Oh great here I go again with the complicated long and boring ideas that form the core of my discipline. Don’t tune out just yet, this one’s easy to get your head around. I promise.
First let’s establish what a baseline is, after all this is kind of the key part of a shifting environmental baseline. A baseline is simply a fixed point in the past that we have information about. In the case of an environment, if we have information on the range of species and populations of grasslands 100 years ago we have a fixed point we can compare the present environments to. The baseline is essential if we are to evaluate the changes that have occurred within an environment over a period of time. Ideally speaking, if we are analysing the impact of human activity then we want a baseline that gives us information about an environment before we turned up on the block. This ideal baseline is where the trouble starts because we didn’t start collecting information on most environments until they had already been degraded.
A baseline is shifted when we take a date after the environments degradation as the original state of that environment. By ignoring any older information we end up accepting a degraded state as normal which has implications for conservation. After all if we restore an environment to a baseline level that occurred after degradation then have we really restored the original environment?
For instance if we take a baseline of 1930 for number of salmon in the Pacific Northwest’s Columbia River then we can see that salmon populations are today twice as large. Great! Right? Nope, salmon populations in the Columbia river were only 10% of their 1800 levels in 1930. So if we restore the population to 1930 levels before returning to exploitation then in essence we’ve not done enough to ensure the long term survival of salmon populations in the Columbia Rivers.
I’m probably not doing this justice but thankfully this quote from the terms creator Daniel Pauly (who coined the term in 1995) might do it better.
“We transform the world, but we don’t remember it. We adjust our baseline to the new level, and we don’t recall what was there. If you generalize this, something like this happens. You have on the y axis some good thing: biodiversity, numbers of orca, the greenness of your country, the water supply. And over time it changes — it changes because people do things, or naturally. Every generation will use the images that they got at the beginning of their conscious lives as a standard and will extrapolate forward. And the difference then, they perceive as a loss. But they don’t perceive what happened before as a loss. You can have a succession of changes. At the end you want to sustain miserable leftovers. And that, to a large extent, is what we want to do now. We want to sustain things that are gone or things that are not the way they were.” Daniel Pauly in a 2010 TED talk