Climate change is no longer a future threat for many species. A recent international study, published in Nature Climate Change, found alarming evidence of responses to recent climate changes in almost 700 birds and mammal species.
The study made a systematic review of 130 scientific reports that were published in the last 25 years, dealing with the observed impacts of climate change on birds and mammals, making it the most comprehensive assessment on the topic to date.
Under-reported and under-estimated
“There has been a massive under-reporting of these impacts”, said co-author James Watson, “Only seven per cent of mammals and four per cent of birds that showed a negative response to climate change are currently considered ‘threatened by climate change and severe weather’ by the IUCN – the International Union for the Conservation of Nature.”
The new results, however, have shown evidence of response to recent climate change during the last 100 years in 700 species, and suggest that around half the threatened mammals and just under a quarter of the threatened birds that were taken up in the study have already responded negatively to climate change.
“This also implies that these species have a high probability of being negatively affected by future climatic changes” said lead author Michela Pacifici of the Global Mammal Assessment Program at Sapienza University in Rome.
Mountain gorillas (Gorilla beringei beringei) possess a number of traits that contribute to their resilience to a changing climate: they are tolerant of a wide range of temperatures, are exposed to fairly high climate variability, have low freshwater requirements, and feed on a variety of abundant food.
However, a number of other traits make them vulnerable to a changing climate. Their population is very small and their range highly restricted. A limited dispersal ability (due to human settlements), coupled with a long generation time, a low reproductive rate, and low amounts of genetic variation, will limit the ability of the species to adapt to a changing climate.
-World Wildlife Fund
The study thus clearly shows that the impact of climate change on mammals and birds has been greatly under-estimated and under-reported. These two animal categories, however, contain many well-studied threatened and endangered species, and the researchers fear less studied groups like fish, reptiles, amphibians and plants are all in the same boat.
“This under-reporting is also very likely in less studied species groups. We need to greatly improve assessments of the impacts of climate change on all species right now,” said co-author James Watson.
In an interview with the Guardian, Watson explained how the assessments of red-list species have thus far assumed that hunting, deforestation, and loss of habitat form a larger threat to endangered species. With this study, climate change is added to the list of key-factors driving animal extinction.
The way scientific studies on climate change and species are being conducted also seems outdated, with projections and models being made 50 to 100 year in the future, while the change is already taking place now.
Conservation agency WWF has been forewarning the current impact of climate change on species for years: their scientists have estimated that most species, including plants, will have to migrate away from increasingly less favourable climatic conditions at a pace of 1.000 meters per year if they are to keep within the climate zone they need to survive in. Many species will not be able to redistribute or adapt fast enough to keep up with the ever-increasing changes.
These results need to be considered in efforts to safeguard the future of biodiversity, says Watson: “We need to communicate the impacts of climate change to the wider public and we need to ensure key decision-makers know significant change needs to happen now to stop species going extinct.”