These climate science primers have been written by specialists "for a scientifically literate audience": they will be useful for lay readers, for university students, and for scientists in other fields or even other areas of climate science. The series is notable for the breadth of topics it covers, but the individual volumes are mostly quite focused and achieve some depth: as well as explanations of the core concepts and broad features of particular domains, some of them are effectively summaries of the latest research, covering current debates and uncertainties.

Some of the volumes treat material that is fairly well covered elsewhere. Because it is central to understanding global warming, The Global Carbon Cycle traverses ground well trodden by popular science, but Archer's explanation here, emphasizing the three different time scales of carbon dioxide cycling and treating methane separately, is pedagogically rather elegant. Any introductory atmospheric physics text would cover most of Atmosphere, Clouds, and Climate, but the latter is accessible to a broader audience. Randall also gives exceptionally clear explanations of phenomena such as turbulent mixing, cumulus instability (thunderstorms) and baroclinic waves, as well as throwing in a look at predictability and interactions with the broader earth system.

Planetary Climates surveys the planets and major moons one by one, covering their histories as well as current states and using them as case studies to introduce some general theory. And Paleoclimate proceeds chronologically through different eras, from the Faint Young Sun problem and Snowball Earth scenarios down to the much more rapid, but better resolved, changes of the ice ages and the Holocene. As up to date summaries of topics that are under active research, these volumes are likely to offer something new for almost everyone.

Vallis is a specialist on ocean dynamics and Climate and the Oceans has nothing on acidification or ocean chemistry, but rather covers circulation patterns, heat storage and transport, and the ocean's role in climate variability and global warming. Western boundary currents, the overturning circulation, and the North Atlantic Oscillation and El Niño events are examined in some detail.

In Climate and Ecosystems Schimel mostly takes a high level perspective, looking first at climate controls on ecosystems, through water, energy and nutrient constraints, and then at ecosystem feedbacks on climate. Here, along with broad carbon fluxes, he considers topics such as the Amazon "recycling" hypothesis, the CLAW hypothesis for phytoplankton feedback on temperatures via dimethylsulfide and aerosols, and the methane cycle. He also surveys the challenges of modeling the future and incorporating ecosystems into earth system models.

The Cryosphere surveys seasonal snow and freshwater ice, sea ice, glaciers and ice-sheets, and permafrost, going into details often neglected in general climate science texts, before stepping back for an overview of general cryosphere-climate processes and the role of the cryosphere in climate change.

Some material is inevitably repeated between volumes. Several introduce basic radiative energy models, several explain circulation patterns driven by the Coriolis effect, and there are multiple explanations of the El Niño effect. But this has been kept to a minimum. The implications of human greenhouse gas emissions are major topics in several of the volumes, but the authors avoid recapitulating general concerns about global warming or attempting to address pseudoscience, with only Vallis in Climate and the Oceans digressing from his core subject to rebut some common misrepresentations of the science.

The Princeton Primers fill a gap between popular works, general climate science textbooks, and the full wealth of the scientific literature. Someone with solid high school physics, mathematics, and chemistry should be able to get through most of them, but the presentations, while simple and clear, are brisk, without repetition or digressions into biography and the history of science, and the seven volumes of the series so far fit in a lot. They are not textbooks and there are no tutorial exercises, but they are not just descriptive either, making some attempt to teach key methods and tools.

In several of the volumes, more technical matter is treated in separate boxes within the text. This works quite well except in Planetary Climates, where a chapter on Venus contains fourteen separate boxes, between them presenting a completely general one-dimensional convective-radiative model and an introduction to atmospheric energy transport, and a chapter on Jupiter has nine boxes on rotational dynamics; these are scattered and awkwardly linked to the main text. Other volumes push technical material to appendices or to the ends of chapters, while The Cryosphere begins with two chapters on the material properties and thermodynamics of snow and ice.

Full references are provided, often extending to very recent work, but almost all the volumes make some effort to be more useful for non-specialists. Most have shorter "further reading" suggestions, sometimes annotated; Paleoclimate includes separate references at the end of each chapter, with recommended items marked; and in Climate and Ecosystems select items in the references are in bold, offering a "personal best-of list ... good entry points to the extensive primary literature". All the volumes also have glossaries and indices.

The series has room to grow, even allowing for forthcoming volumes on Natural Climate Change, The Sun's Influence on Climate, Abrupt Climate Change, and Terrestrial Hydrology and the Climate System. Perhaps the most obvious lacunae are volumes on aerosols, on climate modeling — possibly even separate ones on circulation and earth system models — and on climate data, covering collection, assimilation, analysis, reanalysis and so forth.

If physics was the most exciting science of the first half of the twentieth century and molecular biology of the second half, climate science must be a candidate for the current half-century. Certainly anyone with any general scientific curiosity will want to know something about it, and this series is well pitched for those who want to go beyond popular works, especially as it makes it easy to focus on topics of particular interest.

December 2014