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CO2 is Latest Environmental Challenge

pollution from various sources is causing environmental concern and global warming

We've come a long way in our struggle to reduce pollution. Today's vehicles are the cleanest ever, and getting cleaner all the time. Advances in emission control technology has cut hydrocarbon (HC) and carbon monoxide (CO) emissions to almost nothing. Oxides of nitrogen (NOX) emissions, which also contribute to smog, have also been reduced to a fraction of what they once were. Evaporative emissions from the fuel system have also been eliminated, and gasoline has been reformulated to burn cleaner and reduce emissions even more. Consequently, today's cars are probably 99% cleaner than their pre-emission counterparts of 30 years ago.

As the next level of emission standards are phased in for cars, light trucks and heavy trucks, emissions will further drop. Reduced sulfur content in fuels and "Tier II" emission regulations should lower vehicle emissions another 20 to 25%.

Today's emission controls have done an amazing job of minimizing pollution from motor vehicles. But one thing emission control technology has not been able to change is the basic chemistry of combustion itself. The issue now is CO2 (carbon dioxide).

Almost all motor vehicles today burn some kind of "hydrocarbon" fuel be it gasoline, diesel fuel, propane or alcohol. A hydrocarbon is any substance that contains hydrogen and carbon. This includes crude oil, gasoline, diesel fuel, natural gas, coal, wood and even you and me. In other words, hydrocarbons are the chemical building blocks of all living matter past and present. The crude oil we pump from underground today came from ancient peat bogs and forests from millions of years ago -- or so the theory goes.


When anything that contains hydrocarbons is burned, the bonds that bind the hydrogen and carbon atoms together are broken. This releases heat energy, which can then be put to use to power a motor, heat a boiler, cook a meal or whatever. Burning also causes the hydrogen and carbon atoms to combine with oxygen in the air forming water vapor (H20) and carbon dioxide (CO2). That's the basic chemistry of all combustion.

Water vapor is no problem because two-thirds of the Earth's surface is covered with it. So what's a little more? The problem is carbon dioxide. CO2 is a colorless, odorless, nontoxic, harmless gas. Human beings and animals exhale carbon dioxide with every breath they take. Add to this all the CO2 that's being produced by every motor vehicle that's being driven, by every furnace that's burning some type of fuel, by every flame that's burning anywhere in the entire world and it adds up to zillions of tons of CO2.

Were it not for plants, we all would have suffocated in our own CO2 a long time ago. Fortunately, plants have the ability to absorb CO2 from the atmosphere and convert it back into organic carbon compounds (hydrocarbons) that become part of the plant. The process requires sunlight and is called "photosynthesis." At the same time, plants release oxygen back into the atmosphere, which we can then use to breathe and burn up more hydrocarbons.

Back to CO2. Historically, the amount of naturally occurring CO2 in the atmosphere has been 290 parts per million (only 0.0003%). Air is mostly nitrogen (78%) and oxygen (21%). CO2 is not a pollutant in the traditional sense, but it does retain heat in the Earth's atmosphere. That's why scientists refer to CO2 as a "greenhouse gas." It traps and holds heat just like the glass in a greenhouse.

Based on analysis of air bubbles trapped in ice cores taken at the north and south poles, scientists say the level of CO2 has been gradually rising since the dawn of the Industrial Revolution in the 1700s. When people started burning wood and coal to fuel industrial steam engines and heat their homes, CO2 levels started to rise and have been going up ever since. And since World War II, the rate of increase has been accelerating at an ever quickening pace. The latest count puts CO2 at over 360 parts per million (about a 25% increase).

As CO2 levels continue to rise, scientists fear it will cause a gradual warming of the Earth's average temperature -- which they say has already gone up almost a couple of degrees based on historical data. This, they say, has the potential to upset ocean currents, global weather patterns and rainfall -- which may have far reaching and negative consequences for agriculture, fishing and life in general. Some fear it may even lead to a melting of the polar ice caps causing the oceans to rise and flood coastal areas.

In Al Gore's documentary, "An Inconvenient Truth", he quotes a lot of scary statistics about what's happening with the earth's climate as a result of rising levels of CO2 in the atmosphere. I would highly recommend seeing this movie, whether you think rising levels of CO2 in the atmosphere is causing climate change or not.


Concerns over such dire predictions lead to a world summit meeting in Kyoto, Japan in December, 1997. The outcome of this meeting was a proclamation calling for significant reductions in CO2 emissions by industrialized nations as well as developing nations. The Kyoto Protocol, as it was called, has yet to be finalized. Though many others nations have signed it (including most of the Europeans), the U.S. has balked at signing it because it would call for drastic changes in the American lifestyle.

To reduce our CO2 emissions, we would have to drive smaller, more fuel efficient cars, raise the fuel economy requirements for trucks, and adopt a variety of conservation measures to reduce energy consumption. Given the current political climate and economic slowdown, it seems highly unlikely the Bush administration will ever sign the Kyoto Protocol.


If cars and trucks put carbon into the atmosphere and trees remove it, how many trees does it take to offset the carbon released by one sport utility vehicle?

The following calculations may be subject to debate, but here are my ballpark guesstimates:

One gallon of gasoline weighs about 8 lbs. Of that, about 7 lbs. is carbon (the rest is hydrogen).

If a SUV that gets 15 mpg is driven 15,000 miles a year, it will burn 1,000 gallons of gas. That puts about 7,000 lbs. of carbon into the atmosphere (combined with oxygen as CO2).

A mature tree 40 to 50 feet high weighs around 10,000 lbs. Of that, at least 7,000 lbs. is organic carbon compounds (the exact amount will vary depending on the species and the density of the wood). To reach this size, most trees need 30 to 40 years of growing time. This too will vary depending on the species of tree, its geographical location, soil conditions and weather. Trees in hot, wet tropical climates grow a lot faster than trees in northern climates.

Assuming these estimates are reasonably accurate, one mature tree contains about as much carbon as the 1,000 gallons of gasoline burned by a typical SUV in a year.

Tree drivethru

But remember it takes 30 to 40 years for the tree to absorb all that carbon from the atmosphere. The process of "photosynthesis" takes time. Leaves use sunlight and water to convert CO2 from the atmosphere into sugar that the tree uses to grow and build more wood fiber. The tree's average carbon uptake, therefore, may only be about 200 lbs. of carbon a year.

To offset the carbon released by driving a SUV 15,000 miles a year, therefore, it takes at least 35 medium-sized healthy trees to convert CO2 into wood.

What happens to the carbon once it's been taken out of the atmosphere by the trees and bound up in the wood? It stays there until something happens to the tree.

If a tree dies of old age or is blown down in a storm, the wood eventually rots. Some of the carbon is slowly released back into the atmosphere as CO2 while the wood rots, but this may take several years. Much of the carbon remains in the soil as organic nutrient for other plants, worms and insects.

If the tree is cut down and made into lumber, the carbon also stays bound up in the lumber until something happens to whatever the lumber was used to build.

But if the tree is destroyed in a forest fire, is burned to clear land or is cut for firewood, all of the carbon that's been stored in the tree since it was a sapling is immediately released back into the atmosphere as CO2. Consequently, burning a tree is the carbon equivalent of driving a gas-guzzling SUV 15,000 miles a year.

Here's another fact to ponder. Every time a farmer in a Third World country clears and burns an acre of heavily wooded forest to grow sweet potatoes or graze cattle (a practice called "slash and burn" agriculture), he releases as much carbon into the atmosphere as 400 SUVs do in a year! And many of these farmers will slash and burn 20 to 50 acres a year.

In Brazil alone, nearly 3 million acres of rain forest are being slashed and burned into oblivion every year. Multiply these acres times the amount of carbon that's being put back into the atmosphere and it far outweighs the CO2 that's being released by the entire U.S vehicle fleet!

The point here is that no matter what we do to minimize pollution or improve fuel economy will make much difference in restoring the atmospheric carbon balance if deforestation continues to run rampant in other parts of the world. The losses there will more than offset any gains we might be able to achieve here.

the world's forests are in serious decline
What's really sad about all of this is that forest land cleared by slash and burn agriculture is only productive for a few years because the soil is thin and poor. It soon becomes rock hard forcing the farmers to clear even more land. To make matters worse, the cleared land doesn't come back. The trees are gone forever along with their ability to absorb carbon from the atmosphere. And without the trees, there's not much hope of restoring a natural atmospheric carbon balance.


We now have more motor vehicles than we do licensed drivers in this country (210 million). The worldwide vehicle fleet is estimated to be about 430 million cars and trucks (up from 50 million in 1950), and will surpass 650 million within the next 8 to 10 years! Most of this growth is occurring in developing nations that do not have the strict emission requirements that we do. ANd even if they do adopt the same emission standards as Europe, Japan and the U.S., all of these vehicles will still produce millions of tons of CO2 as a byproduct of burning gasoline and diesel fuel.

With fewer trees left to absorb carbon and more vehicles producing carbon, don't expect the atmosphere's carbon balance to improve any time soon. The scales have probably tipped irreversibly toward higher and higher levels of CO2 for the foreseeable future.

The biggest unknown is what effect all of this will eventually have on all of us. Nobody argues with the fact that the amount of CO2 in the atmosphere is steadily rising because of human activity. What we don't know is what the long term consequences of a CO2 imbalance will be or how it will actually affect our daily lives. Waiting to find out may prove costly if we miss the window of opportunity to make significant changes now.

Many environmentalists say one step we can take now to reduce CO2 emissions is to improve the fuel economy of all classes of vehicles. U.S. fuel economy standards have nearly doubled since the energy crisis days of 1973 -- but have remained relatively flat at 27.5 mpg for passenger cars for the last 15 years. For trucks, the average fuel economy is only about 20 mpg. Yet because of the increased popularity of trucks and SUVs in recent years, the average fuel economy of all new vehicles in the U.S. has sunk to the lowest level since 1980!

According to the Sierra Club, every day America consumes 18 million barrels of oil. Not all of that is for transportation, but in a year's time we burn up about 120 billion gallons of gasoline.

If the Corporate Average Fuel Economy (CAFE) standards for trucks were raised to match that of cars (27.5 mpg), it could save one million barrels of oil per day. That's a lot of carbon! Raising the CAFE standards for cars to 45 mpg and light trucks to 34 mpg would increase the savings to three million barrels of oil per day.

Rising fuel prices rather than Congressional action (or inaction as the case may be) will likely provide the strongest incentive to get motorists to buy more fuel-efficient vehicles and reduce their driving. But it's hard to cut back on the number of miles driven (we drive over two trillion miles a year now) because our cities and suburbs are sprawled out across the land. Most people are totally dependent on a motor vehicle to get to work, school, to shop and do everything else in life (thankfully for those of us in the parts and service business). Mass transit doesn't work outside the central cities because things are too spread out. And in rural America, a car or a truck is the only way to get to town or any place else.


One solution that can allow us to keep our big SUVs and get good fuel economy too is "hybrid-electric" technology. With this approach, a small displacement, fuel-efficient gasoline or diesel engine is used in conjunction with an electric motor and battery to power the vehicle. The regular motor is used for highway driving and to charge the battery. The rest of the time the vehicle runs on electric power or a combination of battery and gasoline.

Depending on how the control strategy is set up, a hybrid-electric may deliver double the fuel economy of a conventional vehicle in normal driving, and even triple the usual mileage in urban stop-and-go driving. Instead of wasting fuel at a stop light, a hybrid-electric shuts the engine off when the vehicle stops. The engine remains off until the light changes and the vehicle accelerates on battery power up to a certain speed.

As promising as this new technology is, there are currently only two vehicle manufacturers producing hybrid-electric vehicles: Toyota and Honda. The Toyota Prius is a compact four-door car that has an EPA rating of 52 mpg in the city and 45 mpg on the highway. But production is limited and the waiting list is reportedly six to eight months if you can get one. Dealers are also getting full list price plus as much more as the market will bear.

Ford says it will have a hybrid-electric version of its Escape SUV on sale in 2003. This will be followed by a hybrid-electric version of the six-cylinder Explorer in another year or two. But like the Prius, both will be produced in limited numbers and will be in short supply. Buyers will also pay a premium for the fuel-saving technology. So unless there is a large scale shift to mass produced hybrid-electric vehicles over the next three to six years, we won't see any significant improvement in CAFE numbers for a long time to come.

Electric vehicles are still on the fringe and will probably stay there because of lagging battery technology. Electric vehicles that emit no pollutants and no CO2 certainly make sense in polluted urban environments. They're the ultimate energy-efficient vehicle for stop-and-go driving because they waste no energy when they're stopped in traffic. But nobody has yet come up with a cheap, lightweight, safe, quickly rechargeable battery. And even if they did, it would take years for the new technology to go into mass production and for the public to accept it.

There's also the issue of whether or not electric vehicles would actually reduce pollution. The electricity needed to recharge the battery has to come from another power source. Unless that power source is nuclear, hydroelectric, wind, solar or geothermal, there is little or no net reduction in pollution or CO2 because most electrical power in this country is generated by burning coal or natural gas. No new nuclear power plants have been built in the U.S. for over 25 years, and many nukes are now reaching retirement age and will have to be decommissioned. Unless there is a rebirth of nuclear energy or a large scale shift to alternative sources of clean power (which are more expensive and require huge financial investments), electric vehicles aren't going far.

Even with an advanced battery breakthrough, some question whether the existing power infrastructure has enough capacity to supply the needs of an expanding fleet of electrical vehicles. Several years ago, California suffered rolling blackouts which were supposedly due to an energy shortage. The shortage turned out to be a hoax perpetrated by the electric companies to drive up their prices and profits. Today, some experts say the U.S. has enough excess electric generating capacity to power up to 80% of all the vehicles on the road if they were electric or electric-hybrid vehicles. The oil companies obviously wouldn't like that to happen, and are doing everything they can to downplay the potential of electric vehicles. Anyone who thinks otherwise should watch the documentary Who Killed The Electric Car?


Hydrogen Fuel cells currently hold the greatest promise for solving our environmental concerns over pollution and CO2. A fuel cell produces electricity by combining hydrogen and oxygen. The only byproduct is water vapor -- provided the fuel source is pure hydrogen.

Hydrogen is one of the most abundant elements on Earth. It can be made from natural gas, oil or even coal, or by using electricity to break down water into hydrogen and oxygen. Even so, it is expensive to produce and contains much less energy per liter than other hydrocarbon fuels.

Hydrogen is also a hard-to-store fuel. Because hydrogen is a gas, it has to be compressed at extremely high pressure (3,000 to 4,800 psi). This requires large, heavy, expensive fuel tanks that reduce a vehicle's driving range and fuel economy. It can be liquefied to increase its storage density, but this requires special insulated cryogenic storage tanks to keep the fuel at -253 degrees C. Another storage method is to use "metal hydrides" or activated carbon that absorb hydrogen like a sponge. But these approaches are also bulky, heavy and expensive. What's more there is no distribution system for hydrogen like there is for gasoline, diesel fuel or even natural gas. So even if you had a hydrogen powered vehicle today, you would have a very difficult time finding a place to fill it up.

One solution for storing hydrogen is to not store it as a gas but to extract it from another fuel such as gasoline or methanol alcohol. A device known as a "reformer" can break down these fuels to release the hydrogen. But adding a reformer adds cost and complexity, and also reduces its fuel efficiency. A reformer also does nothing to reduce our dependence on oil. Even so, Chrysler, Mercedes. BMW and several other vehicle manufacturers have all demonstrated prototype fuel cell powered vehicles that use reformers to extract hydrogen from gasoline or methanol.

Why not just burn hydrogen in an internal combustion engine and forget the high tech fuel cell and reformer? You can, but compared to other fuels hydrogen is a lousy motor fuel. It has a very low octane number, which means it causes detonation and preignition unless the compression ratio is cut way down. It also tends to backfire through the intake manifold. And it doesn't get very good fuel mileage, either. A gallon of liquefied hydrogen has only about one fourth the energy content of a gallon of gasoline.

Time will tell which technologies will eventually help us meet our environmental challenges. It's not just motor vehicles that bear the brunt of reducing pollution and CO2 emissions. It's all forms of energy consumption and power generation worldwide as well as the issue of deforestation. Hopefully, we can come up with solutions that satisfy everybody's concerns and needs while there is still time.

Update: Burning Palm Oil No Solution Either

In recent years, some power generating plants in Europe have been using palm oil as a substitute for petroleum because palm oil is a renewable biofuel that is carbon neutral, and it is relatively cheap. But a new report issued in late 2006 by Wetlands International, Delft Hydraulics and the Alterra Research Center of Wageningen University in Holland found that burning palm oil isn't such a great idea after all. The study measured the carbon released from peat swamps in Indonesia and Malaysia that had been drained and burned to plant palm oil trees. About 85 percent of the world's palm oil comes from the two countries, and about one-quarter of Indonesia's plantations are on drained peat bogs.

The four-year study found that 600 million tons of carbon dioxide seep into the air each year from the drained swamps. Another 1.4 billion tons go up in smoke from fires lit to clear rain forest for plantations, smoke that often shrouds Singapore and Malaysia in an impenetrable haze for weeks at a time.

Together, those 2 billion tons of CO2 account for 8 percent of the world's fossil fuel emissions, the report said. Draining the peat swamps to grow palm trees has had a very negative impact. Not only has it increased carbon emissions significantly, but it has also destroyed wetland ecosystem that can take carbon out of the atmosphere.

Update: November 29, 2007:

New Report Says U.S. Can Reduce Greenhouse Gas Emissions Significantly Wihtout Significant Pain

A new report called Reducing US Greenhouse Gas Emissions: How Much at What Cost? published jointly by McKinsey & Company (a management consulting firm) and The Conference Board (a business research organization) says the United States could reduce projected 2030 emissions of greenhouse gases by one-third to one-half at manageable costs to the economy and without requiring big changes in consumer lifestyles.

The report is based on detailed analysis of 250 opportunities for reducing emissions of carbon dioxide and other gases thought to contribute to global warming.

If no changes are made, annual U.S. greenhouse gas emissions will increase by 35 percent to reach 9.7 gigatons of carbon dioxide equivalent (CO2) in 2030, according to an analysis of government forecasts. At this level, emissions would overshoot by 3.5 to 5.2 gigatons the targets implied by economy-wide climate change bills introduced in Congress. A gigaton is one billion metric tons.

The report shows a reduction of 3.0 to 4.5 gigatons in 2030 is achievable at manageable cost using proven and emerging high-potential technologies, but only if the U.S. pursues a wide array of options and moves quickly to capture gains from energy efficiency.

Almost 40 percent of the greenhouse gas emission reductions identified come from options that more than pay for themselves over their lifetimes, thereby creating net savings for the economy. For example, improving energy efficiency in buildings, appliances and industry could yield net savings while offsetting some 85 percent of the projected incremental demand for electricity in 2030.

However, the report warns that private sector innovation and policy support will be necessary to unlock these and other opportunities. The report analysis focused on options likely to yield greenhouse gas reductions at a cost of less than $50 per ton of CO2 equivalent (CO2e). Among the main findings:

* Opportunities to reduce greenhouse gas emissions are highly fragmented and widely spread across the economy. The largest single option, carbon capture and storage (CCS) for coal-fired power plants, offers less than 11 percent of total potential identified. The largest sector, power generation, accounts for less than one third of the total.

* Reducing emissions by 3 gigatons of CO2e in 2030 would require $1.1 trillion of additional capital spending, or roughly 1.5 percent of the $77 trillion in real investment the U.S. economy is expected to make over this period.

* Investment would need to be higher in the early years, in order to capture energy efficiency gains at lowest overall costs and accelerate the development of key technologies, and would be highly concentrated in the power and transportation sectors.

* If pursued, such investment would likely put upward pressure on electricity prices and vehicle costs. Policymakers would need to weigh these added costs against the energy efficiency savings, opportunities for technological advances, and other societal benefits.

* Five clusters of initiatives, pursued in unison, could create substantial progress towards the targets implied by bills currently before Congress. From least to highest average cost, they are: Improving energy efficiency in buildings and appliances (710 to 870 megatons); Increasing fuel efficiency in vehicles and reducing carbon intensity of transportation fuels (340 to 660 megatons); Pursing various options across energy-intensive portions of the industrial sector (620 to 770 megatons); Expanding and enhancing carbon sinks, such as forests (440 to 590 megatons); Reducing the carbon intensity of electric power production (800 to 1,570 megatons.)

The report was produced in association with DTE Energy, Environmental Defense, Honeywell, National Grid, Natural Resources Defense Council, PG&E and Shell.

Update: Dec 20, 2007


The U.S. Environmental Protection Agency has denied California12s waiver request to regulate carbon dioxide (CO2) emissions from automobiles starting in 2009. The CO2 rules were issued by the California Air Resources Board and adopted by 12 other states. The EPA overturned the regulations on the same day that President Bush signed into law an energy bill to raise the Corporate Average Fuel Economy (CAFE) Standards for passenger cars and light trucks by 40% to an industry average of 35 miles per gallon by 2020. SEMA worked with the automakers and other industry associations as part of the CAFE Coalition to help negotiate a compromise to the new fuel economy standard.

Under the new federal law, the amount of renewable fuel used will increase to at least 36 billion gallons. According to the EPA, the new CAFE law and renewable fuel provisions will achieve greater greenhouse gas savings than the California program. Additionally, the federal approach provides a national solution, as opposed to a potential patchwork of state rules.

Under the Clean Air Act, California may seek a waiver to establish its own air quality rules (which can then be adopted by other states). This is the first time the EPA has completely rejected a waiver request. The agency noted that previous waiver petitions covered pollutants that predominantly impacted local and regional air quality. The EPA reasoned that a national framework for addressing greenhouse gases is necessary since the emissions are global in nature and impact every state.

California intends to appeal the EPA decision. Additionally, the Supreme Court recently directed the EPA to study the problem of greenhouse gases, paving a path to for EPA to potentially recommend even more stringent regulations if, in consultation with the National Highway Traffic Safety Administration, it deems them necessary.

More to come . . . . . .


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