Global Warming: Possible Actions

What, if anything, can be done to prevent these greenhouse gas concentrations from rising to unacceptable levels? Energy policy is certainly one area in which changes can be made to reduce CO2 emissions. Greater emphasis on energy conservation, economic incentives, renewable-energy technologies, and nuclear power are a few of the options. Natural gas-fired electricity produces about 60% less CO2 per kWh generated than coal, and the use of gas is growing. We must also be aware of how much our own activities produce CO2. An American emits on the average 20 metric tons of CO2 per year—six times more than a person in a developing country. Table 9.4 depicts CO2 production for some common activities. (It is interesting to do some simple calculations to substantiate these numbers. See Problems 16 and 17.) Increased energy efficiency will also cut down on emissions while allowing us to maintain the same level of activity.

Two forms of legislative action that can tackle the issue of global warming are “cap and trade” policy and a carbon tax. In cap and trade, a limit on emissions is instituted, but one that allows utilities and other industries to adopt the most cost-effective strategy for meeting those limits. A company can buy and sell permits to comply with the law. A company that pollutes less than its allowance can sell excess permits to those who pollute more. This approach has worked well in reducing atmospheric concentrations of NO^ and acid rain. However, the complexity of cap and trade, our current economic difficulties, and the perception that this is just another tax, has made this approach a failure, so far.

A carbon tax is a tax on the amount of CO2 produced—as so many dollars per ton of carbon emitted. This tax encourages reduced consumption and increased efficiency. It also makes renewable fuels more cost competitive. However, there is much opposition to this form of pollution tax. Sweden (in 1991) and other northern European countries later use such a tax. Since then CO2 emissions have been reduced by 10—20% over what they would have been. There has been a substantial increase in the use of biofuels in these countries.

One approach being actively pursued to reduce the amount of CO2 being added to our atmosphere is carbon sequestration. The goal here is to capture carbon at its source and direct it to nonatmospheric sinks. This can be done by several methods:

1. By capturing or absorbing the CO2 generated after combustion in a solvent (prob­ably amine—a derivative of ammonia)

2. By turning the coal into a gas prior to combustion and easily separating it from combustion gases

3. By directing the CO2 to more efficient terrestrial ecosystems (forests, vegetation, and soils), or industrial users (such as local soft drink manufacturers)

However, all of these methods are costly financially and energy-wise. All of these approaches will need to use extremely large geologic storage volumes in the right place. Depleted oil and gas reservoirs, deep saline formations—onshore or offshore—and CO2 in enhanced oil recovery are all possibilities. The use of high-pressure CO2 in oil and gas reservoirs for enhanced recovery has been used for many years. The fact that oil and

Подпись: Table 9.4 INDIVIDUAL CARBON DIOXIDE PRODUCTION Use Basis CO2 Emissions (lb) Car Per gallon 20 Electricity Per kWh (using coal) 2 Natural gas Per therm (for heating) 12

gas have been retained in these reservoirs for eons is an indication that CO2 will not easily escape. Worldwide, there seems to be ample geologic volumes available for carbon sequestration. Many worldwide demonstration projects are underway, including a 1 million tons per year plant in Utah. A Norwegian company is currently sequestering 1 million tons per year of CO2 in deep sandstone volumes under the North Sea.

For these approaches to be effective globally, international strategies must be de­veloped and followed. Most governments have a built-in bias against solving long-term problems. Steps to slow the rate of global warming will be costly and controversial. Regulations on fossil fuel use certainly will be burdensome on some groups, and devel­oping nations will be hard-pressed to agree to controls on fossil fuel combustion and increased energy conservation.

In June 1992, at the Earth Summit in Rio de Janeiro, 167 nations ratified the U. N. Framework Convention on Climate Change. One of the documents (the “Rio Declara­tion”) stressed that one nation can no longer do anything it wants with its environment without regard to the impact on other countries. The “Climate Convention” treaty established a goal to stabilize (at 1990 levels) carbon dioxide and other greenhouse gases emissions by the year 2000. However, this agreement was voluntary and developed nations failed to attain the emission restrictions. In fact, U. S. CO2 emissions grew more quickly than anticipated due to economic growth, lower energy prices, and slower gains in energy efficiency and renewable energy technology penetration into the marketplace.

Подпись: ACTIVITY 9.2 Calculate the amount of carbon dioxide emitted annually by your household. You will have to estimate the amount of electricity, natural gas, and gasoline used. Use the approximate conversions of Table 9.4. In December 1997, another international conference on the environment was held in Kyoto, Japan. (See Focus On 1.3, the Kyoto Protocol on Climate Change.) The nations developed a protocol that aimed to cut emissions of greenhouse gases by de­veloped countries by 5% from their 1990 levels by the year 2010. However, the Kyoto Protocol did not set any binding limits on emissions from developing countries. Partly due to this, the U. S. Senate has not ratified this treaty. By 2005, enough countries (141) had ratified this protocol that it went into effect. In 2012, the commitment period for this protocol ends.

A climate change conference in 2010 in Can cun made no agreement to extend the Kyoto limits to ad­vanced developing nations. There was progress, how­ever, on granting technical and financial assistance to poorer countries in making emission reductions.

The political consequences of a global temper­ature rise of several degrees and the accompanying



hina became the world’s largest emitter of greenhouse gases in 2007.

I mpacts of global warming have been discussed at top levels of the central government for years—with concerns over rising sea levels, desertification, and extreme weather incidences. Changes in water availability and rising temperatures could lead to severe decreases in agricultural output. China is a vast country with very diverse regions that will be affected differently Several government – sponsored approaches to this situation involve improved industrial energy efficien­cies, higher fuel-economy requirements for its vast automobile market, and more emphasis on renewables and nuclear power: One goal is to have 15% of its elec­trical energy coming from renewables by 2020. In the past several years, hundreds of older coal-fired power plants have been closed. China is also the world’s largest manufacturer of wind turbines and solar cells. China has also agreed to an interna­tional effort to phase out incandescent light bulbs by 2020.

However rising demand from a growing economy (GDP growth of about 9% per year) could offset most of these steps. Consumer calls are for bigger cars, more electric home appliances, and more creature comforts such as air-conditioned shopping malls and apartments with cooler temperatures. As a result, China is be­coming even less energy efficient. As a country becomes more dependent on do­mestic demand instead of exports, growth moves away from manufacturing of toys and clothes toward energy-consuming heavy industries such as steel and cement production. And because most of the energy in China is produced by burning coal, China’s emissions of carbon dioxide are growing worse (see Fig. 9.11). Even with the steps China has taken, many project that China’s emissions of energy-related greenhouse gases will grow more than the rest of the worlds combined increases by 2020. China’s problem might grow to dominate the world’s problem.

Energy Production: People’s Republic of China

Global Warming: Possible Actions

Figure 9.11 Energy use in China by fuel, in units of Million tons of oil equivalent, 1972-2008. (Source: © OECD/International Energy Agency 2010)

changes in regional climates and agricultural productivity can be unsettling. The at­mosphere appears to be sensitive to even small chemical changes, so there is also the possibility of unwanted surprises occurring in shorter times than forecasters might envi­sion. (How might we attribute the unusual [and deadly] outbreak of tornadoes [more than 1400] that swept across the southern United States in the spring of 2011?) Govern­ments are held accountable on matters involving national security and the basic free­doms of its citizens. Should they also be aware of the environmental costs to a society that has the “freedom” to experiment with its own future?