The news continues to flow in about the collapse of this year's sockeye salmon runs. Whether this is a one year phenomena or a portent of the continued decline of this once great stock only time will tell, but it does have that same sickening feeling to it that I remember from being in Newfoundland as the cod stocks collapsed. Twenty years later and there is still no sign that that fishery will ever supply anything other than a modest recreational fishery.
The collapse of the salmon stock though is another example of how hard it will be to recognize the potential effects of global warming. For those of us who believe that the broad scientific consensus that there is such a thing as human caused (or contributed to) global warming and that there will be a series of environmental effects that will be triggered by that, the collapse of the salmon stock is not particularly surprising. Salmon like cooler waters and suffer higher mortality before spawning and higher mortality when migrating to the ocean when waters are warm. But the fact of the matter is that it is impossible to chalk the collapse up to that cause alone; overfishing, habitat degradation and parasites combined with global warming (together with whatever poorly understood natural factors may be at play) all contribute to the decline. Crying 'global warming, global warming' invites the crying wolf problem because of the complexity of the issue.
But even in British Columbia we can look across the entire landscape and see the evidence that something is changing on a widescale and the common element appears to be climate. The struggles of the salmon stocks have become more pronounced each year. Yes there have been good years, but even in those good years the runs have been less predictable in their behaviour and less consistent with their history. Fishing has been more tightly controlled and, at least on a local level, greater efforts have been made to protect or restore fish habitat. Despite this something is changing and it seems to be changing on a broad scale across many runs.
The Mountain Pine Beetle tells a similar story. The Mountain Pine Beetle has been a part of British Coumbia's landscape for at least centuries and likely millenia. As their names uggests they enjoy dining on pine trees but regular cold snaps that destroyed their eggs ensured that they have never been able to consume a whole forest. Over the last ten years though they have done exactly that and oddly enough there have been no cold snaps to deal with the population. Of course, humans have helped as past forest management practices (particularly large scale fire suppression) have turned the woods into a vast buffet and our response to the infestation (cut it all down before the bugs eat it) has eliminated any chance of resistent strains of timber emerging. Nevertheless, the fact that there is vast eaten forest that is larger than Vancouver Island sitting in the middle of British Columbia suggests something fishy is going on.
Advocates of change to deal with climate change issues have to be realistic about how large scale environmental change will occur. It will not be in the style of The Day After Tomorrow with a five day storm transforming the northern hemisphere into a vast wasteland. Instead it will be a little change at a time -- a few salmon stocks in the mid-Pacific that don't return; a far outreach of the boreal forest that is converted into a grassland, a few neighborhoods of New Orelans that are not rebuilt after the last hurricane (or the next one) -- that ultimately implements the changes that will be wrought by climate change. The other danger of all of this flows from the fact that humans are so adaptable -- we can live in forests or in grasslands and given the slow pace of change many will merely choose to adapt to the changes and move on rather than try to change course.
Some will say that human adaptability is precisely why we need not worry about global warming and consequent climate change. We will adapt and progress to what ever environment is produced. In Newfoundland the fishery is now more lucrative than ever as the industry shifted from cod to crab -- but from afar it is not hard to see that rural Newfoundland is dying as the workers move to St. John's and then on to Fort McMurray. It is also not hard to see the emerging signs of trouble in the fishery. In time the oil and gas will run out off the coast and then St. John's will start to see the decline that has afflicted the whole of the province. Yes, Newfoundlanders adapted but the primary adaption over time appears to be leaving -- this is not an option on a planetwide basis.