Study: after initial extinction, biodiversity increases in warmer climates. Sept 12, 2012.
On a large scale, biodiversity decreases at a predictable rate with an increase in latitude. In other words, more species can live in hot climates than in cold climates. Strangely, analysis of fossil records dating back 540 million years previously suggested that biodiversity decreased as climates warmed. Now, a study published in the journal Proceedings of the National Academy of Sciences has used newly standardized data chronicling marine invertebrate biodiversity to refine and, in fact, contradict those earlier results. Biodiversity, in turns out, generally increases in climates marked by relatively stable warmth. Lead author Peter Mayhew and his fellow researchers are careful to note that the relationship between climatic shifts and biodiversity is not deterministic: periods of unusual biodiversity like the late Jurassic or early Cretaceous coincided with relatively cool temperatures owing to variables like sea level changes or continental dispersion. Moreover, the eventual trend towards greater biodiversity in warmer climates, which often took millions of years, was typically preceded by an initial extinction event. Tim Benton, who co-authored the article, explained that, "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." Benton's warning about global warming is well-placed in light of attempts by global warming deniers to suggest that extreme heat during, for example, the reign of the dinosaurs is evidence that life can thrive on a much-warmer planet. While true, that claim ignores that extent to which the world's current species - humans included - depend on our present temperate climate.