That's a valid objection. Not neccessarily true, but valid. The cost/benefit ratio must be calculated. Some things will prove easy, cheap and will provide immediate short-term improvements in carbon output, like better stack scrubbers. This helps overall pollution, too. None of us want to live or die in a polluted land.

Other expensive solutions that will take several centuries to show results are a waste only because we will be out of oil in 60 years and out of coal in 200 years. We simply won't have fossil fuels to burn anymore. It is inevitable that emissions will decrease after that point.

What is an invalid objection is to say that the entire science of climatlogy is wrong and that global warming has to be bullchit because common sense tells you that 2 degrees doesn't seem like a lot. Well, daily temperature and global climate are two very different things and 2 degrees of global temperature rise is significant, whether you understand it or not.

If you take nothing else away from this argument, try to grasp that just because some of the politics and proposed solutions to climate change are untenable and subject to criticism, that doesn't disprove the science behind what is happening one single bit.

Nor have you. Do so and I will evaluate it.

Disproved repeatedly. Climate science is in consenus on this matter. The existence of dissenting opinions does not affect this.

I don't know if there is a meaningful way to define an "optimum" average temperature for planet earth. Surely it is better now for all of us than it was 20,000 years ago when so much land was trapped beneath ice sheets. Perhaps any point between the last ice age and the extreme one we may be heading for, with tropical forests inside the arctic circle, is as good as any other.

It doesn't matter. The critical issue is not what the temperature is, or may be, or will be. The critical issue is how fast it is moving.

Rapid change is the real danger. Human habits and infrastructure are suited to particular weather patterns and sea levels, as are ecosystems and animal behaviors. The rate at which global temperature is rising today is unique in the history of our species.

How many billions? How many lives? Pick a number, there are plenty of estimates and studies out there. My point is that 2 degrees (Celcius, of course, 3.6 degrees F) of global climate change is significant.

An increase of a few degrees won't simply make for pleasantly warmer temperatures around the globe. In the last 10,000 years, the Earth's average temperature hasn't varied by more than one degree Celsius. Temperatures only one to five degrees Celsius cooler than those today prevailed at the end of the last Ice Age, in which the northern United States was covered by more than 3,000 feet of ice.