I was on the edge of an on-line conversation recently. A small group of coral reef scientists were discussing what we should call coral reefs after they have been degraded. Sounds trivial, but this was a serious conversation – science needs a name for this new kind of ecosystem. I did not hang around, so don’t know if they came up with a good name. I don’t think it will matter much what they call it, because as people we will all continue calling them coral reefs until the last tiny nubbin of coral dies.
Are these both coral reefs? Photos from the Line Islands © Scripps Institution of Oceanography.
That’s what the term, shifting baselines, means – we are very good at failing to notice environmental changes that are not abrupt. Sometime back in 1997, I was at a workshop in Florida at which we were developing the monitoring methods that would be used in the reef survey system known as AGRRA – the Atlantic and Gulf Rapid Reef Assessment program. Twenty years later, AGRRA is going strong, a Caribbean-wide monitoring program that engages sport divers as volunteers who report on reef health.
In the course of our discussions at the workshop, coral ecologist, Judy Lang, was outlining the procedure for randomly selecting coral colonies that would then be measured to provide information on population structure. The procedure, as I remember it, was to stretch out a 30-meter tape, and at previously decided random points along the tape locate the closest coral colony at least 10 cm in diameter. The set of closest colonies would be the ones measured, a random sample from the population of colonies available.
A question arose. One of the reef managers participating in the workshop, asked what should be done if there were no coral colonies larger than 10 cm in diameter. Judy looked confused and said that its okay to move a meter or so away from the tape to sample the closest colony of that size. The questioner, a reef manager from Veracruz, Mexico, explained that she did not think she’d be able to find corals 10 cm in diameter anywhere on the reefs she was managing. I’d been vaguely listening, after all, I was a fish guy and these messy details about corals were not what got me excited. But I pricked up my ears at that exchange, realizing, as did Judy and lots of other people at the workshop, that what we called a coral reef could be a very different thing from place to place, even back then. The reefs in the vicinity of Veracruz, like reefs in many places round the world that are close to harbors or other human activity, had been severely degraded well before the late 1990s, but we still called them coral reefs.
Fast forward to 2021, well into the Anthropocene, and we can see examples of shifting baselines everywhere we look. WWF’s Living Planet Index (LPI) reports the average rate of loss of abundance of animal populations since 1970. In their 2020 Living Planet Report, the global LPI for nearly 21,000 populations of some 4,392 species of mammal, bird, reptile, amphibian and fish showed a 68% average loss in abundance. That is, there are 2/3 fewer individuals of those species on the planet than there were just 50 years ago. Most of us seem unaware of this loss, which is not restricted to vertebrates or to land animals.
The global Living Planet Index has fallen 68% since 1970. Image © WWF.
There are plenty of similar statistics. Over the last 50 years, the global economy has increased nearly fivefold, the human population has doubled, and our continued expansion over and alteration of land surfaces means that we now have modified 75% of all land on the planet, mostly for agriculture. We are also extracting twice the natural resources as we once were. Our deforestation and land clearing has removed about half the total plant biomass on the planet, and we have caused major shifts in animal biomass as well. Over the course of human civilization, we have reduced the total biomass of wild land mammals about six-fold, although the growth in our own numbers and in our domesticated animals have increased the total biomass of all land mammals (including us) about four-fold. (That’s wild ones six times fewer than before we got started, but wild plus domesticated four times as many!) In the oceans, our fishing has reduced the biomass of organisms present by about 90% in only the last 50 years. Globally! Such massive changes in biomass on land and in the ocean, on a global scale, will be accompanied by similar pronounced changes in trophic structure and patterns of energy flow. Mostly we are quite unaware of this, assuming the natural world is more or less as it was when we or our parents were young.
This chart, based on data from Vaclav Smil and Paul Chefurka shows the trend in terrestrial vertebrate biomass over the course of human civilization. Image © Greenpeace International.
Most of us live in cities, and our need for food and shelter is only distantly linked to the natural world. Food arrives in supermarkets, or is delivered to our doorways, and housing is rented or purchased rather than constructed by each of us using natural products. Rainfall is an inconvenience for our self-important lives rather than a necessity for our crops. Our employment seldom involves interaction with nature, although it sometimes includes cutting down, digging up or blasting nature to bits. Mostly, of course, it is done within buildings, using various skills to contribute to our decidedly artificial economy. There weren’t any office managers, event coordinators, concierges or life coaches very long ago. Much of our recreation is also entirely virtual, totally divorced from although sometimes mimicking the natural world around us, and even our outdoor recreation tends to be wrapped around economically valuable inventions like golf courses, wake boats, planes, and on- and off-road vehicles of many types. Each generation seems to become more removed from the natural world than the one that preceded it, so the fact that we mostly are unaware of the changes we have wrought on the planet is hardly surprising.
Hardly surprising, but with a huge cost. With people largely unaware of the tremendous changes we have been causing in the natural world, the idea that we are causing problems that could come back to bite us seems overwrought to most who hear of it. The lack of urgency with which the world has greeted the need to act on climate change, or on any of the other environmental problems we have been causing, is understandable. Just because a few environmentalists – or even many environmentalists – talk about the environmental crisis using words like ‘existential’ is not going to make the world sit up and take notice if the vast majority of us are quite unaware of the extent to which we have been, and still are, modifying this planet. Our individual lives seem to be going just fine.
What can be done to create more awareness of nature, and of our impacts on nature? First, we have got to convey the messages as graphically as possible, using simple words to convey the magnitude of what we are doing. We also need effective messages that explain concepts like exponential growth, since many of our impacts are growing rapidly and few people understand percentages, risk estimates, or exponential growth intuitively. Few of us even appreciate the immense difference between one thousand and one billion. Second, we should not suppose that ‘people have heard all this before’ – they have, but they have not really heard it, so we must be willing to repeat and repeat and repeat. While repeating, convey the messages in slightly different ways to retain some newness, and focus more on showing than telling. We have a powerful and capable advertising/promotion industry that should be fully engaged in this task. Third, we need to support every effort to re-immerse people in the natural world, plus start some new efforts: outdoor, unstructured play for younger children, required outdoor education for older kids and teens, emphasis on all those athletic endeavors that get people competing with themselves and mastering skills for interacting with nature. Finally, we should be brave enough to confront the absurd impossibility of a perpetually growing economy, and to question our tendency to conflate quality of life with monetary cost. If we don’t make concerted efforts to take these steps, we will, indeed, come to accept the changing world of the Anthropocene, assuming it is inevitable, not something we can change. And until our own lives are directly threatened by environmental crises we will hardly notice how massively our planet is being changed.
Image © BCCDC Foundation (a health NGO which recognizes the links we have to environment)