Again, the use of a geographical approach (and here defining biodiversity as ‘biotic intactness’) shows the Holocene-Anthropocene Mass Extinction is progressing faster then generally thought – and ‘biodiversity safe limits’, however arbitrarily defined, have already been passed on most of the planet’s land surface.
Whether you focus on mammals, birds, reptiles or amphibians – land vertebrates are in rapid decline everywhere around us, illustrating a general decline of Life on Earth – and a prelude to the Holocene-Anthropocene Mass Extinction, that is being underestimated in speed and severity.
The reason of this underestimation: demography – the decline of species populations. This is not always counted in when assessing the global ecological crisis, but if you do, you get to see that the actual trend is much worse than most people think…
If you live inside a heap of compost in someone’s backyard, your life may already feel quite miserable. But if you’re really tiny, at least you’re probably thinking your chances of surviving climate chance are –comparatively– okay.
Well, our dear little springtail –we hate to bring it to you– but science may have bad news. Sometimes it’s just not fair.
If what goes for worms goes for the wider world, there is an important lesson to be learned: in order to prevent extinctions, we need to improve ecosystem health – before climate change kicks in.
That is because ecosystems with larger natural diversity have better adaptive mechanisms – allowing the preservation of more biodiversity.
Predictive models that can forecast biodiversity decline under anthropogenic climate change used to be too simplistic, as these ignored crucial biological mechanisms such as demography, dispersal, evolution, and species interactions (for instance species competition and ecosystem dependence).
Fortunately these climate-biodiversity models are improving. But in order to also improve the quality of their biodiversity predictions these improved models now require more – and better data.
Climate change leads to species extinctions and exponentially so: the loss of biodiversity is set to accelerate under continuation of global average temperature rise.
Yes, we found yet another publication that is critical of one-dimensional biodiversity loss projections of climate change – and again it is a component of interspecies interaction that may be underestimated. We’ve previously looked at species competition and at evolutionary responses, and today we add species’ interdependence – the ecosystem perspective:
As species migrate in response to climate change and do so at different rates and dispersal directions, extra ecosystem disturbances might arise, leading to temporary local biodiversity increases – fuelling a net (global) downward trend.