THE END

I had thought when I set out that this blog would focus on the specific effects that climate change would have upon freshwater ecosystems, which I now realize stemmed from two prior assumptions: that climate change would have a huge negative effect on biodiversity and that science had a pretty good idea of what that would be. Although I don't think these are entirely incorrect, I have encountered far more ambiguity than expected (and hoped to be honest - after all it would be nice if science could provide answers to environmental problems!). While predictive studies expect huge biodiversity losses in the future, examples of a warmer planet from paleoecology don't always agree with this widely accepted idea. While many specialized or isolated freshwater species are likely to become extinct, others will be able to expand their ranges or will flourish in their native environment as temperatures rise toward their physiological optima. There are certain areas where understanding is seriously lacking; how will climate change affect ecosystem functioning, particularly food web dynamics? How many species will go extinct, and what will be the most important factor behind this? 

I currently think that in combination with a range of other anthropogenic threats, climate change will affect every ecosystem on Earth to some degree. I expect there to be both positive and negative changes in biodiversity on a local scale, as the impact of climate change plays out, but I think it's probable that global biodiversity will decrease unless habitat fragmentation is improved. These opinions are pretty tentative - there are still huge knowledge gaps in this branch of science. Perhaps, despite my ranting at Le Page's New Scientist article, the question "How serious a threat is global warming to life?" is an 'unknown' after all...