1 See, for instance, German Advisory Council on Global Change (WBGU), The Future Oceans—Warming Up, Rising High, Turning Sour (Berlin: WBGU, 2006), p. 110; and Hansen, James, “Scientific Reticence and Sea Level Rise,” Environmental Research Letters 2 (April–June 2001), pp. 1–6.Google Scholar

2 Brown, Oli, “The Numbers Game,” Forced Migration Review 31 (October 2008), p. 8.Google Scholar See also note 5 below.

3 More than a tenth of humanity resides in vulnerable regions of the world that are within ten meters of today's sea level, also known as Low Elevation Coastal Zones (LECZ). They encompass two-thirds of urban settlements with populations greater than 5 million in addition to a disproportionate number of small island nations and least-developed countries. For an example of the dynamics of human response to sea-level rise, see Sheila Gibbons and Robert Nicholls, “Island Abandonment and Sea-Level Rise: An Historical Analog from the Chesapeake Bay, USA,” Global Environmental Change 16, no. 1 (February 2006), pp. 40–47.

4 Delta Committee, Working Together with Water: A Living Land Builds for Its Future (Deltacommissie, 2008); available at www.deltacommissie.com/en/advies. See also Tol, Richard, “Estimates of the Damage Costs of Climate Change. Part 1: Benchmark Estimates,” Environmental and Resource Economics 21, no. 1 (January 2002), pp. 47–73.CrossRefGoogle Scholar

5 See Risse, Mathias, “The Right to Relocation: Disappearing Island Nations and Common Ownership of the Earth,” Ethics & International Affairs 23, no. 3 (Fall 2009), pp. 281–300.CrossRefGoogle Scholar Risse argues, on the basis of collective and egalitarian stewardship of the earth, that the people of Kiribati have the right to relocate to any country. His analysis is complementary to, though distinct from, ours, which does not draw upon cosmopolitan reasoning. A robust debate on the very category of environmental refugees has endured for nearly a decade, since Richard Black challenged Norman Myers's position that there were at least 25 million environmental refugees in the mid-1990s in addition to the then 22 million refugees as officially defined. See Norman Myers, “Environmental Refugees,” Population and Environment 19, no. 2 (November 1997), pp. 167–82; and Richard Black, “Environmental Refugees: Myth or Reality?” Working Paper No. 34, New Issues in Refugee Research, UNHCR, ISSN 1020-7473. Black argues that the actual link between environmental harm and refugee flows is tenuous at best, although recent work, such as that of Oli Brown and Koko Warner and others, has established the connection more convincingly, especially in the case of climate change. See Oli Brown, “Climate Change and Forced Migration: Observations, Projections and Implications,” Background Paper for the 2007 Human Development Report; and Koko Warner et al., “In Search of Shelter: Mapping the Effects of Climate Change on Human Migration and Displacement,” Cooperative for Assistance and Relief Everywhere, Inc. (CARE), 2009. On the legal and political dimensions, with emphasis on climate migrants affected by sea-level rise in particular, see Selma Oliver, “A New Challenge to International Law: The Disappearance of the Entire Territory of a State,” International Journal on Minority and Group Rights 16, no. 2, 2009, pp. 209–43; Jon Barnett and Michael Webber, “Accommodating Migration to Promote Adaptation to Climate Change” (Stockholm: Commission on Climate Change and Development, 2009); and Frank Biermann and Ingrid Boas, “Preparing for a Warmer World: Towards a Global Governance System to Protect Climate Refugees,” Global Environmental Politics 10, no. 1 (February 2010), pp. 60–88.

6 Byravan, Sujatha and Rajan, Sudhir Chella, “Providing New Homes for Climate Change Exiles,” Climate Policy 6 (2006), pp. 247–52.CrossRefGoogle Scholar See also Sujatha Byravan and Sudhir Chella Rajan, “Warming up to Immigrants: A New Option for US Climate Policy,” Economic and Political Weekly 44, no. 45 (November 2009), pp. 19–23.

7 The international agreement could be a protocol under the Refugee Convention or the UNFCCC or on the basis of a new treaty altogether. Most experts do not want to change existing treaties under the Refugee Convention, since that would jeopardize an international agreement that has been forged with great difficulty to protect the rights of political refugees.

8 Another reason to be prepared is that military analysts worry that sudden mass migration will increase the likelihood of conflict or war. “Although climate change may force migrations of workers due to economic conditions, the greatest concern will be movement of asylum seekers and refugees who due to ecological devastation become settlers.” CNA Corporation, National Security and the Threat of Climate Change (Alexandria, Va.: CNA Corp., 2007), p. 16.

9 Tremmel, Joerg, ed., Handbook of Intergenerational Justice (Cheltenham, UK: Edward Elgar, 2006), p. 7.CrossRefGoogle Scholar

10 All the data is taken from cait.wri.org for 2005 and include emissions associated with land use changes and forestry. The appropriate comparison should of course be with cumulative emissions, but it so happens that even current emissions are vastly disparate between rich and poor countries.

11 Agarwal, Anil et al. , Green Politics (New Delhi: Centre for Science and Environment, 1999).Google Scholar See also Henry Shue, “Subsistence Emissions and Luxury Emissions,” Law & Policy 15, no. 1 (January 1993), pp. 39–60. Fuelwood cookstoves in particular are associated with the emission of black carbon, which is very short-lived in the atmosphere but is estimated to have a substantial radiative forcing effect. We do not consider such emissions in our analysis for several reasons: one, because they are indeed subsistence emissions, as we have noted above; two, because they do not accumulate in the atmosphere and therefore do not cause delayed effects; and, three, because the science on their actual radiative forcing impact is still in question, as noted most recently by Kristin Aunan et al., “Radiative Forcing from Household Fuel Burning in Asia,” Atmospheric Environment 43, no. 35 (November 2009), pp. 5674–81.

12 Global average temperatures have risen by about 0.8 degrees Celsius since preindustrial times, and given thermal inertia of the atmosphere, current concentrations could well cause another degree of warming. In this context, there is widespread acknowledgment that even at present levels, greenhouse gases in the atmosphere will cause “unacceptable” harm; but there is nevertheless a great deal of analysis to find ways to limit future emissions rapidly enough to limit warming to about 2 degrees Celsius. See German Advisory Council on Global Climate Change (WBGU), Solving the Climate Dilemma: The Budget Approach (Berlin: WBGU, 2009).

13 A simplified first-order approximation is:

where C is the carbon dioxide concentration in parts per million by volume in any given year and Co is the reference concentration, which we can take for this argument to be preindustrial levels of 280 parts per million. ΔF is the change in radiative forcing in watts per square meter and expresses the additional warming caused by the extra carbon dioxide in the atmosphere.

14 See, for instance, Parfit, Derek, Reasons and Persons (New York: Oxford University Press, 1984)Google Scholar; and Ernest Partridge, “On the Rights of Future Generations,” in Donald Scherer, ed., Upstream/Downstream: Issues in Environmental Ethics (Philadelphia: Temple University Press, 1993), pp. 40–66.

15 See Intergovernmental Panel on Climate Change, “Summary for Policymakers,” in Climate Change 2007: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge: Cambridge University Press, 2007), pp. 7–22. For the disproportionate impacts of sea-level rise in particular, see McGranahan, Gordon et al. , “The Rising Tide: Assessing the Risks of Climate Change and Human Settlements in Low Elevation Coastal Zones,” Environment & Urbanization 19, no. 1 (November 2007), pp. 17–37.CrossRefGoogle Scholar

16 No doubt, many of the world's wealthy regions also face significant vulnerabilities from climate change. Indeed, low-lying regions are also found in developed nations, such as the Netherlands, the United States, and Japan. Nevertheless, weather-related disasters are experienced in substantially different ways by poor and rich regions having similar vulnerabilities. For instance, while the southeastern United States faces weather-related risks comparable to Central America and the Caribbean, far greater numbers of people are affected in the latter region. In terms of financial damage, however, the picture is reversed. Thus, the United States experiences financial damage from these disasters that is usually many times larger, reflecting its greater levels of physical development, higher valuations, and, by implication, more secure infrastructure for protecting human health and livelihoods. See, for instance, www.em-dat.net.

17 See, for instance, Shue, Henry, “Global Environment and International Inequality,” International Affairs 75, no. 3 (July 1999), pp. 531–45CrossRefGoogle Scholar; Stephen Gardiner, “Ethics and Global Climate Change,” Ethics 114, no. 3 (April 2004), pp. 555–600; and Steve Vanderheiden, Atmospheric Justice: A Political Theory of Climate Change (New York: Oxford University Press, 2008).

18 Shue, “Global Environment and International Equality,” p. 535.

19 Vanderheiden, Atmospheric Justice, p. 190.

20 Ibid., p. 192.

21 For instance, the United States, EU-25, Russia, China, Japan, and India remain in the same relative positions as the top cumulative emitters in both cases. In terms of global fractions, only the EU-25 drops significantly from about 27 percent to 18 percent in the shift of the base year from 1850 to 1990, while China rises from about 7 percent to 13 percent. The United States remains in first place, but its contribution to total emissions reduces from about 30 percent to 23 percent. See also Vanderheiden, Atmospheric Justice, pp. 190, 213; and Baer, Paul, “Adaptation: Who Pays Whom,” in Neil Adger et al., eds., Fairness in Adaptation to Climate Change (Cambridge, Mass.: MIT Press, 2006), pp. 131–54.Google Scholar

22 One way to stipulate this is that there have been equal per capita emissions across the globe and throughout history.

23 More precisely, as Thomas Pogge has suggested, these might be considered “intermediate duties”—that is, duties to avert harms that one's past conduct may cause in the future. If some harm is inevitable, then one has a duty to make amends so as to mitigate its impacts in the future. Pogge, Thomas, “World Poverty and Human Rights,” Ethics & International Affairs 19, no. 1 (Spring 2005), pp. 1–7.CrossRefGoogle Scholar

24 As Amartya Sen suggests in his definition, a functioning is “an achievement of a person, what he or she manages to do or be. It has to be distinguished from the commodities that are used to achieve those functionings.” Sen, Amartya, Commodities and Capabilities (New York: Oxford University Press, 1987), p. 7.Google Scholar Yet, the achievement of functionings is certainly tied to the state's ability to mobilize resources—infrastructure, goods, and services—for its people. While the state will of course be short of these even in less than extreme cases, it may still be able to act on behalf of the EV and attempt to acquire them until and unless it is itself hampered from doing so.

25 The question of compensation for cases where this threshold has not been crossed should not generally arise under proportionate accumulation, but can arguably be relevant under disproportionate accumulation. We do not discuss this situation here, but see Shue's case for doing so in “Global Environment and International Inequality” and Simon Caney's counterarguments in “Cosmopolitan Justice, Responsibility, and Global Climate Change,” Leiden Journal of International Law 18, no. 4 (2005), pp. 747–75.

26 The disappearance of land in many of the most vulnerable countries will result in the impossibility for their states to continue functioning given of the high density of population in delta regions, the high fraction of income accruing from them, and the high proportion of land that these areas represent. As an illustration, in Bangladesh, where some 70 million people live and work along the rugged deltaic coastline, hurricanes, coastal surges, and saltwater inundation into vast areas of the country have already affected livelihoods and destroyed many villages and lives. In the last thirty years alone, some thirty square miles of the Sundarbans, a complex network of tidal waterways, mudflats, and small islands of mangrove forests in the river delta of the Ganges, have vanished entirely. In 2000, 45 percent of the population lived in the ten-meter LECZ, which also comprised nearly half of the total land area. In comparison, about 6 percent of India's population in 2000 (roughly equaling Bangladesh's vulnerable population) lived in the ten-meter LECZ, occupying 6 percent of the total land area. The Bangladeshi state clearly is far more likely to face collapse and long-term immobilization than is India.

27 Intergovernmental Panel on Climate Change, Climate Change 2007: Synthesis Report. Summary for Policymakers (Cambridge: Cambridge University Press, 2007), p. 11.Google Scholar

28 Forced migration can result from several direct and indirect factors, and SLR associated with climate change is one among these. Nevertheless, SLR can be attributed with relative clarity to climate change, even though land subsidence or siltation can confound the causative factors. In cases of drought, desertification, changes in food production, and increases in death and disease burden associated with heat waves and vectors, there are many other human-induced as well as natural factors of influence apart from climate change.

29 Edward Page, “Distributing the Burdens of Climate Change,” Environmental Politics 17, no. 4 (August 2008), pp. 556–75. The Association of Small Island States (AOSIS) has drawn up an insurance proposal along these lines; see AOSIS, “Multi-Window Mechanism to Address Loss and Damage from Climate Change Impacts,” Proposal to the Ad-hoc Working Group on Long-term Cooperative Action of the United Nations Framework Convention on Climate Change; available at unfccc.int/files/kyoto_protocol/application/pdf/aosisinsurance061208.pdf.

30 See Vanderheiden, , Atmospheric Justice, pp. 143–80.Google Scholar

31 Evidence for this argument can be found, for instance, in Carl Trocki, Opium, Empire and the Global Political Economy: A Study of the Asian Opium Trade, 1750–1950 (London: Routledge, 1999); and in Prasannan Parthasarathi, Why Europe Grew Rich and Asia Did Not (Cambridge: Cambridge University Press, forthcoming).

32 Shue, in “Global Environment and International Inequality,” makes this case quite compellingly. As he points out, the difference between being born in 1975 in Belgium as opposed to Bangladesh is in large part associated with the difference in accumulated benefits of economic activity in the two countries going all the way back to the Industrial Revolution. Childhood nutrition, educational opportunities, and lifelong standards of living are likely to differ enormously precisely because current generations are, and future generations will likely be, the differential beneficiaries of earlier industrial activity.

33 For a useful summary of the legal and ethical considerations concerning reparations, see Posner, Eric and Vermeule, Adrian, “Reparations for Slavery and Other Historical Injustices,” Columbia Law Review 103, no. 3 (April 2003), p. 689.CrossRefGoogle Scholar Reparations for historical malefactions are not as unusual as some may believe. In 1988, the U.S. Congress passed the Civil Liberties Act, which explicitly recognized that “a grave injustice was done to both citizens and permanent residents of Japanese ancestry by the evacuation, relocation, and internment of civilians during World War II.” The act issued an apology, set up a public education fund to finance efforts to inform the public about the internment, and provided survivors a symbolic payment of $20,000 each. Further back in history, many Native American tribes have received compensation for lands that were ceded to the United States by various treaties. Other countries have also paid reparations for past grievances. In 1952, the West German government began paying Israel 3 billion deutsche marks for slave labor and the persecution of Jews during the Holocaust, as well as for confiscation of property. The state of Israel was paid on behalf of victims who were no longer alive or had no surviving family.

34 Climate exiles will truly have lost everything; and the right to start anew in another country, while a welcome rescue, might not even be what they desire. They may wish that their homes had never been destroyed in the first place; and a few may even decide not to leave their homes until long after conditions have turned intolerable, but that can hardly be an argument to deny them the right to immigrate.