21-7 Dealing with the Threat of Global Warming
What Are Our Options? The Great Climate Debate
Economists and policymakers also disagree over how we should respond to the threat of climate change. They disagree on whether:
the economic costs of reducing greenhouse gas emissions are higher than the economic benefits;
Economists and policymakers also disagree over how we should respond to the threat of climate change. They disagree on whether the economic costs of reducing greenhouse gas emissions are higher than the economic benefits;
actions to reduce greenhouse gas emissions should be voluntary or required as a result of national laws and an international treaty
As a result of these scientific, economic, and political disagreements, there are three schools of thought concerning what we should do about projected global warming:
One is to do more research before acting. With this wait-and-see-strategy, many scientists and economists call for more research and a better under- standing of the Earth’s climate system before making far-reaching and controversial economic and political decisions such as phasing out fossil fuels. This has been the pre-Obama position of the U.S. government
A second and rapidly growing group of scientists, economists, business leaders, and political leaders especially in the European Union believe that we should act now to reduce the risks from climate change brought about by global warming. They argue that the potential for harmful economic, ecological, and social consequences is so great that action should not be delayed.
A third strategy is to act now as part of a no-regrets strategy. Scientists and economists supporting this approach say we should take the key actions needed to slow global warming—even if the threat does not materialize—because such actions lead to other important environmental, health, and economic benefits
What Can We Do to Reduce the Threat? Conserve Energy, Use Renewable Energy, and Intercept Greenhouse Gas Emissions
There are a a variety of prevention and cleanup solutions that climate analysts have suggested for slowing the rate and degree of global warming. The solutions come down to three major strategies: improve energy efficiency to reduce fossil fuel use; shift from carbon-based fossil fuels to a mix of carbon- free renewable energy resources; and sequester or store as much CO2 as possible in soil, in vegetation, underground, and in the deep ocean. The effectiveness of these three strategies would be enhanced by reducing population growth to decrease the number of fossil fuel consumers and CO2 emitters and by reducing poverty to decrease the need of the poor to clear more land for crops and wood.
Can We Remove and Store (Sequester) Enough CO2 to Slow Global Warming? Are Output Approaches the Answer?
There are several potential techniques to remove CO2 from the troposphere or from smoke- stacks and store (sequester) it in other parts of the environment:
One possible way to remove CO2 from the atmosphere is to plant trees that store (sequester) it in bio- mass. While it is true that trees release their stored CO2 once they die and decompose, or burn, the idea is to increase the total area of forested land in the world. Preventing deforestation, and increasing reforestation, would sequester CO2 and add ecological benefits. Furthermore, wood that goes into construction of buildings or into other long-lasting products represents stored CO2.
A second approach is soil sequestration in which plants such as switchgrass are used to remove CO2 from the air and store it in the soil. But warmer temperatures can increase decomposition in soils and return some of the stored CO2 to the atmosphere.
A third strategy is to reduce the release of carbon dioxide and nitrous oxide from soil. Ways to do this include conservation cultivation (Figure 14-12, p. 312) and retiring depleted crop fields, leaving them untouched as conservation reserves.
A fourth approach is to remove CO2 from smoke- stacks and pump it deep underground into unminable coal seams and abandoned oil fields or inject it into the deep ocean
How Can Governments Reduce the Threat of Global Warming? Use Sticks and Carrots
Governments could use three major methods to pro- mote the solutions to slowing global warming:
One is to phase in output-based carbon taxes on each unit of CO2 emitted by fossil fuels (espe- cially coal and gasoline) or input-based energy taxes on each unit of fossil fuel (especially coal and gasoline) that is burned.
A second strategy is to level the economic playing field by greatly increasing government subsidies for energy-efficiency and carbon-free renewable-energy technologies, carbon sequestration, and more sustain- able agriculture, and by phasing out subsidies and tax breaks for using fossil fuels
The third strategy is technology transfer. Governments of developed countries could fund the transfer of energy-efficiency, carbon-free renewable- energy, carbon-sequestration, and more sustainable agriculture technologies to developing countries.
How Can We Use the Marketplace to Reduce or Prevent Greenhouse Gas Emissions? Emissions Trading
In a greenhouse gas emissions trading program, industries and countries could earn greenhouse gas emission credits by improving energy efficiency, switching from coal to natural gas, and adopting certain farming, ranching, and soil-building and conservation practices. Credits could also be earned by switching from coal and other fossil fuels to forms of carbon-free renewable energy such as solar, wind, hydrogen, and geothermal. For example, a coal-burning company in Illinois could earn emission credits by building a wind farm in Oregon.
In addition, credits could be earned by sequestering CO2 from the atmosphere by reforestation or by injecting it into the deep ocean or secure underground reservoirs (Figure 21-19). For example, a coal-burning power plant in Saskatchewan might earn credits by financing a CO2-removing reforestation project in New Brunswick or Costa Rica.
Some analysts believe this market-based approach is more politically and economically feasible than relying primarily on government regulation to impose taxes on carbon emissions or fuel used. Other analysts point to some problems with emissions trading. One is that carbon fuels are burned in so many homes, vehicles, factories, and crop fields that it would be difficult to monitor compliance. For that reason, many analysts think that emissions trading programs should be used in conjunction with other approaches, such as taxes on fossil fuel use, significant government subsidies for energy efficiency and renewable energy, and removal of subsidies for fossil fuels.
Can We Afford to Reduce the Threat of Global Warming? Not Acting Will Probably Cost More
Some economists project that the costs of reducing CO2 emissions will greatly exceed the projected benefits. Other economists criticize these models as being unrealistic and too gloomy for two reasons. First, they do not include the huge cost savings from implementing many of the strategies listed in Figure 21-18 such as improving energy efficiency. Second, they underestimate the ability of the marketplace to act rapidly when money is to be made from reducing greenhouse gas emissions.