Do persons have moral rights against the sort of harm that is expected to result from environmental problems like climate change, or are imperatives of environmental protection contingent upon their respective efficiency in promoting social welfare? If regarded as a rights issue, anthropogenic climate change would be subject to deontological constraints that trump considerations of costs; hence, cost–benefit analyses of environmental harm, which do not invest abatement efforts with this trumping power, are thus vulnerable to objections that resources spent on mitigation efforts might more effectively promote welfare if deployed elsewhere.

The question takes on additional importance as the “why” of normative justification for environmental protection drives the “what” of appropriate policy objectives and responses to its primary threats. Not only do approaches based in rights or justice lend more rhetorical urgency to such problems when compared to those based in welfare or utility—as the former posits a unique bad to be avoided at all costs, while the latter depends on a general good that can be promoted in various ways—but they tend also to justify significantly stronger commitments to environmental protection. Because rights and justice frames are more demanding, they have been more frequently invoked by scholars and activists on behalf of strong policy action on climate change. Such frames have also encountered resistance from powerful states, which are at least in principle more favorably inclined toward welfare-maximizing or efficiency imperatives.

These competing normative approaches to environmental protection are on display in these two important recent books, with Richard P. Hiskes grounding imperatives to avoid environmental degradation in human rights and intergenerational justice, and Eric A. Posner and David Weisbach doing so through a “welfarist” approach that might be termed Paretianism, since it requires Pareto improvement but not welfare-maximizing alternatives to the status quo if they make any party worse-off. Although neither works out in detail how extensive a set of environmental protections would be required by their approach, their contrasting stringency is suggested by Posner and Weisbach's justification for aiming to “balance” ethics and feasibility.

As the authors write in Climate Change Justice, justice-based approaches often “demand too much from the rich world” and so “threaten to derail a climate change agreement, thus hurting most of the nations and people who are pressing those very arguments” (pp. 4–5). The feasibility constraints built into their Paretianism are initially defended as pragmatic rather than ethical, designed to overcome political opposition rather than rectify philosophical shortcomings in alternative normative approaches, but later transform into a freestanding alternative to deontological or utilitarian ethics. Despite initially claiming Paretian outcomes to be “consistent with the requirements of justice” (p. 5), they later concede that there may be “no reason to think that the resulting outcome will be ethically ideal, or even close,” but that “there is strong reason to think the outcome will be better than the status quo” (p. 188). By contrast with Posner and Weisbach's pragmatically modest ambition, Hiskes claims in The Human Right to a Green Future that “environmentalism needs a new and more muscular political vocabulary grounded in today's central political ideals of human rights and justice,” claiming that environmental protection imperatives that are “rooted in these power words of contemporary politics … cannot be ignored in any election or by any government” (p. 2).

Both books are motivated by the conviction that stronger environmental protection measures are urgently needed and the judgment that normative principles can assist in their design. Hiskes invokes human rights as the “mechanism for intergenerational justice” (p. 6) that constitutes what he takes to be their proper end in protecting against “emergent” risks, where rights-based injunctions against transgenerational environmental harm also serve the salutary benefit of preventing environmental externalities within each generation. Posner and Weisbach likewise expect improved environmental outcomes to result from their “limited but important moral vision” of “states cooperatively advancing the well-being of their populations, and hence the global population, by agreeing to limits on greenhouse gas emissions” (p. 6).

In each case, their respective normative constructs drive the accounts of social change associated with each approach and underscore their practical and theoretical limits. Posner and Weisbach stipulate that powerful states will reject any climate treaty that opposes their national interests, while assuming that such realist premises leave room for at least some productive international treaty on climate change mitigation; as such, the authors articulate a more plausible path toward what would surely be a more modest treaty than is defended by approaches based in rights or justice. Hiskes essentially inverts this preference for political viability over philosophical appeal, convincingly arguing that environmental rights represent logical extensions of current human rights doctrine and require stringent action to safeguard the interests that such rights protect; yet, at the same time, he naively maintains that human rights and intergenerational justice discourses “cannot be ignored” during elections or by governments. Hiskes, and Posner and Weisbach, might thus be viewed as taking sides in the fundamental dispute about whether the perfect or the overly accommodating serves as the biggest obstacle to the good.

Posner and Weisbach's title is somewhat inapt, since the bulk of the book's content goes not to articulating a vision of climate justice but to criticizing alternative approaches based in either distributive or corrective justice, and they conclude that “justice does not have much to say about the design of the climate treaty” (p. 88). Curiously, their case against justice-based approaches rests primarily upon philosophical objections, rather than on the feasibility constraints in which they first frame their argument. The problem with applying distributive justice principles to a climate treaty, they suggest, is that egalitarian justice aims primarily to redistribute wealth, distracting from the core imperative of international climate policy, which should be to “reduce emissions as cheaply as possible” (p. 74). Ultimately, their rejection of distributive justice approaches turns on this specious characterization of current scholarship, combined with mention of “empirical evidence” demonstrating that climate change mitigation policy “is unlikely to be a good vehicle for redistribution” in that it is “badly targeted and expensive” (p. 75). Similarly, they dismiss applications of corrective justice principles by describing them as punitive rather than restorative, and suggesting that they rely upon conceptions of collective responsibility “that have been rejected by mainstream philosophers as well as institutions such as criminal and tort law” (p. 101). Given ample discussion of such issues elsewhere, such perfunctory and sweeping dismissals of existing climate justice work disappoint, particularly since they are unnecessary for advancing the authors' fundamentally practical thesis.

Nonetheless, Posner and Weisbach should be commended for their accessible prose, clear organization, and cogent analysis. Their aim is not to directly engage scholarly opponents in debate, and indeed they make reference to the burgeoning climate justice literature only in one footnote, never in the text. Rather, their objective is to construct a normative theory that takes seriously practical constraints on the development of international climate policy, and to consistently apply that theory to several divisive issues in climate change policy and politics on behalf of a reasonably strong climate change agreement. While the chapters on burden sharing offer less novel insight into normative issues that have been more thoroughly discussed elsewhere, the authors' strengths are on display in chapters on economic policy instruments and the question of discounting costs and benefits for future generations. Similarly, their attempt to join the ethical with the feasible represents an important challenge, if not an entirely successful response, to a scholarly literature that typically emphasizes one at the expense of the other.

By contrast, Hiskes employs a deontological framework that enjoins anthropogenic harm as a violation of human rights, regardless of mitigation costs. He situates his call for the expansion of existing human rights discourse to environmental protection within the scholarly literatures on human rights, identity, and global ethics, which are copiously engaged throughout. Building upon Tim Hayward's case for the legal instantiation of such rights in his Constitutional Environmental Rights (2005), Hiskes takes a more difficult tack than Hayward's relatively straightforward extension of individual security or subsistence rights to environmental harm, arguing instead for group rights of future generations that apply against current compatriots. Each of these departures from the conventional framework of human rights invites criticism and complicates his project; yet, by raising the level of difficulty, these departures also make his extensionist project more impressive and the surrounding discussion richer. He defends group rather than individual rights, since “future generations can be perceived ontologically only as groups because no specific persons yet exist” (p. 63), suggesting also that the duties associated with such rights might be borne through collective rather than individual forms of responsibility. Elsewhere, he formulates the “emergent” environmental rights as entailing a “collective duty owed by all of society to each individual person to protect his or her rights to clean air, water, and soil” (p. 46), identifying individual right holders but collective duty bearers. Whether positing group rights or collective correlative duties, Hiskes aptly draws upon recent scholarly literature defending both.

By attaching these group rights to future generations, the Hiskes approach runs headlong into Joel Feinberg's critique that nonexistent persons cannot be rights holders and Brian Barry's objection that obligations to future generations cannot be grounded in reciprocity, since future persons cannot reciprocate with present ones. In reply, Hiskes argues that current and future generations are bound together in a web of “reflexive reciprocity,” which holds that “respecting the rights of the future redounds to our benefit in a kind of virtual reciprocity—reflexively strengthening our rights today” (p. 49). Because environmental protection measures that we undertake today to safeguard future generations also protect the living against harmful pollution or ecological degradation, he suggests, this transgenerational relationship plays a role akin to reciprocity in effectuating intergenerational circumstances of justice. If this causal relationship holds, however, one might wonder why such contestable rights claims are necessary when the same actions would presumably be enjoined by individual rights of existing people. Finally, since this kind of reciprocity “exists only within cultures across their own generations” (p. 67), the environmental rights of future generations entail duties only for current compatriots, and persons now have rights-based environmental duties only to future conationals. Thus, Hiskes's theory provides no ground for claiming that persons now have obligations to living or future residents of nations most vulnerable to climate change, as climate justice imperatives require, even if it enjoins relevant harmful actions by others means.

Whether grounded in human rights discourse or welfare economics, imperatives to treat contemporary environmental problems as issues of basic justice among persons and peoples usefully remind readers of the nature and challenges of contemporary environmental politics. Sharing an ecological system that transcends borders and spans generations requires that we recognize our interdependence and aim to formulate policies to sustainably manage that system through terms that are fair to all and that recognize the interests and vulnerabilities of each. Both of these books demonstrate the potential value of scholarly analysis in seeking viable but normatively defensible resolution to protracted environmental conflicts, and acknowledge the responsibility of scholars to engage their conceptual tools and insight with the messy realities of the political world. Posner and Weisbach might be accused of conceding too much of the aspiration for global justice to realpolitik in their theoretical starting points, and Hiskes of not conceding enough to it in his, but the proper balance between philosophical elegance and practical applicability is bound to be elusive, and the effort to strike it is nonetheless advanced by work that rests of either side of the scale's pillar. Those interested in the creative tension between the demands of justice theory, the complexity of environmental problems, and the challenges of international politics will find much to consider in each of these works, which combine earnest desire for reasoned agreement and progressive change with keen insight and provocative policy prescriptions. While these are two quite different books, their divergent styles and premises concerning the politically possible complement each other, and together illustrate the rich theoretical landscape on which environmental politics is now contested.