Many of the world’s climate zones will vanish entirely by 2100, or be replaced by new, previously unseen ones, if global warming continues as expected, a study released this week said.
Rising temperatures will force existing climate zones toward higher latitudes and higher elevations, squeezing out climates at the colder extremes, and leaving room for unfamiliar climes around the equator, the study predicted.
The sweeping climatic changes will likely affect huge swaths of land from the Indonesian rainforest to the Peruvian Andes, including many known hotspots of diversity, disrupting local ecological systems and populations.
“Our findings are a logical outcome of global warming scenarios that are driven by continued emissions of carbon dioxide and other greenhouse gases,” said Jack Williams, a professor of geography at the University of Wisconsin-Madison, and author of the paper.
“The warmest areas get warmer and move outside our current range of experience and the colder areas also get warmer and so those climates disappear.”
Williams and colleagues from the University of Wyoming based their predictions on computer models that translate carbon dioxide and greenhouse gas emissions into climate change. The emissions’ estimates were taken from a report issued by the UN’s Intergovernmental Panel on Climate Change in February.
The models suggest that the climate zones covering as much as 48 percent of the earth’s landmass could disappear by 2100.
By that point, close to 40 percent of the world’s land surface area would also have a “novel” or new climate, according to the climate models.
Even if emission rates slowed due to mitigation strategies, the changes would still affect up to 20 percent of the earth’s landmass in each scenario, the authors said.
As a geographic phenomenon, the disappearing climates would likely affect tropical highlands and regions near the poles including the Colombian and Peruvian Andes, Central America, African Rift Mountains, the Zambian and Angolan Highlands.
The trend poses the greatest threat to areas of rich, but threatened, animal and plant life, in regions such as the Himalayas, the Philippines and African and South American mountain ranges. The changes could threaten some species with extinction and also displace or fragment local human populations.
As for new or novel climate zones, the phenomenon will largely affect the tropics or sub-tropics, such as the Amazonian and Indonesian rainforests, where even subtle temperature variations can have far-reaching effects, Williams said.
The study is published in the Proceedings of the National Academy of Sciences.