One, Two Three, that’s how easy - it’s gonna be.
We are often told that our earth, our atmosphere, and our climate are just too, too complicated. There is no way we can really figure out if global warming is happening so it is best not to do anything right now – until we are sure.
Nonsense, says Astrophysicist Jeffrey Bennett. “it’s as easy as 1,2,3.”
1. Fact: Carbon dioxide in our atmosphere traps heat and keeps our planet warm.
The universe is a cold, icy cold place. Much of it is close to absolute zero which is about -460 degrees F. Why then, is our planet holding at such a nice life-sustaining temperature?
Most of our abundant sunlight is reflected right back into space, but, happily, some is held in our atmosphere – which behaves like a big blanket. How does that work?
A guy by the name of John Tyndall, in 1859, figured it out. He bombarded the gases in the air with Infrared light (reflected sunlight) and found that the main components of air, oxygen, and nitrogen, do not hold heat.
However, two gasses that occurred in only tiny amounts, did. Carbon dioxide and water. These minor gasses hold onto enough heat to keep life comfortable. He labeled these “greenhouse gases” because they work like windows of a greenhouse to keep warmth in.
Today, while other greenhouse gases have been identified, carbon dioxide remains the most important of these heat holding gasses. No one argues with this.
Without tiny amounts of this gas in the atmosphere, life as we know it would not be possible, so let’s have a little gratitude.
2. Fact: Since the beginning of the Industrial Revolution, humans have been emitting increasing amounts of carbon dioxide into our atmosphere – more than natural global processes can remove. It has been building up.
For 180,000 years prior to the industrial revolution, carbon dioxide levels in the atmosphere varied between 180 and 300 parts per million. For the 40,000 years immediately prior, the level held fairly steady at about 280 ppm.
In 2012, the concentration of CO2 in the atmosphere was first measured at 400 ppm and it is increasing.
This fact is also not controversial. It is well supported by data.
3. Fact: Carbon dioxide is doing what carbon dioxide does. It is holding on to heat. Because there is more CO2 in the atmosphere, there is more retained heat.
Our planet is warming.
Here again, Dr. Bennet points out, there is no argument. Overall global temperatures measured countless times in oceans, on land, by satellites, at the poles, at the equator demonstrate indisputably that temperatures are increasing.
This heat is not evenly distributed. Some places have become a lot warmer while a few have actually cooled.
But, if that is true, why is there controversy about global warming?
Any controversy among scientists is not about whether global warming is occurring. The basic science is clear. What is not so easy is to predict the severity and timing of the effects, exactly where they will occur, long-range consequences, and ways to mitigate, or at least survive, the changes in climate we are already seeing.
“The vast majority of scientists who have studied the issue have concluded that it is a serious threat to our future that therefore demands serious and immediate action,” according to Dr. Bennett.
A minority of scientists, often estimated at around 3%, disagree and feel the threat does not justify action at this time.
But is global warming occurring and disrupting our climate? Easy peasy.