By Donald A. Brown, Associate Professor (Environmental Ethics, Science, and Law - Penn State University)
If climate change is an ethical problem, then:
1. Nations or sub-national governments may not look to their domestic economic interests alone to justify their response to climate change because they must also comply with their duties, responsibilities, and obligations to others to prevent climate-change caused harms.
2. All nations, sub-national governments, businesses, organizations, and individual must reduce their greenhouse gas emissions to their fair share of safe global emissions. Although different theories of distributive justice would reach different conclusions about what "fairness" requires quantitatively, most of the positions taken by opponents of climate change policies fail to pass minimum ethical scrutiny given the huge differences in emissions levels between high and low emitting nations and the enormity of global emissions reductions needed to prevent catastrophic climate change. Any test of "fairness" must look to principles of distributive or retributive justice and must be supported by moral reasoning.
3. No nation may refuse to reduce its greenhouse gas emissions to its fair share of safe global emissions on the basis that some other nations are not reducing their emissions to their fair share of safe global emissions. All nations must reduce their greenhouse gas emissions to their fair share of safe global emissions without regard to what other nations do.
4. No national policy on climate change is ethically acceptable unless it, in combination with fair levels of greenhouse gas emissions from other countries, leads to stabilizing greenhouse gas atmospheric concentrations at levels that prevent harm to those around the world who are most vulnerable to climate change. This is so because any national position on climate change is implicitly a position on adequate global atmospheric greenhouse gas concentration stabilization level and all nations have a duty to prevent atmospheric greenhouse concentrations from exceeding levels that are harmful to others.
5. Because it has been scientifically well established that there is a great risk of catastrophic harm from human-induced change (even though it is acknowledged that there are remaining uncertainties about timing and magnitude of climate change impacts), no high-emitting nation, sub-national government, organization, business, or individual of greenhouse gases may use some remaining scientific uncertainty about climate change impacts as an excuse for not reducing its emissions to its fair share of safe global greenhouse gas emission on the basis of scientific uncertainty. The duty to prevent great harm to others begins once a person is on notice that they are potentially causing great harm, not when the harm is absolutely proven.
6. Those nations, sub-national governments, organizations, businesses, and individuals that are emitting greenhouse gases above their fair share of safe global emissions have obligations, duties, and responsibilities for the costs of adaptation or damages to those who are harmed are will be harmed by climate change.
7. Given the magnitude of potential harms from climate change, those who make skeptical arguments against the mainstream scientific view on climate change have a duty to submit skeptical arguments to peer-review, acknowledge what is not in dispute about climate change science and not only focus on what is unknown, refrain from making specious claims about mainstream science of climate change such as the entire scientific basis for climate change has been completely debunked, and assume the burden of proof to show that emissions of greenhouse gases are benign.
8. Those nations or entities that have historically far exceeded their fair of safe global emissions have some responsibility for their historic emissions. Although the date at which responsibility for historic emissions is triggered is a matter about which different ethical theories may disagree, at the very latest nations have responsibility for their historical emissions on the date that they were on notice that excess greenhouse gas emissions were dangerous for others, not on the date that danger was proven.
9. In determining what is any nation's fair share of safe global emissions, the nation must either assume that all humans have an equal right to use the atmosphere as a sink for greenhouse gases, or identify another allocation formula based upon morally relevant criteria. All nations have an ethical duty to explain why any deviation from per capita greenhouse gas emissions is ethically justified.
10. Some economic tools frequently used to evaluate public policy on climate change such as cost-benefit analysis that don't acknowledge responsibility for allocating the burdens for reducing the threat of climate change on the basis of distributive justice are ethically problematic.