Not too late to reverse dramatic declines in biodiversity

Climate change species loss
CC BY 2.0 Tony Fischer Photography

Take a look around you. If you have been worrying about pandas, elephants, or other endangered species, it is time to start looking closer to home...because things could look quite different within your lifetime.

Just days after the Mauna Loa observatory recorded the first exceedance of 400 ppm carbon dioxide in earth's atmosphere, a report in the journal Nature Climate Change describes what we can expect if climate change continues unmitigated.

Living spaces cut in half

Dr. Rachel Warren, of the Tyndall Centre for Climate Change Research at the University of East Anglia, led a study that assessed 50,000 common species around the globe. The study's models showed more than half (57%±6%) of flora and one third (34%±7%) of fauna "are likely to lose ≥50% of their present climatic range by the 2080s."

What does this mean? Basically, the study assumes that as things warm up, plants and animals will move to a more suitable climate. It estimates an envelop of parameters for just how quickly each species can relocate itself. So the halving of a species range is not based on simply eliminating parts of their current range that heat up too much.

The models bring to light a a number of factors in such a global climate-driven migration. For example, more mobile species, like birds, will travel to new climes more quickly. But a group will disperse in many directions to find a more suitable home, leading to a high rate of deaths in the groups that select their new territory incorrectly.

The model does not account for direct impacts to species due to higher CO2 levels, for example earlier stomatal closing, which could affect how a species thrives or fails. Similarly, the models neglect complex coupled phenomena like the rise of diseases, invasive species, or the failure of one species as the species upon which is codepends disappears. Animals may decline faster than predicted in these models as the species on which they feed are threatened.

The effect of biodiversity loss due to climate change on humans remains a big question mark. We are also codependent on many of these species for cleaning our air and water, for nurturing the foods we consume, and other beneficial

The time to act is now

The study does offer hope in the case that we are spurred to rapid action to mitigate climate change. Dr Warren reports:
Prompt and stringent action to reduce greenhouse gas emissions globally would reduce these biodiversity losses by 60 per cent if global emissions peak in 2016, or by 40 per cent if emissions peak in 2030, showing that early action is very beneficial. This will both reduce the amount of climate change and also slow climate change down, making it easier for species and humans to adapt.

The rate of temperature change poses the challenge: when species cannot adapt quickly enough, a domino chain of biodiversity loss with the potential to bring down human civilizations begins. If we can slow down the rate of change, we have a better chance of helping our species win the race to stay one step ahead of our changing planet.

The study also points out the value of citizen scientists, crediting the data in the Global Biodiversity Information Facility (GBIF) as crucial to a study of this scope and magnitude.

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