Personally, I disagree with the doom-sayers that global warming is caused by humans and if we don't do something, we're in for a terrible time. I recently read a QA with economist Holly Fretwell. The entire session can be found here. I will post a few excerpts below:
Q: What do you say is going on with climate change?
A: We do see the Earth is warming. We are coming out of an ice age and we'd expect to see some warming. The Earth has warmed and cooled and warmed and cooled and warmed and cooled many, many times over its history -- long before humans were on Earth and also since humans have been on Earth. We do see a correlation between CO2 in the atmosphere and temperature change in present times and even if we go back into history.
But as any scientist can tell you, correlation is not causation. We need to be very careful about that. We have a lot of people out there trying to tell us that because one thing is happening, it's causing another thing, when, in fact, we really don't know that. There's a lot of uncertainty out there.
If you actually go back and look at the data that shows CO2 levels and temperature changes over the last 650,000 years, what we find is that temperature actually changes first and CO2 in the atmosphere follows that temperature change. Maybe I should say that again: Temperature changes first. CO2 lags the temperature change. We know that humans are emitting CO2; the point being, however, there is no reason to believe that CO2 is causing temperature change when it is following temperature rises over the history of the data we have.
Q: There is a lot of science that we don't know yet, as you stress in the book. And you also stress that we shouldn't panic, like Chicken Little, but try to understand what is really happening and why it is happening. What's the most important thing about global warming that we still don't know?
A: Why climate changes. We really don't know. We know so much, and we have so many ideas of why climate changes and how all these different factors may impact climate. But we really don't understand how they all work together or which ones override the others. We're talking about the energy that's coming from the sun, the way the Earth travels around the sun; we have all sorts of cycles like Milankovitch Cycles, etc., that have some impact on the climate.
Q: Do you have a favorite example of something that was invented -- like the air conditioner example in your book -- that shows how markets and human ingenuity can solve some of these global warming problems better than governments?
A: I have more general examples than a very specific example, and that is, as developed countries become more developed and wealthier, we've been able to spend a lot more money and we've focused a lot more on cleaning up our environment. This is pretty common and it makes a lot of sense; it's fairly intuitive sense. As we become wealthier we are not so concerned with feeding ourselves, getting shelter and feeding our children. Now we have a little bit more disposable income. We've taken care of some of those crucial issues to life, and now we can take some of our resources and start thinking more about our longevity and some of the amenities that exist around us. We want cleaner air, we want cleaner water, both because it makes us live longer but because it is more enjoyable.
If we can't pay to put food on our table, we don't have any money to be concerned with those issues. Taking care of our basic needs is really important, and beyond that, then we can start thinking about the environment. Developing countries like China and India, they are still trying to take care of their basic needs. It's really hard to get them to start thinking about taking care of their environment when they can barely put enough food on their table to feed themselves. So to me, this is one of the places where we've seen example after example of markets being very effective at improving people's wealth and well-being far better and far faster and far more effectively than command-and-control societies.
Human-caused Global Warming Resources
An Inconvenient Truth
Naturally-caused Global Warming Resources
The National Center for Policy Analysis - Global Warming Primer
The Great Global Warming Swindle
The Politically Incorrect Guide to Global Warming