Despite last month being a degree cooler than average for the entire 20th century (according to the official NOAA website) I still believe we ARE in a definite global warming period. One snowflake doesn’t make a winter and one cool April doesn’t make for a cooling trend.
Yes, I do accept the scientific consensus that average global temperatures have risen and the trend will continue for some decades into the future. I also believe that human burning of fossil fuels is partly responsible for this trend.
OK, I’ve said it, I BELIEVE IN GLOBAL WARMING.
Carbon Footprints Should be Reduced
We should each do what we can to reduce our carbon dioxide (CO2) emissions. My wife and I use an electric golf cart and bicycle for most local travel. For three years our only car has been a hybrid Prius (around 45-50 MPG). Our home thermostat is set to allow inside temperatures to rise to 78 degrees and fall to 64 degrees and our home is well insulated and so on and on.
I favor goverment policies that lead to a larger proportion of carbon-free power. This includes nuclear as well as wind, water, and solar energy.
Despite Joel’s “Corny Schemes” Topic, I believe biofuels are a partial solution to reducing CO2 levels. We need to recognize that corn-ethanol is our first serious foray into biofuels. Brazil has made much progress with sugar cane-based biofuel. Once the technology and US infrastructure are developed, we will transition from corn to switchgrass and agricultural, industrial, household, and sanitary wastes as the raw materials for biofuels.
I have long been in favor of a punitive “carbon tax” on all fossil fuels as a way to finance renewable power technology while encouraging more economical use of oil and coal. Senators McCain and Clinton are pandering to the public with their proposal to reduce federal gasoline taxes this summer. Senator Obama has it right (on this one issue :^) and Senator Kerry had it right many years before he ran for president when he suggested a 50-cent a gallon carbon tax.
This past month, as gasoline approached $4 a gallon, usage dropped a bit for the first time in a decade or more. The numbers of commuters car-pooling and using public transportation is increasing rapidly. Had we taken Senator Kerry’s (and my) advice ten years ago, and imposed a punitive carbon tax, we would now have much better public transportation and more energy-efficient and economical cars and houses and factories, and a much lower carbon footprint.
I wish there was public support for a carbon tax. Sadly, there is not. It is political suicide. However, since I am not running for office, I can give my opinion. I would start the tax immediately at a dollar per gallon and increase it a dollar each year until usage dropped by 25%. I would impose a carbon tax on all other carbon-based energy, including coal-fired electric power, in proportion to the carbon emissions levels. The best way to reduce our dependence on fossil fuel and increase carbon-free energy usage is via the pocketbook, not by government mandate and a “shell game” of trading of carbon credits.
Why We Should Limit Carbon-Based Fuels
There are three principal ways carbon exists on Earth (see figure at the head of this Topic):
a) AIR – As CO2 (carbon dioxide) and other atmospheric gasses including CH4 (methane).
b) SURFACE – In the carbohydrates and other molecules that make up living plants and animals.
c) UNDERGROUND – Sequestered as carbon and hydrocarbons in the form of coal and oil.
For millions of years, the UNDERGROUND carbon has remained pretty much undisturbed. It is a sequestered storehouse of energy absorbed by the Earth from the Sun over eons.
The AIR and SURFACE carbon is regularly exchanged between plants and animals. Plants absorb carbon-based gasses from the air and produce airborne oxygen for animals to breathe and food for animals to eat. The animals, in turn, return carbon-based gasses into the air and, when they defecate or die and decompose, return nutrients to the ground as fertilizer for plants.
The whole process is powered by energy from the Sun. Evaporation of surface water heated by sunlight lifts water vapor into the air and it later falls as rain and makes our rivers flow. Sunlight is also required for plant photosynthesis.
In recent times, particularly the past couple hundred years and especially in our lifetimes, this nice balance of Nature has been disturbed by the large-scale burning of UNDERGROUND carbon. The scale of this de-sequestration of carbon is without precedent.
The advantage of biofuels is that, while the sugar cane or corn or switchgrass is growing, those plants draw carbon out of the atmosphere, absorbing the present energy of the Sun to create fuel. While it is true that biofuels return the carbon they have absorbed back to the atmosphere when they are burned, they do not increase the total amount of free carbon. Burning of coal and oil, in contrast, adds old, formerly sequestered carbon to the atmosphere.
Do Al Gore’s Claims Have Scientific Merit?
One of the most dramatic moments in Al Gore’s An Inconvenient Truth movie is when he mounts a motorized platform and is lifted high on the stage to demonstrate how much he expects CO2 to increase in coming years. The sharp rise in CO2 (the upper red curve on his graph) resembles a “hockey stick” in shape. The implication he leaves in the minds of the audience is that the temperature (the lower blue curve on his graph) will experience a similar “hockey stick” increase in coming decades.
What is the scientific reasoning behind this implication? Well, according to the ice core data that provides a measure of the CO2 and temperature levels over the past 600,000 years or so, temperature and CO2 are related. When one goes up, the other tends to do the same. When one goes down, the other goes down as well. You can see the relationship in the portion shown in the above photo, going from 150,000 years ago to the present.
Gore’s argument is that increasing CO2 is associated with increasing surface temperatures. It is true that, as temperatures increase, the CO2 dissolved in the oceans tends to outgas (like warm soda that loses its fizz) and the additional CO2 in the atmosphere acts as a “greenhouse gas.” More CO2 in the atmosphere traps more of the infrared radiation from the Earth and that leads to further heating of the surface which leads to more CO2 coming out of the oceans, and so on and on. Surface heating melts the ice cap and causes the oceans to rise, flooding large areas on Earth now used for agriculture and human habitation.
Any additional CO2 due to human burning of fossil fuels will add to the process, and, Gore concludes, lead to a “tipping point” within the coming decades. Once we go over that tipping point, large portions of the Earth will become uninhabitable and that will be a disaster for all mankind.
I agree with much of the above argument, but I do NOT believe there is any scientific evidence – certainly NOT from the ice core record – that human activity is the principal cause of the global warming observed so far, nor that we are headed for any tipping point.
What Humans are Responsible for and What We Can Do
Even if humans were the principal cause of global warming, no matter what we do (short of killing half the world population in a nuclear war or genetic engineering disaster) there is no way we will reduce CO2 worldwide in the coming decades. With China, India, Russia, and other countries rapidly increasing their standards of living as they adopt something like capitalism, they will inevitably burn more fossil fuels and emit more CO2. All we can do is slow the rate of increase in atmospheric CO2.
Despite Al Gore’s movie, there is no scientific evidence that we are approaching anything like a “tipping point” anytime soon. Despite his emotional claims that rising CO2 levels will cause global temperatures to shoot up at what he calls a “hockey stick” curve, the very ice core data he used to make his point demonstrates the very opposite.
I’ve taken the same ice core data Gore used and expanded the portion from about 150,000 years to the present.
Look at the last strong warming period that hit its peak about 130,000 years ago. Notice that it was the temperature (orange curve) that started to rise and the CO2 (blue curve) followed about 600 to 1000 years later. If you look at the other periods of rising temperature, you will also see that the temperature rises before the CO2 in every case. Thus, the ice core data provides absolutely no evidence that rising CO2 causes temperatures to rise. It is clear the causality is in the exact opposite direction. Rising temperatures, due to some other cause, namely the distribution of Solar energy on the Earth, is what causes CO2 to rise.
In fact, look at the period after the peak warming at about 130,000 years ago and you will see a rapid drop in temperature over a 10,000 year period while the CO2 remains high! If high levels of CO2 are the primary cause of global warming, how on Earth could the temperatures drop consistently for 10,000 years while CO2 remained high?
The most recent warming period started about 25,000 years ago and, for about 15,000 years continued to climb. CO2, as expected, followed suit. However, about 10,000 years ago, temperatures stabilized, while CO2 continued to rise rapidly!
Humans did not burn a significant amount of fossil fuel until the industrial revolution, a few hundred years ago. Therefore the CO2 rise must have been due to some other factors.
Thus, the ice core data displayed by Gore and other global warming alarmists gives no scientific support to the idea that human activities are a principal cause of the current warming trend. All the historic ice core data shows the opposite, namely:
1) Temperature rises BEFORE CO2 rises. Therefore the causality is in the opposite direction (temperature change causes CO2 change), or both are caused by something else.
2) Temperature fell rapidly while CO2 remained high for 10,000 years, so high CO2 does not cause temperature to rise. You could make the opposite claim that high CO2 caused the temperature to fall!
3) Fast rising CO2 does not cause temperature to rise in proportion, if at all. In fact, all the periods of rapid temperature drop on the above graph are during times of steady or increasing CO2 levels!
It’s the SUN, Stupid!
Energy radiation from the Sun varies on several cycles, the best known of which is called the "Sun spot cycle" and happens every eleven years. There are longer cycles of variability that extend to centuries and millennia.
According to U Montana there are three major cyclic components that affect the Earth's orbit around the Sun: (1) Eccentricity of ~100,000 years, (2) Axial Tilt of ~41,000 years, and (3) Precession (or "wobble") of ~23,000 years.
These components do not affect the total amount of solar radiation reaching the Earth, but rather energy distribution between the polar and equatorial areas and seasonality. That, in turn, affects the build up and melting of polar ice. Based on the ice core data, the combination of these cycles triggers cooling and warming periods.
Therefore, when the orbital and solar radiation cycles happen to coincide, which may occur around every 100,000 years, a global warming cycle is initiated. The warming causes more CO2 to be driven out of the oceans and, over an 800 year period, CO2 levels rise and stay high until the solar radiation high point passes. At that point, cooling begins and, a thousand years or more later, CO2 levels decrease as more of the CO2 gas is again absorbed into the cooler oceans.
We are definitely in a global warming period.
Human activity, namely burning coal and oil that have been sequestered underground for eons is definitely responsible for a portion of this global warming.
Therefore, to the extent practical, we humans should reduce our dependence on carbon-based fuels. However, no matter what we do, human-caused CO2 emissions will continue to rise in the coming decades. We may be able to slow the rise, but there is no practical way to stop it that will be acceptable to the forces at work in human civilization.
The global warming period we are in is mainly due to natural, uncontrollable variation in our Earth’s orbit around the Sun: orbital eccentricity, axial tilt, and wobble.
BOTTOM LINE: Get used to it! We are going to have to use technology to cope with steadily rising temperatures and sea levels for the coming decades. It will be bad, but nothing near what the alarmists are predicting. There may be an average increase of a degree and a foot or so over the coming fifty years. Many low-lying agricultural lands and cities will be flooded. Some sea walls and levees will prove to be inadequate and will be washed away or have to be torn down. Human habitation and permanent buildings will be banned on most land below high water level. Building codes will restrict new construction in low-lying areas to protect life and property. Life will go on!