in the trenches/climate

 

1. In Twelve Hundred Words or Less

 

Updated 12/17/1997

In December 1997, official negotiators from over 150 countries gathered in Kyoto, Japan, to decide if mandatory objectives would be imposed to address the most critical environmental problem of our time: humanity's large-scale, inadvertent experiment on the world's climate system. An agreement was adopted to require industrialized nations to make significant cuts in their emissions of warming gases over the next ten to fifteen years. To achieve this, industrialized countries will have to make reductions in their use of fossil fuels, such as coal and oil, and begin a gradual transition towards a new industrial system, based on efficiency and renewable energy. But what was the scientific basis for this unprecedented agreement?

SCIENCE BACKGROUND

The Earth's atmosphere is transparent, allowing sunlight to enter and warm its surface. Some of the gases in the atmosphere, including water vapor, carbon dioxide, methane, and nitrous oxide, are called greenhouse gases, because they trap some of this heat. Without the natural greenhouse effect, much of the sun's warmth would be lost to space, and the surface of the world would be about 61 degrees Fahrenheit colder, too frigid for most forms of life to have evolved.

Since industrialization, however, the levels of many greenhouse gases in the atmosphere have risen substantially, due mainly to the increased combustion of fossil fuels (coal, oil and natural gas), used to produce electricity, drive cars, run factories, and heat and cool houses. Greenhouse gases have also been emitted as a result of deforestation and various agricultural practices. The accumulation of these gases is changing the EarthÍs climate by trapping more of the sun's energy.

The globally-averaged temperature of the air at the Earth's surface has warmed between .5 and 1 degree Fahrenheit since the late nineteenth century. Eleven of the warmest years on record have all occurred since 1980, and the 1990s as a whole are the warmest decade so far. The sea level has also risen about 4 to 10 inches since the nineteenth century.

In 1988, in recognition of the seriousness of this problem, the governments of the world appointed the Intergovernmental Panel on Climate Change (IPCC), consisting of over 2000 leading scientists from around the world, to assess the science and economics of climate change. In 1996, the IPCC projected that the average surface temperature of the Earth will rise another 2 to 6 degrees Fahrenheit by the year 2100, with continued increases thereafter, unless concerted measures are adopted to limit the emissions of greenhouse gases.

The IPCC also concluded that at least part of the observed global warming over the last century was most likely the result of human activities, and that "the balance of evidence suggests a discernible human influence on global climate". The IPCC projected several probable consequences of future warming, including that the sea level would rise an additional 6 to 37 inches by the year 2100, and the frequency and the duration of many extreme weather events, such as heat waves and droughts, would increase. Heavy rains and flooding were also predicted to occur more frequently in many parts of the world, since higher temperatures lead to higher average rates of evaporation and precipitation.

In the United States, where the best data are available, statistical analysis shows that an increased number of extreme rainfall events has already been observed. This increase is expected to cause more frequent flooding in many areas, analogous to what occurred last winter, when record amounts of snow and rain fell on the Western United States.

IMPACTS

The IPCC has projected that climate change is likely to have wide-ranging and mostly adverse effects on human health. The greater frequency of heat waves is expected to raise mortality rates from heat stress, and to enlarge the potential ranges of many infectious diseases, bringing malaria and dengue fever into the temperate zone, for example, including parts of the United States.

With 50-70% of the global human population living near the coast, sea level rise and higher storm surges will increase by many millions the number of people whose homes are subject to periodic floods or permanent submergence. Moreover, in many parts of the tropics such as Africa, where inhabitants are already prone to malnutrition and famine, harvests may decline as a result of climate change. In some temperate regions, agricultural production could increase, but by how much depends upon the countervailing effect of other factors, such as the degree to which climate change will lead to the proliferation of pests and weeds.

Global warming also has the potential to transform many of the world's natural ecosystems over the next century, causing, for example, about one-third of the Earth's forested area to undergo major shifts in composition. Among ecosystems most likely to experience significant disruption are those at higher latitudes, such as far northern forests and tundra, as well as coastal ecosystems, with damaging consequences for fisheries and marine biodiversity.

RESPONSES

Addressing the problem of climate change in an effective and timely manner is probably the most serious challenge the nations of the world have ever faced. Some warming is already inevitable, given past emissions, since once released, most greenhouse gases remain in the atmosphere for a century or more. There is also a substantial lag in the system, as a result of the thermal inertia of the oceans. In general, political systems respond inadequately in anticipation of future threats. Moreover, in this case, there are many powerful interests arrayed against taking action, including the fossil fuel industry and its allied unions, the OPEC countries, and many sectors of the world's economy that rely heavily on the use of fossil fuels, such as the auto, chemical and metal industries.

Nevertheless, every business, as well as every nation, will have to adopt new practices if climate change is to be minimized. Though the industrialized countries, especially the United States, lead the rest of the world in per capita emissions, and are expected to do so into the indefinite future, the total emissions of developing nations are growing at a faster rate, and are expected to surpass those of the industrialized world during the next century. Whether developing countries can be persuaded to enter into binding agreements to restrict or cap their greenhouse emissions is still an open question, and will probably depend on whether they believe they will be able to develop fast enough by adopting a more technologically advanced energy path, and whether they expect to be sufficiently assisted in doing so by the richer, industrialized nations. In addition, the issue of whether they can be induced to adopt mandatory emission controls is also expected to influence whether the US Senate can be induced to ratify the climate treaty adopted in Kyoto. (For more on these questions, see New in the Literature and Technological Breakthroughs.)

 

More on Climate:
Table of Contents | Twelve Hundred Words or Less... | Web Resources
Activist Groups | Voices | New in the Literature | Hotspots
History of Climate Negotiations | Glossary of Negotiator Terms | On the Other Hand...
Policy Options | Technological Breakthroughs? | Want to Get Involved?
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