Global Climate Change: Is it Human Caused?
Why is there such a debate over whether humans are causing global climate change?
Why can’t we tell?
The answer has two parts, a scientific part and a political part.
Scientifically, weather is very, very complex.
Earth’s atmosphere is very thin, though to us it seems deep, and the system of weather as we know it is very fragile, though winds and storms seem powerful to us. A very good analogy is the skin of a soap bubble.
If we look at a soap bubble we’ll see swirling colors which are always in motion. The forces that keep the colors swirling on the soap bubble are very much like those that create our weather, swirling and constantly moving. It is moved around by very subtle forces, the difference between warm and cool areas and minor differences in constituents. They are complex processes, though. Just as it is easy to understand what makes the colors on a bubble swirl, it is almost impossible to accurately predict where colors will form, or for how long.
Photo by Karl E. Deckart; From: Commons
That’s the difficulty with understanding the nature of human caused climate change. We have a fairly good idea of what makes the colors of our weather swirl, but not a good way to predict what the changes will be. They are "complex", meaning as one thing changes, other things change unpredictably.
The by-products of industrial activities are "greenhouse gases", primarily carbon dioxide and methane. The biggest source is carbon dioxide from burning hydrocarbons. These gases collect in the atmosphere and cause changes in the way our planet absorbs and releases heat. A great example of the greenhouse effect is Venus, which is hotter than Mercury though it is much farther from the sun. Humans didn’t make greenhouse gases on Venus, but the effects are the same.
On Earth, volcanoes produce more carbon dioxide than humans, and swamps produce more free methane, too. So shall we blame volcanoes and swamps? Since we can hardly pass laws against volcanoes and swamps, we’ll have to control the other major producer of greenhouses gases, humans.
Indeed, most independent climatologists (scientists who study climate) are in agreement that human activities are changing the Earth’s climate. It is difficult to tell exactly what changes will occur, but there is agreement that we are speeding up patterns in the climate.
Which brings us to the political reasons for confusion on climate change.
Who are the players, why would they lie?
It will be difficult for all of us to curb greenhouse gas emissions, but it will most hurt the largest purveyor of hydrocarbons, the oil industry. They stand to lose the most if we stop making carbon dioxide. As a result, the oil industry and those who have invested in the oil industry don’t want global climate change to be a true thing. They pump a lot of money into organizations like the "Heartland Institute" which then finds scientists to disagree about human contributions to global climate change. Indeed the Heartland Institute, funded by Exxon and others, is the primary source of "it isn’t your SUV" style anti-climate change rhetoric. They often produce confusing charts and graphs showing what we already knew: Earth’s weather changes all the time, in response to CO2 and other things.
The other thing they do to confuse the issue is insist on the name "global warming". This is for two reasons; first it is easier to dispute global "warming" than global climate change. The second, most people wouldn’t mind if it were a little warmer. Since the near distant prediction of global "warming" is only 3 degrees, most people feel like that isn’t a big deal.
But the issue isn’t simply warming, it’s the amount of energy in the system, which is harder to understand. The colors on the soap bubble of Earth will swirl more violently, and weather and ocean current subsystems (ocean currents are an important component of the weather system) that have been stable, like the Humboldt Current, will likely change. The swirls of color that they represent will move.
On the other side we have scientists working for governments and intergovernmental agencies. What do they have to gain by finding human caused climate change? They have the same reason as scientists working for Heartland: funding. If the scientists at Heartland found SUVs were responsible for climate change, they wouldn’t be funded again. It is also very possible that scientists working for intergovernmental agencies would lose their jobs if there were no human caused global climate change. They might be motivated to find humans the cause.
None-the-less, by far more scientists accept human contributions to impending global climate change, as do most world leaders, and even Governator Arnold Schwarzenegger.
Just because the leading scientists agree that humans are contributing to global climate change doesn’t mean they’re right; leading scientists disagreed with the theory of evolution when it was introduced, but no serious scientist doubts it now.
How can we decide for our selves?
A recent poll shows that if you are younger than 34 years old, you likely understand that humans cause climate change. If you have some college education, you are more likely to accept that humans cause change. Still, the margins aren’t very large; most people simply don’t know what to believe. We don’t want to ruin the weather, but we don’t want to feel guilty for driving a bigger 4 wheel drive, which we actually need.
I think we can look at it like this:
If I’m honest with myself, I’ll admit that burning every year 207,000,000,000 gallons of oil and 1, 000, 000, 000 tons of coal, not to mention natural gas and tons of wood, has to have some effect on the weather. A lot of what we burn ends up in the air, year after year how can it not change something?
The globe has periods of relatively stable weather, and periods of sudden climate change. It isn’t just "do we cause it" but rather "what effect will we have". This means that, if the Earth is going through a natural climate change, AND we continue to add greenhouse gases, we will bring about changes in the climate more quickly. Because the system is complex, and not just "complicated," we don’t know what will happen. Some climatologists worry it will actually result in a rather sudden ice age. If the ocean currents change as a result of more energy in the system, some places could get colder or drier very quickly.
Let’s not lose sight of what’s at stake: we aren’t worried because we want to "save the Earth". The Earth will be just fine, it’s ourselves we’re worried about.
Out here we need our SUVs and our old tractors and trucks. We love cows and beef and can’t believe what we eat heats the Earth. How do our needs change how we might feel about global climate change?
Do scientists agree on human caused global climate change?
SCIdev.net
New Scientist:
The government site and it’s education partner, Global Change Research Information Office, which has a very nice description.
What the EPA thinks.
What NASA thinks.
Play with Global Climate Change yourself.
Columbia.edu report on Human Caused Climate Change
The Heartland Institute is funded by oil companies and they want you to know that Global Warming is a bunch of B.S. They fostered the Nongovernmental International Panel on Climate Change (NIPCC) which was created specifically to counter the Intergovernmental Panel on Climate Change, (IPCC), a joint effort of the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP). To be clear, the NIPCC is created by Heartland to disagree with convential science, and the IPCC is a panel created to examine current research on the causes and implications of climate change. If you are confused between NIPCC and IPCC, the NIPCC is glad.