"Catastrophic" mass extinction is likely within the next 100 years as the earth's temperature increases approximately 6º C and carbon dioxide accumulates in the atmosphere, predict scientists studying the last time the temperature rose rapidly by that much—55 million years ago.
Animals will shrink in order to survive and adapt to exist on less nourishing food, according to the Bighorn Basin Coring Project, currently being conducted by scientists from the US, UK, Germany and the Netherlands who are studying the last time the planet's temperature rose rapidly by 6º C, Climate News Network reports.
Dr. Phillip Jardine of Birmingham University in the UK, among the leaders of the study, said the previous period of warming "led to catastrophic extinctions of life in the deep oceans, partly because of increased acidification and partly through lack of oxygen."
"What worries the scientists is that this current warming period will take as little as 200 years, if the Intergovernmental Panel on Climate Change is correct," Joint Editor Paul Brown reports for Climate News Network. "This gives many long-lived species, for example trees, no time to evolve and migrate. ... The result will be mass extinction, and for the survivors, humans, animals and insects, there will be a scramble to eat a diminishing and less nutritious food supply."
Asked by Climate News Network what affect a 6º C increase would have on the planet currently if not enough action is taken to curb emissions, Jardine said:
For me this just shows how pervasive the impacts of altering the global carbon balance really are. Even if future climate change isn’t a convincing enough argument to decrease carbon emissions, increasing atmospheric CO2 concentrations has a very real possibility of reducing the viability of our own food supplies, by compromising the base of the food chain for ourselves and the animals that we farm and eat. If we acknowledge the presence of increasing temperatures then we have an additional factor that we would expect to decrease further the size of our farmed animals, and thus the amount of food that we can take from them. I would say that the impacts of this on a large and growing human population could be catastrophic, especially in the developing world and when changes in other resources, for example water, are factored in as well.
Following is the National Geographic video, "6 Degrees Warmer: Mass Extinction?"