NATURAL PERSPECTIVES:

Two weeks ago, the Independent ran a shocking article in which our elected representative to the U.S. Congress, Dana Rohrabacher, claimed that it is a myth that humans are causing global warming (“Rohrabacher cold to global warming,” Aug. 10).

He claimed that termites in the rain forest are more responsible for global warming than humans, and that we should bulldoze the rain forest if we’re concerned about it.

This denial of reality is appalling, but at least it represents progress. Congressman Rohrabacher has at least now acknowledged that global warming is occurring. Just a few years ago, global warming itself was considered a myth by nay-sayers. Now, they’ve adjusted their story to claim that the “myth” is that global warming is caused by people.

I (Vic) wanted to get the story straight from the horse’s mouth, so I called Rohrabacher. Rohrabacher bases his conclusions on the fact that greenhouse gas production by humans is small compared to that produced by natural sources. His impression was that human sources are only a small percent of the total.

Unfortunately, the contributions of human activity are not that small. Natural production of carbon dioxide, the No. 1 greenhouse gas, by living things is about 60 gigatons per year, while burning fossil fuels produces about 6.1 gigatons. That means humans are responsible for producing 10% of the carbon dioxide that goes into the atmosphere.

While seemingly small, that 10% is powerful because it throws off a natural balance. Natural production of C02 happens to be nicely balanced by natural consumption. Carbon dioxide is produced biologically every day by living things when they respire, but it is also taken in every day by plants when they photosynthesize.

In nature, these two factors balance one another out.

The CO2 that is emitted from cars, trucks and smokestacks is not balanced by anything, so it adds to the atmosphere day after day after day. Think of the difference between gross and net. Human sources of CO2 may be a small part of the gross production, but they account for ALL of the net production of CO2.

We have very precise measurements that document that CO2 in the atmosphere is increasing dramatically. Can this increase be the result of volcanoes, another source mentioned by the congressman when I spoke with him?

No. Volcanoes produce less than a gigaton of CO2 each year. They are small producers compared with humans.

Over the last 400,000 years, atmospheric CO2 levels have fluctuated between 180 and 300 parts per million. But since the industrial revolution 150 years ago, CO2 levels have climbed steadily. They’re now at 380 ppm, the highest level that has ever been observed, and are still rising.

There is no natural source that can account for this sudden increase.

How about the other major greenhouse gases? Here, the congressman’s position is even weaker. The second most important greenhouse gas is methane. Methane is added to the atmosphere primarily by humans.

The U.S. Environmental Protection Agency estimates that 60% of all releases of methane to the atmosphere come from human-related sources. All natural sources combined add up to only 40%.

There are still some scientific unknowns in the story of global warming, but the cause of rising greenhouse gases is not one of them. That cause is clearly us.

What can we do about it? That, unfortunately, is a very tough question. Cutting back on the burning of fossil fuels is the most obvious answer. But all major nations on earth, rich and poor alike, are now so dependent on coal, petroleum and natural gas that rapid reduction of its use is just not something we can realistically hope for.

In his movie “An Inconvenient Truth,” Al Gore suggested that society do several things, all of which would be necessary to solve the problem. Cutting back on fossil fuel consumption was not the big one. The big one was CO2 entrapment, or, to use the big word that experts use: sequestration.

It is technologically possible to build equipment that can sequester, or entrap, the CO2 that comes out of the smokestacks of factories and power plants.

The new technology will undoubtedly create a whole new industry in its own right, creating jobs and stimulating the economy.

Some people are probably daunted by what they see as an impossibly great challenge. Well, when you take things piece by piece, remarkable things can be achieved.

For example, look at the amount of methane gas produced by America’s landfills. Landfills produce methane from all that garbage rotting away down beneath the surface.

But landfills across the country have recently installed new technology to trap that methane and keep it out of the atmosphere. As a result, methane escaping from landfills has declined by nearly 25% since 1990.

It is clear that Rohrabacher’s views on global warming are the dominant views right now in Washington, D.C. We won’t be able to count on the White House or Congress to lead us toward the new technologies that society is going to need.

Thank goodness Gov. Arnold Schwarzenegger is approaching this problem with his eyes on the long term. His initiatives to head off global warming will not satisfy everyone, but they are certainly a step in the right direction.

Let’s hope that California can get in on the ground floor of the CO2 trapping industry and get started solving this human-caused problem.