Global warming, climate change, and species extinctions

In the latest study of the effect that global warming and climate change may have on species extinctions, a study from the University of Connecticut concludes that up to one in six species may be at risk of extinction, depending in the amount of global warming that actually occurs. The study is what is called a meta-analysis; it combined and summarized the data from all of the available global warming -species extinction studies available that met certain criteria of relevance and quality - 131 studies in all.

The results of the study suggest that only 5% of species would become extinct if global warming could be kept to the international agreed-upon target of just 2 degrees centigrade above pre-industrial levels. But virtually no one believes now that we can keep global warming to that limit, given our failure to curb global warming so far. Many of the individual studies summarized in the present meta-analysis predict global warming of more than 4 degrees centigrade, leading to the higher estimate of 1 in 6 species at risk of extinction (about 16%). Most of the extinctions will occur in the tropics, according to the analysis.

Current climate change models predict only what might happen in the time period of decades or centuries. Extinctions might be much higher if higher global temperatures were to persist for tens of thousands of years. Indeed, some scientists think we may be entering a prolonged period that will become the sixth mass extinction experienced by Earth over its 4 billion life span so far.

Many species are likely to be affected by global warming and climate change, even if they do not become extinct. Species may undergo substantial changes in populations, range, and interactions with other species, for example. The good news is that over prolonged periods of time (thousands to millions of years), evolution will continue and species will adapt and change. Life will go on, though whether humans will still be here is anybody's guess.