Kandel, with a background in astrophysics (astronomy at Harvard, astrophysics at the Paris-Meudon Observatory, presently emeritus senior scientist at the Ecole Polytechnique’s Laboratory of Dynamic Meteorology) and experience working with satellite monitoring of earth systems (radiation budgets, atmospheric interactions), tends towards a wide and fairly abstracted view.
The volume is full of large-scale quantifications: “the world’s streams and rivers contain only 2,000 cubic kilometers of freshwater (each cubic kilometer being a billion cubic meters or metric tons)”; the annual European freshwater runoff per capita is 4,600 cubic kilometers per year compared with 6,400 for Asia; “over the whole year, average solar radiant energy flux reaching the top of the atmosphere ranges from 140 W/m2 [watts per square meter] at the North Pole (150 at the South Pole) to more than 400 W/m2 at the equator”, etc.
At times these may seem illuminating, as for instance that “on average, the atmosphere contains the equivalent of a layer of 26 mm (a little over an inch) of water…”, or that the moisture of the entire biosphere has a similar equivalent depth of only 2 mm*, or even the unexplained assertion that water entering the North American Great Lakes can spend as much as 300 years before finding its way out the St. Lawrence (400 years for Lake Baikal before exiting through the Angara), but often, particularly in relation to current and near-term human water needs, the perspective seems only to reflect the cold distance of satellite observation and quantitative aggregation. Dr. Kandel’s French and Parisian digressions aside (this volume was originally published as Les Eaux du Ciel and translated into English by the author), his take can rather unrelentingly seem that of a remote and curious analyst, not an earth inhabitant – of any species.
Our experience and expertise are varied – and Dr. Kandel’s are evidently both extraordinary – and whether the approach here is simply governed by these or by a higher intent, I do not presume to argue with it, but as a water creature myself I found it routinely disorienting; only after completing the book did I realize that at least one of the multiple readings of its title had flown completely over my head.
Nonetheless Water from Heaven is a remarkable tour, from Big Bang to our star’s presumed eventual turn as a “red giant,” addressing along the way elemental and planetary formation; tectonic and tidal effects; the origins (and decimations) of biology; glacial pulses and Milankovitch cycles; atmospheric, oceanic and freshwater systems and their relations to soil and vegetative regimes; the rise of human civilization; water resource issues; water borne and sustained disease; the vagaries of anthropomorphic climate change, and a good deal more.
The volume frequently repeats facts or observations, sometimes usefully so, but often in a way suggesting it might have been composed in bursts, as perhaps to be expected from a busy working scientist. It is also illustrated with some two score uncredited diagrams, which though more or less intelligible, are not up to university press standards, although perhaps these are only weak substitutes for those of the original edition.
In the end I take Water from Heaven as a useful overview, but not a moving one. While the organization of elemental being – the stuff of stars, planets, moons, the churnings of the earth and its atmospheres – is a fundamentally worthy subject, from my current perspective water is primarily not a cosmic factor, but a biological one. I would welcome, even in passing, the overcoming of that distinction – the integration of the celestial and bodily, the upper and lower waters – as a highly valuable and presumably clarifying experience, but that did not much occur in my reading of Water from Heaven. The sea did not flow through my veins (even if a bit of the H2O in the interstellar medium did), I did not know my thought and speech as cloud and rain. I did however witness the record of the quantitative priesthood’s struggle, on a planetary scale no less, with their methods and understandings, and for that I am grateful.
*Both these depths presumably float on an idealized planetary sphere.