Andrew Weaver is a notable Canadian climate scientist. He’s recently written a short book for the general reader to give an easily understandable account of the science of human-caused climate change, to explain its impacts and to suggest solutions. The book is published as one of the Rapid Reads series in Raven Books. It’s titled Generation Us: The Challenge of Global Warming – and if you’re wondering what the title means, it’s a contrast with Generation Me and signifies the moral dimension of tackling climate change.
His account of the science is straightforward. He explains the natural volcanic sources of carbon dioxide and points out that human activities are emitting between 100 and 200 times the amount released by volcanoes and at a very rapid rate. Tens of millions of years of storage of carbon dioxide in coal, oil and natural gas is being returned to the atmosphere in a few decades.
Weaver is a climate modeler, and he includes an illuminating brief account of the ways climate models work, imagining a scaled replica of Earth, its ocean and its atmosphere, made from Lego bricks, with the exchanges between the adjoining bricks represented by millions of equations. He stresses the importance of testing models against observed twentieth-century climate, and explains how they show that natural variability is incapable of explaining the late twentieth-century warming.
Current warming, warming still in the pipeline, sea level rise, changing patterns of precipitation and the likelihood of mass ecological extinctions are carefully described as consequences of the rise in greenhouse gases. Species extinction is high on the list of his concerns and he spells out the percentages relative to the temperature rise we allow.
Moving on to the question Why Should I Care? Weaver suggests that it boils down to the extent to which we feel responsibility for future generations. In speaking of the consequences as future he seems to be addressing a mainly North American audience for whom the questions can still seem abstract, though he does mention African and Alaskan and Island populations which are already experiencing the results of warming. He acknowledges the difficulty for politicians elected for short terms in facing a problem for the solution of which there is no immediate benefit, and applies the theme of the tragedy of the commons. However he quietly but firmly sets out the scale of the dangers ahead, including tipping points which lead to irreversible change.
Assuming we agree that we have responsibility for the well-being of future generations Weaver moves to the question of what we can do about it, which includes at least a measure of adaptation. Technological solutions are readily available, but they are costly. Hence the supreme importance of putting a price on greenhouse gas emissions, enabling the new energy technologies to compete and to drive down their prices as they become commonplace. He discusses the relative merits of caps and taxes.
How can we meet the 2 degree threshold of warming which the Copenhagen Accord affirmed? If we want a 90 percent chance of staying below 2 degrees we can now put only a further 249 billion tonnes of carbon dioxide into the atmosphere. That allows less than 7 years at current levels of emissions before reducing to zero. Clearly that isn’t going to happen so he suggests accepting a 66 percent chance of staying below 2 degrees. That gives us more wiggle room in that we could add a further 1790 billion tonnes, or 49 years at current rates followed by zero. If we immediately started slowly reducing current rates of emissions we could allow ourselves around 98 years before the final step to zero.
Behavioral solutions begin with voting. Declining voter turnouts in Canada and the US don’t bode well, especially as they reflect a very low level of youth voting. He comments pointedly that the generation which is going to see the clearer manifestation of global warming is not showing up at the ballot box. Get out and vote, he says, and then mobilize support for the measures you want your elected representatives to take. And look at your own behavior. Ask yourselves how your individual actions are affecting the livelihood of others. Embrace change creatively.
Weaver’s writing is restrained. There is not a trace of overstatement. His book is an appeal to the intelligence, and the ethical imperative which underlies it is offered, not demanded. Reasonable man though he is he has nevertheless in recent years come in for his share of savage attack from deniers. He has famously come out fighting in defense of his science and his integrity. The story of his suit against the National Post newspaper can be followed on DeSmogBlog, as can the more recent suit against Canadian climate change denier Tim Ball.
His engagement with the public is not confined to writing books. This lively presentation in a short Greenpeace video sounds some of the leading themes of the book.
