We are often awed by how fine-tuned our planet is for the existence and continuation of life. One factor that makes this possible is its atmosphere, which is designed to filter out harmful radiation and meteors from space. While solar radiation is largely absorbed, some is reflected by the planet and the atmosphere. Some of the radiation reflected or emitted by Earth passes through the atmosphere, while the rest is absorbed and emitted in all directions by some gases in the atmosphere. This reflected radiation, combined with the energy absorbed by Earth, enables life to exist here.
Since this phenomenon resembles the heat reflected by glass panels in a greenhouse, it is called the greenhouse effect. The greenhouse gases that contribute significantly to this process are carbon dioxide, methane, water vapor, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. The greenhouse effect is necessary for life, but too much of it is undesirable. Some negative consequences are changes in average temperature, precipitation, wind and ocean circulation patterns, polar glacier melting, and more storms, droughts, and floods.
The atmosphere is an extremely complex system that is not fully understood. During Earth’s long history, its atmosphere’s composition has experienced natural variations. By analyzing tree rings and core samples taken from Greenland and various high-altitude tropical areas, scientists have concluded that Earth has undergone several warming and cooling cycles. Among the factors that can cause such changes are greenhouse gases and ocean water salinity. According to Stant: “Since 1861 the Earth has warmed by about 0.5 degrees Celsius. Most of this warming took place before 1940, but much of it has taken place in the last 15 years. The global temperature of the Earth is projected to rise anywhere from 0.8 to 2.6 degrees Celsius in the next thirty to forty years.”1
Some scientists think that the most recent atmospheric changes are part of a natural variation. But there is a growing consensus that human activity, particularly the emission of greenhouse gases and especially the carbon dioxide produced by industrial activity, has played some role. Small amounts of such gases can be absorbed by forests and oceans, and thus do not represent a serious problem. But thanks to the Industrial Revolution, this system has been thrown out of balance. Other activities, such as increased agriculture, deforestation, and the widespread use of fossil fuels for transportation, industrial processes, and heating fuels have exacerbated it.
This article will summarize the latest findings on the potential impact of global climate change.
The vast majority of scientists now agree that business-as-usual may lead to irreversible change in Earth’s atmosphere. Global climate change became part of the political agenda in the developed world during the mid-1980s, a time of increasing environmental awareness and mounting public concern due to the efforts of Greenpeace, the Sierra Club, and other pro-environment groups. One assumption gradually emerged out of the numerous conferences, grassroots efforts, and publications: The developed countries are primarily responsible for the accumulation of greenhouse gases in the atmosphere, and therefore should take the lead in fixing the problem. The latest step taken to mitigate worldwide emissions was the Kyoto Protocol (11 Dec. 1998), which devised a formula to determine the amount of gases each country could emit. Although signed by 84 countries, it has to be ratified by at least 55 countries (emissions from which make up at least 55% of global emissions) before it can be enforced. This has not happened yet.
The United States, the major producer of greenhouse gases, has signed but not ratified the Kyoto Protocol. Hopes were high that the new Bush administration would do so. However, Bush soon reneged on a campaign pledge to regulate carbon dioxide emissions from U.S. power plants, and shortly thereafter repudiated the Kyoto Protocol. His claim that the scientific evidence for the greenhouse effect and its consequences was not yet convincing was greeted with disbelief. Questions were raised about corporate America’s role in forming his views, as many companies opposed the protocol and contributed heavily to his presidential campaign.
Fortunately, there is also mounting evidence that industry opposition, led by the oil, gas, and automotive concerns, is weakening. According to the Natural Resources Defense Council, “many businesses recognize global warming as a threat and realize that reducing emissions is in their economic interest. Several-including such giants as BP-Amoco, IBM and Johnson & Johnson-have voluntarily adopted emissions reductions stronger than those called for in the Kyoto Protocol.”2
The Intergovernmental Panel on Climate Change
The World Meteorological Organization (WMO) and the UN Environment Programme (UNEP) established the Intergovernmental Panel on Climate Change (IPCC) in 1988. Tasked with assessing the scientific, technical, and socioeconomic data needed to understand the risk of human-induced climate change, its mission is to provide policymakers with the most current scientific data on global climate change. The IPCC serves as a good example of how scientists from different backgrounds and countries come together to investigate a global problem. Some of its findings are summarized below.3
Agriculture and Food Security. In principle, increased levels of carbon dioxide should benefit agriculture. However, one has to consider subsequent regional changes in rainfall and the reaction of crops, soil, and pests. Moreover, excessive heat and drought might have a negative impact on crop yield.
The overall effect on crop yield is predicted to be positive, especially in such colder regions as Canada and Russia, if the rise in average temperature does not exceed several degrees Celsius. If it does, the effect will be negative. In tropical regions, where crops are already near their maximum heat tolerance, even a minimal increase in temperature is predicted to have a negative effect on crop yields. The number of people at risk of hunger, especially in Africa, is expected to increase. The most vulnerable populations will be those who depend heavily on agriculture and those living in developing countries.
Ecosystem Damage. Ecosystems react to climate changes much slower than people. Wildlife habitat distribution and composition will be directly influenced by any change in temperature and rainfall, and indirectly by any change in vegetation. Most likely, species will not have enough time to adapt. This will be exacerbated by the continuing fragmentation of wildlife habitats by human settlement, which makes migration infeasible for most species. Since migration is unlikely, species composition and dominance will change, and endangered species will face extinction. Changes in ocean circulation will affect fish abundance and habitat boundaries, as well as fish population dynamics. This might have a significant impact on fish-dependent societies.
Rising Sea Levels. This is perhaps the most worrisome impact category. The IPCC Working Group I reports that as a result of melting polar glaciers, the global sea level will rise anywhere from 0.09m to 0.88m. Oceans cover a large part of the planet and have a significant impact on its climate. Wind and circulation patterns also are affected by changes in sea level and sea-surface temperature.
If the rises are high enough, many of the generally accepted models indicate that small islands will be submerged, many coastal areas will be inundated, and freshwater resources will face seawater intrusion. In addition, large coastal areas will be evacuated, populations will have to migrate, and wetlands and mangrove forests will be lost. Such countries as Bangladesh, which depends heavily on mangroves, will be devastated. The fishery industry will suffer as fish abundance and location change.
And, as if all of this were not enough, there also might be a rise in the frequency and severity of storms and sea-surges. Countries that depend largely on coastal tourism will suffer. Although people will see the approaching catastrophes and try to protect themselves by building seawalls, nourishing beaches, and other measures, not all of the impact will be cancelled.
Health Sector. There will be fewer complaints about the cold during the winter, but more complaints about the heat during the summer. Whether the benefits will outweigh the costs depends on the region. Tropical regions will face more deaths from heat stress. In addition, the influence areas of vector-, food- and water-borne diseases will shift. For example, depending on changes in rainfall and average temperature, malaria or dengue fever might become more widespread.
Although the specific impact depends on a wide variety of local conditions, such as the health infrastructure and socioeconomic conditions, the overall effect is predicted to be negative, especially in developing countries. Such extreme climate-related events as cyclones, floods, and droughts might become more common and severe, and thus leave exposed populations with even more health problems.
What Needs To Be Done
For each anticipated impact category (and for others not included here),
there is a wide range of institutional, technological, and behavioral adaptation measures that can be pursued to minimize damage. The IPCC report contains many suggestions. Governments should become aware of the consequences of global climate change and start working to increase public awareness. As most measures might take decades to plan and implement, any delay only makes the problem harder to solve.
In addition, greenhouse gas emission rates have to be decreased. The time for playing around has passed. Governments and people in positions of power, as hard as it might be, should agree on a global approach and then set about implementing it. There have been some advances, but not enough. Developed countries, having caused the global warming problem, should take the lead in implementing the Kyoto Protocol as soon as possible.
A key ingredient is technology transfer. Most developing countries are still building industrial, energy, and distribution infrastructures. Developed countries should try to ensure that only the latest and cleanest technologies are installed so that the solution is not only postponed to a later date.
This is vital in China, now home to almost one-fourth of humanity and undergoing rapid economic growth and development. Given its size, its development policies will have a global impact. According to Mark Hertsgaard, who spent 6 weeks in China studying this issue: “China is … the world’s second largest producer of greenhouse gases, trailing only the United States. With its immense coal reserves, huge population, and booming economic growth, China is very likely to triple its greenhouse emissions by 2020 .... If outsiders want China to do something about global warming, they will have to pay for it. As one Western consultant with regular access to senior Chinese officials puts it, “They know very well they can hold the world for ransom ... and whenever they can extract concessions, they will.”4
Many people in the developing world might object to “hold the world for ransom” for a quite logical reason: When the now-developed countries were developing, environmental damage and pollution were non-issues. Now that others are trying to develop, the developed world wants to maintain the status quo, which is stacked in its favor, by raising standards. This charge must be addressed in such a way that those making it will accept proposed environmental regulations and policies.
A Recent Development
On July 26, 2001, Japan and other nations joined Europe in accepting the Kyoto Protocol. But the price might have been too high: a scaling back of carbon dioxide reductions, the acceptance of “carbon sinks” (that forests and other environmental reatures would absorb more greenhouse gases), and that violators would not be penalized. President Bush has not yet revealed his promised alternative.
Global climate change, as the phrase indicates, is a global challenge that requires a great deal of attention and resource concentration. However, it also requires political will. This is especially true with China, which endured great famines and poverty during the twentieth century. Hoping to avoid any repetition, China has embraced the late Deng Xiaoping’s policy of “to get rich is glorious.” If it comes down to a choice between development and the environment, China and other developing countries just might choose development.
Western businesses claim that the developing world will gain an unfair competitive edge if its companies are exempt from existing environmental regulations. But instead of showing such countries see that environmental protection is in their own long-term interest and helping them acquire and implement the latest technology, many Western companies relocate in countries with lax and easily subverted environmental legislation. Such short-sighted policies increase the problem’s severity, for it shows that the developed world does not really care about the environment. If this is so, how can it expect the developing world to care about it?
Hopefully, nations will find a way to protect their environments while enjoying double-digit growth figures, and their scientists and politicians will find the necessary will to solve this problem
1 Linda Ruth Stant, “Changes in the Earth’s Climate for the Past Two Million Years.” Online at: http://www.gly.fsu. edu/~kish/dynamic/global/LS.htm.
3 The findings are taken from “Summary for Policy Makers: Climate Change 2001: Impacts, Adaptation and Vulnerability.” The summary of the Working Group II report is online at: www.ipcc.ch.
4 Mark Hertsgaard, “Our Real China Problem,” The Atlantic Online (Nov. 1997). Online at: http://www.theatlantic.com/issues/97nov/china.htm
U.S. Environmental Protection Agency. Online at: www.epa.gov/globalwarming.
UN Framework Convention on Climate Change. Online at: www.unfccc.de.