This week President Obama announced a Climate Action Plan to address the enormous and growing costs of climate change. He talked about the impacts of climate change on society – devastating natural disasters like Hurricane Sandy, raging wildfires, diminished snowpacks, depleted water supplies and drought wilting farmers’ crops. As a conservation biologist, I get the urgency of climate action for society, but also for the many life forms with which we share the planet.
It is clear that the stakes of climate change are rising for biodiversity. A recent study* in the journal Nature Climate Change predicted a shocking decline of global biodiversity within this century if nations fail to take quick, effective actions to halt greenhouse gas emissions. Roughly one third of common and widespread animal species and over half of plant species will disappear from a large percentage of their current ranges if society does not take action on climate change, the research team predicted.
Plants, reptiles and amphibians are likely to suffer the most because climate change will outpace these organisms' abilities to shift to new locations as conditions change. Sub-Saharan Africa, Central America, Amazonia, Australia, North Africa, Central Asia and Southeastern Europe will become especially inhospitable for plants and animals if emissions continue to rise unchecked.
Without action to mitigate global warming, the ranges of many common, widespread plant and animal species will shrink by at least half, according to the team who modeled the effects of six climate change mitigation scenarios on a huge number of species (48,786 to be exact).
The study may actually have understated the problem because it didn’t take into account other impacts that will interact with climate change, like diseases and pests, land-use changes, pollution, physical barriers to species movement, and increasingly frequent extreme weather events. The authors also pointed out that the actual rate of greenhouse gas emissions is outpacing the projected emissions levels in the models they used.
There is hope, though, to be gleaned in their finding that with "prompt, stringent mitigation of greenhouse gas emissions," species could avoid roughly 60 percent of the losses to their current ranges. However, that would require that nations rapidly rein in global emissions so that they peak before 2030. We have an Administration that has shown itself ready to lead on this issue. However, if society delays action, the chances of curbing species losses are significantly reduced.
I share President Obama’s impatience with climate change skeptics attempting to slow down our response to this urgent matter. As he said in his speech at Georgetown University, “There is no time for a meeting of the Flat Earth Society.” As it turns out, even the president of the Flat Earth Society, which promotes the idea that the earth is flat, not round, believes that human-induced climate change is real.
*Warren, R. et al. 2013. Quantifying the benefit of early climate change mitigation in avoiding biodiversity loss. Nature Climate Change 3, pp. 678–682. doi: 10.1038/nclimate1887.