What is all this talk about global warming? Two degrees? Five degrees? What’s the fuss? Is it real, or is it just a bunch of hokum dreamed up by some scientists to keep their grant money coming? We’ve just had a huge winter storm in the Midwest and its ten below zero outside. How can this be global warming! And even if we are warming, everyone I listen to says that we humans aren’t doing it – it’s some natural phenomenon like sun spots or volcanoes. What’s the big deal?
First, global warming and climate are not the same thing. Global warming is the increase in average overall temperature of the planet. Underscore the words “average” and “overall”. It’s not the cold winter temperatures people might be experiencing in New England on a given day in January. It’s the average temperature of the whole planet. Climate on the other hand is what gives us cold winters in one area, a rain forest in another and a dry desert in third. New England, Florida and Seattle all have different climates. Global warming can begin to shift those climates. For example, here in California it’s just been announced (Jan, 2014) that we are in the driest spell we’ve had in our entire history as a state. The state depends on the winter snow pack in the Sierra Mountains for much of its city and agricultural water. That’s down to 17% of what we usually have. Is California climate becoming more desert like? Is this one of the signs that climate change is coming?
So where is our present global warming coming from? Is it real? Are we causing it? To begin to understand this, let’s look at recent human history.
It’s so easy to forget, in our technologically rich modern world, how much simpler things were just 300-400 years ago. In the 1600’s, the only way to get anywhere was by walking or horseback, by wagon or horse-drawn carriage. A wooden sailing ship had no inboard motors; no radar, no GPS or radio; the captain had just a simple compass, a sextant, log entries and hand-drawn maps). Trains, cars and planes did not yet exist – no one had even dreamed of them yet. Electricity was a phenomenon of lightning storms, not power plants. Cooking was done over the fireplace and water was hauled by hand from a nearby well or stream. None of the conveniences we now take for granted existed.
Medical knowledge was primitive, so huge numbers of people, especially children, died each year from small pox, diphtheria, whooping cough, tuberculosis, and other diseases. This kept the overall population from growing at more than a snail’s pace.
Then over the next 300 years there was a big shift. In roughly the mid-1700’s, humankind invented the industrial revolution. Soon we learned to do more with iron than make swords, shoe a horse, or shape an iron plow. We discovered steam power, electricity and the light bulb, radio and the telegraph. Soon rails for the “iron horse” stretched from the Atlantic to the Pacific and all across England and Europe. It wasn’t until the mid-1800s that the first oil wells were drilled. Almost like magic the internal combustion engine appeared making possible the modern automobile and the early airplane. The development of contemporary science and engineering brought forth a rapidly accelerating list of inventions, while the Twentieth Century gave birth to modern medicine with its antibiotics, vaccines, modern surgical tools, and a vast (though not complete) knowledge of the human body and disease. If our ancestors from the 1600s could see us in our modern culture today they might think we had the power of the Gods.
Compared to our 17th century ancestors, our modern culture requires vast quantities of energy. Not only are we supporting 6,000,000,000 more people, but more and more of those billions are using modern forms of energy. Seventeenth century energy sources were pretty basic. Energy came from human effort, horses or mules, and wind or water power. Heat was from wood in the fireplace, and light came from whale oil lamps or candles. Today, however, we live in a world that requires unimaginable quantities of coal, oil, and natural gas to power our modern culture. And, except for keeping our gas tank full and paying the electric bill, we hardly notice.
When we multiply the energy hunger of our new technology by the huge fraction of the now billions of people able to afford that technology, then add the relatively recent harnessing of natural gas, oil and coal to produce that energy, we have a radically new situation never before seen on the planet.
These new fuels are very carbon rich. Burning that carbon produces lots of energy, but at the same time it also produces what is becoming a very dangerous byproduct: carbon dioxide, otherwise known as CO2. That CO2 goes straight into the atmosphere. How much? In 2007 alone, with our modern energy needs, it is estimated that we humans added to the atmosphere about 29,321,302,000 (that’s 29 billion!) metric tons (Wikipedia), or almost 60 trillion pounds of CO2. Let me emphasize: that’s for only one year! And a number so big (60,000,000,000,000) we can hardly wrap our heads around it!
Let’s be clear. The issue is not that carbon dioxide is dangerous to our health the way other pollutants like smog or lead or mercury are. It’s not. CO2 has been in the atmosphere for billions of years and we inhale a little of it with every breath. The danger lies in how this newly added CO2 interacts with heat and light.
Here are two key facts. First, CO2 is transparent to light coming from the sun but acts as a partial blanket to heat trying to escape the earth. Second, when light is absorbed by dark objects, the energy of that light gets converted to heat energy which tries to radiate out into space. If we add more CO2 to the atmosphere, it’s like wrapping the earth in a thicker blanket, making the overall average of the earth’s temperature go up. With the right amount of CO2 we have a planet with just the right average temperature and balance for life – too much CO2 and the planet warms up and gets out of balance. This can produce very serious problems, including big changes in the earth’s climate.
For an extreme example of what carbon dioxide can do, see Venus Greenhouse Effect by Fraser Cain. Here’s an edited excerpt: “The atmosphere of Venus is made up almost completely of carbon dioxide, with traces of nitrogen…. Scientists think that Venus used to be more similar to Earth, with lower temperatures and even liquid water on the surface of the planet. At some point, billions of years ago, the [CO2 increased and the] planet started to heat up. [Now, because of its dense blanket of CO2,] the average temperature on Venus is 864 degrees Fahrenheit.” This is hot enough to melt lead! (Remember, a hot day for us is 90 or 100 degrees Fahrenheit.)
So, you say: “What’s the big Deal? Two or three or even five degrees hotter isn’t going to bother me much. Why should I care?”
Well, warming like this causes climate change. So what is climate change and why is it so important? Read on.