Breaking the silence about spring

Amy Seidl's new book, Early Spring, describes the impacts of climate change on the world immediately around us.

From RealClimate, part of the Guardian Environment Network
guardian.co.uk, Tuesday 14 April 2009 15.54 BST

Did you know that in 1965 the U.S. Department of Agriculture planted a particular variety of lilac in more than seventy locations around the U.S. Northeast, to detect the onset of spring — in turn to be used to determine the appropriate timing of corn planting and the like? The records the USDA have kept show that those same lilacs are blooming as much as two weeks earlier than they did in 1965. April has, in a very real sense, become May. This is one of the interesting facts that you'll read about in Amy Seidl's book, Early Spring, a hot-off-the-press essay about the impacts of climate change on the world immediately around us – the forest, the birds, the butterflies in our backyards.
The brilliant title of Seidl's book was one of the reasons that it caught my attention. The other was that I have realized I need to better educate myself about the impact of climate change on everyday life. I've been dismissive of the idea that the average person can really detect the impacts of recent warming on, for example, the timing of the apple-blossom season, but I've been taken to task by several of RealClimate's readers for this. If you are paying attention, they have argued, the changes are actually rather obvious.
Of course, Amy Seidl is not the average person. Rather, she's a trained ecologist with a Ph.D. (as well as an avid gardener) and she's clearly paying extremely close attention. Her book is the first one I have read that effectively brings home the tangible impacts that global warming will have – is having – on our everyday lives. "We are increasingly familiar," she writes, of images of melting glaciers, "but how do we give them relevance in our lives? From my window I see no glaciers." She answers her own question with a series of vignettes, some from her own experiences, many more from her extensive research (well referenced throughout the book).
Cardinals, robins and cowbirds are all arriving earlier in Vermont than they did a century ago. Kingfishes, fox sparrows and towhees are not. Why the difference? The answer, as Seidl explains, is that the former group has the ability to respond ecologically to the changes, because these birds cue their arrival to temperature. The latter, it appears, respond more directly to temporal cues, that won't change even as climate does. It's obvious from this example that the make up of bird life in Vermont – the species distribution – will change over time. This may not necessarily be a bad thing of course. On the other hand, it turns out that the robins are the most important host for West Nile virus; the early bird gets the worm, so to speak, and passes it along to humans.
Maple seedlings need about 100 days of below-freezing weather. As this becomes rarer, fewer maples will populate the forests. This, Seidl explains, is why species-range models predict the decline and eventual loss of sugar maple (at least in New England) in the future. But, she notes, the models don't take into account the full complexity of the system, such as the impact of competition among different species. So we don't really know what will happen, or how fast. What we do know is that maple-sugar farmers have noticed – and documented – an earlier maple sugaring season over the last few decades.
There are many other examples in Early Spring both of clear climate-related changes (such as the early arrival of robins), and of less clear-cut changes (the maple sugaring season). Seidl doesn't make the common mistake of assuming that the more ambiguous examples are necessarily due to climate change. For example, she quotes a maple-sugarer who points out that technological changes have allowed them to tap maples earlier, and hence that the timing of sugaring is a weak measure of climate change. The point though, is that even rather minor changes are, after all, being noticed. And if much larger changes do occur, as predicted, they will most certainly have impacts we can't ignore, even if we don't live in the Arctic or in Bangladesh. In other words, Seidl tells us, listen to the farmers and gardeners, and the observations of regular people: they are meaningful.
The soberness of Seidl's approach to the subject of climate change impacts contrasts starkly with that of many books before it. It couldn't be further, for example, from Mark Lynas's book, Six Degrees, which is a truly alarming read. In my comments on Six Degrees, I said that it wasn't an alarmist book. I stand by that characterization, because – and this is what I liked about it – it doesn't go beyond what is in the scientific literature. However, while Lynas's book is a straightforward reading of the scientific literature, it is a somewhat uncritical one, and hence tends to emphasize what might happen in the future over what will happen; this is a point that many readers of my review seem to have missed. Seidl's book, on the other hand, is focused on the more certain – and often less dramatic — things, and on the impacts we are likely to see in our own lifetimes.
The calm demeanor of Seidl's book, and the very personal nature of it, could lead one to think that it is primarily just a philosophical reflection on the climate change story. Indeed, Bill McKibben, in his introduction to Early Spring, says that in the face of changes we may not be able to prevent, "one of our tasks is simply to bear witness". Certainly, the book is partly that. But Seidl's voice, like Rachel Carson's before her, has the authentic and authoritative voice of a scientist, made all the more compelling for being very much rooted in the author's own story and experiences. And she doesn't pull punches when she has something definitive to say: "One thing is clear:" she writes, "we will not be able to manage the climate".
Early Spring has the potential to be immensely influential, a real turning point in the popular appreciation of climate change impacts among laypersons and scientists alike. Read it.