This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
Biodiversity hotspots are golden places on earth where the number and diversity of animals and plants is exceptional. Environmentalists say that hotspots are the most critical of all places to protect against the ill effects of human development and climate change. The term does not mean that hotter temperatures are helpful, however. And it turns out that the biggest rises in temperature will occur where hotspots are most concentrated.
Last year a team of scientists led by Camilo Mora at the University of Hawaii published a map showing in incredible detail the year in which mean annual air temperature will rise completely out of the normal range established from 1860 to 2005. Even a cool year, then, will be hotter than a hot year from the past. That extreme will be reached by 2047 in many regions if nations continue to emit carbon dioxide at current rates. But the “new abnormal” will arise even sooner in the tropics. Unfortunately, that’s where many hotspots exist. And that’s where animals are least able to adapt to a change in temperature, because they have existed for so long in a climate that has been extremely stable.
The group created eight maps that show the global hotpots for mammals, birds, reptiles, amphibians and fishes, on land and at sea—and laid those maps on top of the map that shows future temperature change. The darker reds in the map below show the regions where temperatures will reach abnormal levels earliest, and the red outlines show the hotspots for terrestrial mammals. The overlap is alarming.
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The seven maps that follow show the same temperature zones, overlaid on the hotspots for other taxa: marine mammals, terrestrial birds, marine birds, terrestrial reptiles, marine reptiles, marine fish and amphibians. Seeing where the different hotspots are located is interesting enough. Realizing the heavy overlap with excessive temperature rise is a wake-up call.