Richard Alley’s splendid abilities as a communicator are well displayed in his new book Earth: The Operators’ Manual. Written as a companion book for a forthcoming PBS documentary he hosts, it provides a lively review of the science of climate change and of the renewable energy sources now able to be employed. The general reader who wants to understand why human activities are causing climate change and why it matters, and is prepared to put a little effort into the quest, will find the book an engaging explanation.
Alley begins with a dip into some history of how earlier generations depleted energy resources — the denuding of Pennsylvania of trees for fuel, the hunting of whales to near extinction for oil — and reminds the reader of how welcome the advent of fossil oil was to humanity, and to whales.
He is a frequent user of analogy, not always successfully he admits when describing his encounter with an animated congressman who was relaying the argument that because warming in the ice age cycles led to a rise in CO2 it follows that CO2 cannot cause warming because the effect always comes after the cause. The fictitious analogy Alley advanced was a credit card debt which ballooned over time as interest was added. On the congressman’s logic the interest charges could not have contributed to the debt because they started after the debt, so messages from the credit card company could be ignored. The analogy extends hilariously as Alley involves his accountant to track down the mystery of this growing debt, and the accountant even uses models to ensure that she isn’t missing anything. It was all rather wasted on the congressman who said he didn’t understand, but it’s one of the many homely comparisons Alley helps the reader with.
His descriptions and defence of modelling in climate science are illuminating. Our understanding of climate rests on fundamental science, and it is fundamental science that models implement to learn about the future and test themselves against the past. That test they pass with flying colours. But they are still models, as the scientists working with them fully understand, and Alley stresses that their results must be consonant with fundamental science, in agreement across a wide range of models, in accord with paleoclimate data from different research groups and different times, and supported by recent data of various types from various research groups. The sense of the science as the work of a wide community of scientists working across many fields is strong in his account.
The rock-weathering/CO2 thermostat is central in the book’s examination of Earth’s past climate. The CO2 coming out of volcanoes reacts with rocks to supply shell-making chemicals to the oceans. When the climate is cold that reaction is slow and the CO2 tends to stay in the atmosphere and warm the planet. In a warm climate the CO2 reacts more rapidly with the rocks, lowering the atmospheric load of CO2 and cooling the planet. Many things, from drifting continents to the evolution of life, have influenced climate, but CO2 has been critical. Alley leads the reader through many of the vast climate changes Earth has experienced and sees in all of them the clear fingerprints of CO2 which is necessary and sufficient to explain much of what happened. But the thermostat process nature provides is a slow one, and nature cannot undo the human-caused rapid increase in atmospheric CO2 fast enough to be of much use to us. We are heading for a much warmer planet.
Soccer as played by five-year-olds is another analogy Alley uses effectively. The players move in lurching clusters and it takes close watching to see an underlying order as one of the players in a team figures out what is happening before the rest do and that player’s kicks are resolutely in the right direction and take his lurching cluster towards one goal. Among the players contributing to the global warming of recent times CO2 is discerned as the big kicker, controlling the game. Human influences have become predominant over natural ones.
Recognising that the climategate affair is peripheral to the science Alley nevertheless feels it wise to make some comment on it, pointing out that all of five investigations found no evidence of malfeasance or anything that would weaken the fundamental results of climate science. He expresses some sympathy with scientists exasperated by ’crap criticism from the idiots’, having himself endured a call to his university president from a prominent alumnus to fire Alley for ’his crimes against the scientific community, Penn State University, the citizens of this great country and the citizens of the world’ — on the grounds that Alley’s own work on ice cores has confirmed that CO2 lags Earth’s temperature and therefore cannot be the cause of recent warming! Less subtle direct emails from others include remarks like ’You creep. I hope you suffer badly.’ The conclusion of his climategate and hockey stick discussion underlines the message that climate science has grown from a very substantial body of scientific work:
’Today, you cannot make evolution disappear by denying Darwin, nor relativity by erasing Einstein. Likewise, climate does not hang by the thread of the Climate Research Unit or a hockey stick.’
Alley is optimistically inclined, and while he acknowledges the potential seriousness of possible consequences of warming he doesn’t think the problem is too big to handle. The latter part of his book is given to coverage of all the alternatives to fossil fuel already available to us and how they add up to more than enough provision for the energy needed by humanity. As he prepared to enter this section of his discussion I was a little alarmed by the attention he was giving to economist William Nordhaus who has argued on economic grounds for acting later rather than sooner to address climate change. Why Nordhaus and not Nicholas Stern, who advocates much earlier and prompt action for economic as well as climate reasons, I wondered. But as the chapter progressed it became apparent that Alley was questioning the wisdom and the ethics of delay, and not accepting the adequacy of an economic theory which advocated waiting even though he had given it a sympathetic airing.
The careful survey he provides of sustainable energy sources and of energy conservation doesn’t cover new ground, but he often provides perceptive insights into some aspect of topic under discussion. The glow worms of New Zealand, for example, get a light without burning themselves up, a model of energy efficiency. Alley dwells on the far from insignificant energy savings to be had from compact fluorescent bulbs and light-emitting diodes (and I recalled with disgust the New Zealand energy minister’s reversal of a previous government’s decision to phase out incandescent bulbs).
Alley’s earlier book The Two-Mile Time Machine: Ice Cores, Abrupt Climate Change, and Our Future is a classic statement of what has been learned about past climate from the study of ice cores in which he has been deeply involved. I reviewed it here. It’s good to see him again offering a wide public an accessible entry into the science which is so critical for human civilisation. Alley is a registered Republican voter and an admirer of the great Abraham Lincoln for his advocacy of science. One hopes that memory might yet carry some weight with the current absurdly confident deniers among the party’s legislators.
Here’s a link to Richard Alley’s lively lecture to the 2009 AGU on carbon dioxide as the biggest control-knob in Earth’s climate history. There are many YouTube clips of him in action.