Biodiversity Typically Rises with Higher Temperatures, but Not this Time
Looking back through the eons of the Earth's history by studying fossil and geological records, a trend appears. Biodiversity, or the abundance of life, generally increases as the planet warms. More heat creates more energy for plants and animals to thrive. Of course, not all species flourish in a warmer environment. Many will go extinct as others grow more numerous, but the overall number normally increases. Unfortunately, we will not likely see any rebound in biodiversity during our currently changing climate. According to a new study from the University of Leeds, it is the speed at which the climate is changing that will instead cause biodiversity loss. Some species die off, but others cannot fill the void because there is not enough time to evolve.
The Leeds researchers set out to refine a previous study of biodiversity over the same time interval. That study concluded that a warming climate would lead to lower biodiversity. To prove this wrong, the researchers examined patters of marine invertebrates over the last 540 million years.
According to lead author, Dr. Peter Mayhew of the Department of Biology at York, "The improved data give us a more secure picture of the impact of warmer temperatures on marine biodiversity and they show that, as before, there is more extinction and origination in warm geological periods. But, overall, warm climates seem to boost biodiversity in the very long run, rather than reducing it."
"Science progresses by constantly re-examining conclusions in the light of better data," said Professor Tim Benton of the Faculty of Biological Sciences at the University of Leeds. "Our results seem to show that temperature improves biodiversity through time as well as across space. However, they do not suggest that current global warming is good for existing species. Increases in global diversity take millions of years, and in the meantime we expect extinctions to occur."
Dr. Alistair McGowan of the School of Geographical and Earth Sciences at the University of Glasgow added, "The previous findings always seemed paradoxical. Ecological studies show that species richness consistently increases towards the Equator, where it is warm, yet the relationship between biodiversity and temperature through time appeared to be the opposite. Our new results reverse these conclusions and bring them into line with the ecological pattern."
The study has been published in the Proceedings of the National Academy of Sciences (PNAS)
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