COP30 in Belém in the Brazilian Amazon was in many respects a profoundly moving and uplifting event, in which Indigenous people protested for their rights, the Brazilian government launched an ambitious new tropical forests fund, and at least 80 countries signalled their desire to work together to speed up the transition to renewable energy. But it was also a deeply disappointing COP. A number of the major fossil fuel economies clubbed together to undermine the global commitment made at COP28 to transition away from these fuels. Absent US leadership, Russia, Saudi Arabia and a few other countries were given free rein to work in this way, such that the conclusion of COP30 felt at best bittersweet.

One area that did experience progress was adaptation and resilience, with the COP seeing an agreement from all countries present to at least triple global adaptation finance by 2035, as well as a commitment to track progress towards the global goal on adaptation. Whatever the world eventually achieves in reducing greenhouse gas emissions, it is abundantly clear that we all need to move fast – and with skill, intellect, solidarity and agility – to adapt to the changes to the climate already under way, let alone to the much more severe changes that are almost certain now to follow.

Susannah Fisher’s profoundly illuminating, comprehensive and ultimately hopeful new book on adaptation, Sink or Swim, could not therefore be more timely or relevant. Of much that has been written, I would venture to say this is the single most effective, well-structured and balanced introduction to this pressing issue that I have read. It also feels strikingly up to date – no mean feat, given the pace at which the climate is changing and its impacts are made visible.

The book begins by setting the scene and situating the reader in Fisher’s own experience of circa 20 years of engagement on adaptation as an academic and researcher, including time spent with communities at the frontline of a changing climate. The first three chapters provide an insight into the latest science, a potted history of the effort to pursue adaptation so far, and the “narrow window of opportunity” that we now face for greater, faster action equal to the scale of the challenge.

Chapter 4 sets out some of the issues posed by “people on the move”, surely one of the most profound of all challenges of a world in which the climate has spiralled out of control. The next chapter describes the impacts on the global food system of a changing climate. Chapter 6 gives an insight into the role Nature can and must play in helping us to adapt, and how it will itself be affected by a changing climate. Chapter 7 addresses the issues of fragility and conflict, which are so closely linked to the changing climate. This includes a fascinating discussion of how the world’s militaries are thinking about the issues, and the role they might play in the future, both for good and in some instances for ill, as the climate becomes more severe.

Throughout the book, Fisher helpfully includes sets of choices and lists of difficult questions that need answering. She paints a picture of the best- and worst-case scenarios for each of the issues she describes – for example, perfectly plausible visions of global decisions and conversations in the 2040s, in which we have either reached a collaborative, effective way of addressing the issues, or where dystopia prevails. Chapters 8 and 9 – followed by an epilogue that finds “glimpses of hope” – set out what needs to happen. The onus is on communities, societies and political leaders to work towards solutions in a spirit of collaboration and a clear sense of our responsibilities to one another and our sheer interdependence.

I finished the book simultaneously feeling more worried about the future and more determined to act, as well as more hopeful that we do now know so much of what needs to be done, with so many lessons to be learned from how countries such as Bangladesh have led major and effective national efforts over the past two decades. We must, and we will, adapt.

Sink or Swim: How the World Needs to Adapt to a Changing Climate by Susannah Fisher. Bloomsbury Sigma, 2025. ISBN: 9781399414050

Edward Davey is head of the World Resources Institute’s UK office.