Why Hydrogen? Planet, People and the Hydrogen Imperative
An outline for the perplexed
Humankind has already imposed deep changes on the earth, both in its appearance – forests into fields, fields into towns, watercourses into reservoirs, and so on – and in its functioning, so that the various throughputs handled until recently by nature alone – water, nitrogen, oxygen, phosphorus and above all carbon – are now following regimes highly modified by human hand. We are living with the ensuing disruptions, which for the most part are challengingly deleterious; in the eyes of a great many informed citizens it is now time to examine, comprehend and react to these changes, so as to forestall a dangerously damaged future, for our own sake, for the sake of our descendants, and for the sake of the planet upon which we will always depend.
Probably the severest of these impacts has been that of carbon dioxide – that invisible, odourless, relatively sparse constituent of the atmosphere, the prime nutrient of all plant life, terrestrial and marine, and the molecular actor which governs the earth’s “thermostat”. This is thus “one hell of a gas”. During the present (and ongoing) “Interglacial”, one of a suite of warmer periods which have regularly interrupted the generally icier climatological condition of the past few million years, the planet has run without severe thermal shock under an almost unvarying concentration in the atmosphere of 280 parts per million (ppm) of carbon dioxide.
The relatively benign climate resulting from this concentration constitutes the thermal background of humankind for the last ten thousand years – until now. The crucial stepchange, which began in earnest in the eighteenth century, is entirely due to our excavation from deep deposits in the earth’s crust of fossil carbon, buried by nature hundreds of million of years ago: coal, and more recently petroleum and natural gas. At the heart of these “resources” is the carbon atom, serviceable as fuel, yielding its energy in fiery combination with oxygen from the air, but also unavoidably exporting its by-product carbon dioxide into the atmosphere and ocean– thereby upsetting the planetary thermostat.
This carbon dioxide continues to be voided into the atmosphere, at the present rate of about 30 billion tonnes per year. By 2011 the concentration had reached 390 ppm, and matching temperature rises have been noted over large parts of the globe. The 390 ppm of the present, and the 280 ppm of our millennia-long pre-industrial past, should be contrasted with the level during the earth’s glacial periods: 180 ppm. The “natural swing” over millions of years has thus been between 180 and 280 ppm, yielding a parallel temperature swing of about 6 degrees C, shuttling between glacial and interglacial periods. We have imposed a sudden additional rise of 110 ppm on the higher level of CO2 concentration, and are beginning to perceive the consequences, not only in raw temperature, but in a range of impacts which severely threaten the biosphere and thus human welfare too.
Accompanying the impacts of carbon dioxide upon the atmosphere and life on land has been a suite of impacts upon the oceans, which cover over 70% of the earth’s surface: the predicted and already perceptible acidification of the upper layers of the world ocean, which may lead to the disruption, and indeed the destruction, of the whole marine food web; deoxygenation of many bodies of water, where varied forms of life will inevitably perish; a radically novel stratification of water bodies, impeding those diurnal and seasonal migrations essential to the complexities of the ocean food chain; and the sheer heating of surface waters to temperatures above the level of tolerance of corals and their resident life-forms. These are not “uncharted waters”: for example, the chemistry of the acidic carbon dioxide’s reaction with sea water has long been known.
Action is needed, for the ocean, for the climate and for the biosphere itself.