Nations Must Reduce Greenhouse Gas Emissions To Their Fair Share of Safe Global Emissions Without Regard To What Other Nations Do

I. Introduction

One frequently hears the argument that it would be unfair to the United States to commit to reduce its greenhouse gas emissions because some large emitting countries including China and India have not done so. Although this argument has waned somewhat since it was first strongly made in opposition to the Kyoto Protocol, recently this contention has arisen again in response to proposed new US climate change laws and in discussions about what the US position should be when it negotiates a post-Kyoto regime this December in Poland and next December in Copenhagen.

In response to this argument, proponents of US government emissions reduction commitments often argue that the world needs the United States to take action to show leadership to the rest of the world even if China and India do not commit to binding emissions reductions targets. This response appears to concede that the United States has no duty to act until other emitting nations agree to act but, nevertheless, the United States should act to show “leadership” to reduce climate change’s great threat. The ideas seems to rest on the conclusion that if the United States acts to reduce emissions others will follow and therefore as a matter of “prudence” the US should make commitments given climate change’s potential catastrophic impacts. This position seems to concede that the United States has no ethical obligation to reduce its greenhouse gas emissions, the reason for moving ahead despite the fact that other countries have not done so is the practical need to show leadership. Can a case be made that the United States and other high-emitting nations have an ethical duty to reduce greenhouse gas emissions even if other nations do not do so?

Some developing nations have argued that since they have not made major contributions to the climate change problem, they should not be expected to take action until developed countries have reduced their emissions. They often make this claim based upon the undisputed fact that developed nations’ emissions far exceed developing nations’ emissions levels. Do these developing nations also have a duty to reduce their greenhouse gas emissions under any circumstances?

In thinking about national responsibility, certain facts are particularly relevant. These facts include:

  • Nations differ in levels of GHG emissions, whether measured by total emissions, per capita emissions, or emission per unit of GDP.
  • Nations differ in regard to actions taken to reduce the threat of climate change.
  • Developed nations are responsible for the majority of past and current greenhouse emissions.
  • Some developing countries will soon surpass developed nations in total GHG emissions, but per capita emissions in developed countries are likely to exceed per capita emissions in developing countries for the foreseeable future.
  • Under the United Nations Framework Convention on Climate Change (UNFCCC), the developed nations agreed that they would reduce GHG emissions on the basis of “equity” to prevent dangerous anthropogenic interference with the climate system. (UNFCCC, Art 3, 1992)
  • The developed nations also agreed that they would “take the lead in combating climate change and the adverse effects thereof” (UNFCCC, Art. 3. 1992).
  • Current emissions levels will need to be reduced significantly more than 60 percent to avoid serious climate change damages. The actual reduction level necessary to reduce emissions beyond current levels will depend upon when emissions reductions are undertaken, the amount of damage from climate change that should be accepted by the international community as a matter of ethics, and ethical duties to act in the face of uncertainty about what damages will flow from different levels of atmospheric concentrations of greenhouse gases. (See Climateethics post on scientific uncertainty,

Some people and nations, more than others, are particularly vulnerable to human-induced climate change.
This post examines ethical issues entailed by the fact that some nations have taken or have committed to action to reduce emissions and others have made no such commitment. (A former post on Climateethics examined some of these issues, i.e., Nations Must Follow Justice In Climate Change Negotiations. This post expands upon matters examined in this earlier post)

II. Ethical Duty To Act Does Not Depend On Other National Greenhouse Gas Emissions Reduction Commitments

Because current greenhouse gas levels are already harming people, plants, animals, and ecosystems around the world according to the consensus climate change scientific view, and even if global emissions could be stabilized at current levels (a difficult goal to achieve), climate change caused harms will grow in the years ahead. For this reason, current levels of total global greenhouse gas emissions must be reduced significantly to avoid future harm especially to those who have done little to cause the existing problem.

Yet, not all nations have equal responsibility to reduce greenhouse emissions given differences among nations in current and past emissions levels and steps already taken to reduce national emissions. However, all nations have an ethical duty to reduce their greenhouse gas emissions to their fair share of safe global emissions if they are exceeding their fair share. (See post about what justice requires at
Differences in current and past emissions levels, actions already taken to reduce emissions, equal rights of humans to use the atmosphere, and several additional morally relevant criteria should be considered in determining each nation’s fair share of safe global emissions. (What ethics requires in determining fair national allocations of greenhouse gas emissions will be the subject of several upcoming posts on In these posts, the case will be made that different ethical theories will lead to different ethical conclusions as to what is a nation’s fair share, yet not all assertions of fairness are entitled to ethical respect. In fact some current national proposals of what fairness requires of them do not pass minimum ethical scrutiny.)

Yet, as a matter of distributive justice, no nation can deny that it has a duty to keep its national emissions levels below its fair share of safe global emissions. Therefore if a nation is exceeding its fair share of safe global emissions, that nation has an ethical duty to reduce emissions and this duty does not depend upon what other nations are doing.

Although some developing nations can make a presentable argument that they could increase GHG emissions without exceeding their fair share of global emissions, the developed nations cannot make this argument because it is known that existing emissions levels need to be significantly reduced and the developed nations are very high emitting nations. For this reason, the United States and other developed nations, along with perhaps a few developing nations, have a duty to begin to reduce their emissions to their fair share of safe global emissions and this obligation is compelled by justice, not a need for leadership. In fact, even developing nations have a duty to keep their emissions below their fair share once they exceed their fair share. The duty to reduce emissions is not diminished if others who are contributing to the harm fail to cease their harmful behavior. This is so because no nation or person has a right to continue destructive behavior on the basis that others who are causing damage have not ceased their destructive behavior. The only question that needs to be examined to trigger a responsibility to begin reductions is whether the nation is exceeding its fair share of safe global emissions.
In addition to principles of distributive justice, developed nations have another strong reason why they must reduce their emissions to their fair share of safe global emissions. That is, as we have seen, they promised to do reduce their emissions based upon “equity” in the Untied Nations Framework Convention on Climate Change to prevent dangerous anthropocentric interference with the climate system. Violating a provision of an international agreement such as the UNFCCC is considered a wrongful act under international law, and is therefore an unethical action for consenting nations. (See, e.g., International Law Commission Draft Articles on State Responsibility Art. 2(a) & (b). Since parties to the UNFCCC also agreed that Annex I countries, that is developed countries, would take the lead in combating climate change and modifying future trends, Annex I countries must undertake policies and measures to limit their emissions regardless of actions taken by non-Annex I country Parties. This is now a matter of international law as well as a principle of distributive justice.

For these reasons, high emitting nations in particular have a legal and ethical responsibility to reduce emissions to their fair share of safe global emissions. This duty applies regardless of efforts undertaken by other nations. Later posts will examine in more detail what “fairness” and “safety” requires.


Donald A. Brown
Associate Professor, Environmental Ethics, Science, and Law
Program on Science, Technology, and Society
The Pennsylvania State University


Brown, Donald A. The Ethical Duty to Reduce Greenhouse Gas Emissions in the Face of Scientific Uncertainty, Climateethics,

Brown, Donald A. Nations Must Follow Justice In Climate Change Negotiations,

International Law Commission, Draft Articles on State Responsibility,,

United Nations, United Nations Framework Convention on Climate Change (UNFCCC), 1992. UN Document, A:AC237/18.


One thought on “Nations Must Reduce Greenhouse Gas Emissions To Their Fair Share of Safe Global Emissions Without Regard To What Other Nations Do

  1. Very good post, all is fine. This recquires knowledge that climate change is a problem and that it needs solution. How many people recognizes that? When I talk with my friends (with normal education and intelligence) about issues like climate change and the future, the obvious answer is: “I don’t care what will by in 50 years” or “Technology breakthroughs will solve the problem in the future…” If I say, we have the problem NOW, they say: “Is it really that serious, that I should change my habits…?”


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