It was recently Earth Day, so many had to "think green" because of environmental concerns. The biggest concern recently has been with the levels of CO2 in the atmosphere. There is usually some level of equilibrium on sufficiently large scales of the gas in the atmosphere between production and consumption by things on earth, both biological and geological. If such an equilibrium were to be thrown off enough, it could lead to a warming trend in world temperatures which can lead to significant climatological problems for things that depend on its current state, including us humans. Human activity with the burning of fossil fuels, which return much of the stored carbon in the earth back into the atmosphere , has raised CO2 levels to a higher level than has been seen in history and far into prehistory.
It is the strong consensus of climatological scientists that CO2 levels have increased and are causing changes in the climate, that humans are a primary cause in the increase of CO2 levels, and that the effects will bring harm. However, the scenarios of what could happen do not include Armageddon. There may be increases of famine do to drying conditions, loss of property due to rising water levels, etc. Humans will survive the climate change; we just won't be happy, and the costs of such warming could very well outweigh any costs in trying to prevent or weaken this fate.
So, what the hell is up with Rep. Michelle Bachman (R-Minnesota)?
That is some powerful stupid.
CO2 is natural from nature, etc. Yeah, so is radium. So are tornadoes. So are plagues. What an example of the naturalistic fallacy.
No study to show that CO2 is harmful. Um, the problem isn't that CO2 levels will get to high to be poisonous. That would be a problem with something like mercury. (If the levels of CO2 were high enough, there would be problems, but that isn't the case for what industrialization is being blames for.) CO2 levels on the rise lead to problems with the environment, which then affects us. And if you want to see that CO2 can be harmful in itself, why do you think plastic bags say "Keep away from infants"? Because they will suffocate!
CO2 makes up ~3% of the atmosphere. Rep. Bachmann, ever hear of Wikipedia? If you had, you would know that you are off by two orders of magnitude. Not a trivial error. If she was right, we would all be dead.
Humans have increases CO2 by only 3%. Try ~30%.
And what is the most probable source?
CO2 levels are well away from natural levels for the last ~million years. Human activity is the most likely source, and the effects are becoming known.
So, which this many pictures, I have to include one more, taken from Bad Astronomy.