pay a dime! Hydro is just to expensive to work properly. Nuclear, we all know Chernobyl. That area won't be inhabitable for hundreds of years. Plus all these programs are government subsidized which means tax-payers have to fund these idiotic and horribly planned programs.
The earth allowed life to exists and it knows it can handle it. The idea of change in our world is scary and I understand that. I also understand that sometimes we overreact to change. That's okay, it's human nature. But at one point we need to realize facts and stop trying to fantasize a utopian society.
I might have or might have not change your opinion on this matter, but at least my ideas are out there so that they might help add to your understanding of the topic.