Over the past decade, Joshua Busby has become an important and prolific voice in the field of climate security. He contributed to the SIPRI’s influential Environment of Peace (2022) report, and he is the author of several high-profile articles on the issue. This is his first book on climate security.

An academic book such as this one can be judged against two parameters. First, is the argument a significant contribution that will influence the discipline? For short, is it field- or theory-guiding? Second, can it usefully inform policy-making discussions? In other words, is it action-guiding? I think that Busby broadly succeeds on both counts.

The aim of the book is to examine—anew—the security outcomes of climate change. Specifically, why do climate hazards (droughts, cyclones, and so on) lead to adverse security consequences (we might say, insecurities) in some states but not others, especially, in prima facie comparable cases? In a step away from the very early climate conflict literature, security outcomes or insecurities amount not only to conflict but also to emergencies that pose the risk of the large-scale loss of life. In that way, the author allows human security concerns to enter the picture.

The book consists of nine chapters including a general introduction and a conclusion. Chapter 3 is the most important one; in it, Busby advances the theoretical framework and method. Drawing on a wide range of literature, including scholarship on civil wars, ethnic conflict, vulnerability studies, development economics, and political science, Busby identifies three factors that play a role in a state’s general ability to deal with climate hazards: state capacity, which is defined as the ability to make and execute state policy; inclusion, which is ultimately a proxy for democracy in the absence of it and ranges from the representation of different groups to political legitimacy; and the availability and acceptance of international assistance.

In the three subsequent empirical chapters on drought and famine in Somalia and Ethiopia, drought in Syria and Lebanon, and cyclones in Myanmar and Bangladesh, Busby examines diverse security consequences in comparative cases of environmental/climate hazard by charting state capacity, state inclusiveness, and the role of international assistance. For example, in the case of Ethiopia, compared to itself over time and to Somalia, he shows that increased or improved state capacity ensured a better outcome to a comparable environmental/climate hazard. Overall, his findings affirm that “not every climate hazard leads to equally bad outcomes” (2). The takeaway is that we are not helpless when it comes to the security consequences of climate change: if state capacity is strengthened, including through international assistance, then disasters can be managed and, to an extent, mitigated.

The field of environmental and climate conflict is hugely contested. Scholars disagree not only on case selection but also on methods. Indeed, as Busby points out, the concept of drought itself is poorly defined, and no agreed-on definition exists. To my mind, Busby offers a refreshing way out of these impasses—not by siding with one view or the other but by acknowledging complexity and bringing other literatures to bear on climate conflict and security. His approach refocuses our view away from the particular to the generic—hence, to what really matters.

Regarding drought, for example, rather than obsessing whether one or other past drought was indeed caused by climate change, he argues that these droughts simply serve as proxies for future events. Thus, we know that climate change is likely to lead to more droughts. Therefore, the security consequences of drought are relevant to our understanding of what will happen under certain conditions.

Although Busby succeeds in offering a consolidated view of climate in/security, parts of the book seemed a little tedious to me. Rather than sticking to the traditional structure of theoretical chapters followed by empirical chapters, readers (and I hasten to suggest the writer) would have benefited from the structure adopted by Jan Selby, Gabrielle Daoust, and Clemens Hoffman in Divided Environments (Cambridge University Press, 2022): they dedicate each chapter to one issue (for the present book this would be state capacity, inclusiveness, and international assistance), invoking evidence from case studies as they go along. Such a structuring would have given greater prominence to the three factors and might have helped explain how they relate to each other. Specifically, it is unclear which is the most important factor for climate resilience (after all, some strong states are exclusive). This structure would have also required the author to be more consistent with definitions. As it stands, the meaning of state capacity shifts from a generic reading of the ability to enforce rules in chapter 3 to a more specific reading of the ability to manage disasters in the empirical chapters.

Busby is one of the few US scholars who has successfully bridged the gap between theory and practice, or else between academia and the world of practitioners (which is practically unheard of in the United Kingdom). From 2021–23, he served as a senior adviser for climate at the US Department of Defense. Although the book is written in a scholarly manner and represents his own views only, it is not surprising that Busby places great value on policy relevance. He makes three suggestions to practitioners. First, take the security implications of climate change seriously. To increase his chances of being heard by policy makers, he links human security to national security. Thus, practitioners ought to care about human security concerns because they can undermine national security; for example, when people protest a regime’s policy. Second, practitioners ought to focus on state capacity building. The case studies clearly show that states with relatively greater relevant state capacity—including, for example, early warning mechanisms—fared much better than those with decreased state capacity. Third, foreign aid and international assistance must be sensitive to issues of inclusion and exclusion. To perform these tasks, practitioners will need to be assisted by scholars. Climate security scholars of the future have a vital role to play in promoting relevant but not sensationalist messages on climate insecurity. They ought to provide maps and detailed country knowledge on where help is needed, what local specifics to observe, and the like. To my mind all this is unobjectionable.

What I do object to, however, is Busby’s claim that “climate change is an emergent structural parameter of international relations, as important, and perhaps ultimately more important, than anarchy in shaping the behavior of states going forward” (261). From where I stand, this is not only unnecessarily sensationalistic but also unsubstantiated by his list of examples. Many of these examples show not that climate change will replace anarchy but rather that climate change will exacerbate well-known security issues associated with and indeed resulting from anarchy, including cross-border migration, resource competition in the Arctic, and conflicts over water among neighbouring states.

Notwithstanding this criticism, States and Nature is a significant and timely contribution with real theory-, field-, and action-guiding potential.