The Kyoto Protocol to the Framework Convention on Climate Change was negotiated by over 160 countries in December 1997. The agreement would require 38 industrialized countries to reduce the emissions of six major greenhouse gases by 5.2 percent during the 2008-2012 period (See Kyoto Protocol targets: Emission limitations and reduction requirements). The Kyoto Protocol follows the 1992 Framework Convention on Climate Change, which established the objective of stabilizing atmospheric concentrations of greenhouse gases "at a level that would prevent dangerous interference with the climate system."

The Kyoto Protocol, however, faces many formidable obstacles which the negotiating parties have found difficult to resolve since the Kyoto conference. Specifically, the agreement establishes a set of complex policy instruments that are expected to help industrialized countries achieve their emissions targets at lower overall costs. These "Kyoto Mechanisms" include emissions trading among industrialized countries and the Clean Development Mechanism that aims to help developing countries achieve sustainable development through greenhouse gas-reducing projects financed by industrialized countries. These mechanisms hold great promise for lowering the costs of tackling climate change.

But many of the rules and principles governing these instruments are yet to be resolved. What happens if a country sells emission permits, but does not comply with its domestic targets? What should the preconditions be to participate in emissions trading, and what kinds of projects should be eligible to generate credits through the Clean Development Mechanism? Should limits be placed on the use of emissions trading and project-based efforts to reduce emissions? Many of the rules and modalities governing other critical issues, such as compliance and financial assistance, were also left unanswered in Kyoto.

To address all of the unresolved issues, delegates adopted the "Buenos Aires Plan of Action" at the fourth Conference of the Parties in November 1998. More recently, at the fifth Conference of the Parties in November 1999, countries renewed their commitment to resolving by November 2000 the key issues that will make the Kyoto Protocol operational. A common understanding of the issues contained in the Buenos Aires Plan of Action will be required before many countries ratify the treaty. And until 55 countries, representing 55 percent of the emissions of industrialized countries ratify the Kyoto Protocol, it will not enter into force and become legally binding upon countries. The prospects of widespread ratification and entry into force of the Protocol depend heavily on the timing and degree of progress under the Buenos Aires Plan of Action.

A more fundamental issue is the likelihood and practicality of reaching the country targets established by the Kyoto Protocol. Thus far, very few industrialized countries have taken the concrete domestic actions necessary to reach the 2008-2012 target emission levels. Emissions of the major greenhouse gases in the United States, the world's leading emitter, are already about 11 percent higher than 1990 levels. Furthermore, according to US Department of Energy forecasts, carbon emissions in the US are expected to reach 33 percent above 1990 levels by 2010 in the absence of policy changes that reduce energy use and change consumer behaviors.

Among the countries that have made binding commitments under the Protocol, only those of central and eastern Europe and the former Soviet Union have emissions below target levels. However, these emission decreases are for the most part due to economic decline, rather than improvements in energy efficiency and the development lower carbon energy sources.

If the outstanding issues are resolved and the Kyoto Protocol does enter into force, what overall impact will it have on future global emission levels? One the one hand, relative to emissions levels that are expected in 2010 without emissions-control measures, the Protocol represents a 30 percent reduction for industrialized countries. Thus, the agreement should encourage governments to improve energy efficiency, reform the energy and transportation sectors, protect forests and other carbon "sinks," promote renewable forms of energy, and phase out existing incentives that promote the wasteful use of energy.

However, according to global carbon emission projections, even with the implementation of this agreement, emission levels in 2010 are still expected to be more than 30 percent higher than 1990 levels (See Figure How Much Will the Kyoto Protocol Reduce Emissions?). In other words, the emission cuts by industrialized countries will be more than offset by emission increases from countries that are not bound by emission limitations under the Kyoto Protocol, many of which are currently undergoing rapid economic development.

Treaty negotiators and observers acknowledge that the Kyoto Protocol is only a first step toward more comprehensive and ambitious emission reduction efforts. Regardless of the scope of near term participation under the Kyoto Protocol, stabilizing the atmosphere and preventing dangerous climate change (the objective of the 1992 Climate Convention) will necessarily require steep reductions in global emissions. For instance, stabilizing atmospheric concentrations of CO2 at twice the pre-industrial level (560 ppmv) would require a reduction in emissions of 60 percent below 1990 levels. And even an atmosphere with this level of CO2 would not necessarily prevent dangerous climate change. Beginning global emission reductions sooner rather than later would result in less drastic future cuts (and less costly for future generations) required to achieve a given stabilization target.