Global warming already affecting species
Parmesan's early studies of checkerspot butterflies were among the first to record shifts in a species’ habitat due to climate change. (Photo: Anne Toel)
Camille Parmesan: The surprising thing is that we haven’t really had that much warming yet. We’ve only had about 1 degree Fahrenheit. But we’re already seeing impacts in every single system that’s been studied around the world. So every continent, every ocean, every group of animal and plant.
That’s biologist Camille Parmesan of the University of Texas. Her early studies of butterflies were among the first to record shifts in a species’ habitat due to climate change. Now, she said, many species are on the move.
Camille Parmesan: About 40% of species are changing where they live by moving themselves up towards the poles, and up mountains. And about 60% change the timing of when they do things in spring. So when leaves emerge, when caterpillars emerge, when birds start to migrate.
The Intergovernmental Panel on Climate Change has predicted the planet will warm up anywhere from 4 to 11 degrees Fahrenheit in this century.
Camille Parmesan: Really, we don’t want to get above another 2 degrees warming. And if it gets up to 6 degrees warming, we’ve basically changed Earth’s atmosphere so much that we’re going back to a time when the biodiversity was a completely different group of plants and animals. So if we really do go up to 6 degrees warming, what we’re expecting to see is a complete new shift in what kind of life exists on Earth.
Parmesan said permanent changes in climate are making it more difficult to preserve endangered species.
Camille Parmesan: These are already living at the limits of what their habitat is. And so the mountaintop and polar species don’t have anywhere to go, they’re very likely to die off. Even ones that live at lower elevation, if you’re living in a tiny nature field – and you’re surrounded by cornfields – it’s very difficult for you to move to track the climate as it’s changing.
She told EarthSky that conservationists need a new “toolbox.”
Camille Parmesan: As a conservation biologists, we know we can’t save all biodiversity. But there is a certain set of species that are again, very restricted, have barriers to movement that we consider at high risk from climate change. And I think it’s these that we need to start considering some fairly radical approaches to how to preserve them over the next hundred years.
Most species today exist because they were able to adapt to the rapid and extreme global warming that occurred at the onset of our current interglacial period. Species migrated to environments that offered a niche for survival. When conditions changed, they migrated again. Today, migration is no longer an option for many species as cities, fences, and gaps in habitat impose insurmountable obstacles. Only those species that exist on the fringe of human habitation have an option to move away from human population which inevitably pushes them up the mountain and towards less hospitable environments. Thus, species are being pushed to the limits of range where even the slightest change in environment will indeed wipe them out.
The one degree temperature change that has occurred over the past several centuries would not have a significant impact on most species unless there were other underlying and more profound stresses that have pushed them to vulnerability. I doubt that a one degree change in temperature will have any more impact than to marginally change the timing of the inevitable demise of many species.
I am concerned that we have become so invested in the belief that global warming is the cause for most ecological disasters in the making that we have developed tunnel vision and are loosing our ability to see immediate and impactful solutions to our effects on animal habitat. We have overcomplicated the solutions and deferred environmental responsibility to UN committees to the harm of many good environmental programs.
I cut my CO2 footprint in half but it will take 100 years to know if it had any effect. I also work in programs to clean up pollution and restore habitat. I will know in 10 years that it saved a species poised for extinction. Cutting CO2 is good but doing it with tunnel vision and failing to see that CO2 has very little to do with the root cause of why many species are at the brink of extinction does little to change their fate.