Global warming has become impossible to ignore, and people are slowly becoming aware of its impacts. We tend to think of heat waves or melting glaciers when we talk about this problem, but there is a consequence that many still ignore, and which is nonetheless alarming: The massive loss of plants and animals and the countless benefits they provide.
In a new report from the United Nations’ Intergovernmental Panel on Climate Change (IPCC), researchers from 67 countries have warned that global warming is putting much of the world’s biodiversity and ecosystems at risk of extinction. planet, even according to relatively conservative estimates. Never before has an IPCC report – considered the gold standard in climate science – revealed so forcefully how climate change is harming nature.
14% of all living species on earth are at risk of extinction
If the planet warms by 1.5 degrees Celsius – which is almost certain – up to 14% of all plants and animals on Earth are likely to face a high risk of extinction, according to the report. The outlook worsens if temperatures rise further; with a warming of 3 degrees, for example, up to 29% of terrestrial species could be threatened with extinction.
Over the next few decades, some plants and animals are likely to experience temperatures “exceeding their historical experience,” especially those living in polar regions, the authors wrote. Even a warming of 1.2 degrees Celsius puts many ecosystems at risk from heat waves, droughts and other extreme weather events, they added. Climate change is likely to have a greater impact on animals that are found only in one place, called endemic species.
According to experts, cheetahs, giant pandas, green turtles, Asian elephants, polar bears and jaguars will be among the first animals to evaporate from the face of the earth.
Coral reefs could shrink by 90%
Climatologists have a particularly grim prognosis for coral reefs: A warming of just 1.5 degrees Celsius could destroy up to 90% of tropical coral reefs, which are home to an incredible diversity of organisms and form the basis of many fisheries.
Global warming is hitting reefs with a double punch. The oceans absorb a third or more of the carbon dioxide that enters the atmosphere, making them more acidic over time. This is bad news for the reefs, as are the unusually warm waters. Rising ocean temperatures can cause algae that live in harmony with the coral to be expelled, in a process known as bleaching. Bleached coral is more likely to die.
“Almost all coral reefs will degrade from their current state, even if global warming remains below 2 degrees C,” the researchers write. “Their overall decline shows that we don’t need to look into the future to recognize the urgency of climate action. »
47% of species have already lost part of their population
Global warming has already extinguished local populations of many creatures – about half of the 976 species a researcher studied in 2016. The American pika, for example, has disappeared from a large swath of its former habitat in the mountains of the Sierra Nevada in California, likely due to climate change, according to a 2017 study. Adapted to cool weather, these small mammals are particularly vulnerable to unusually warm weather.
Half of the species have moved towards the poles or towards the mountains.
Climate change is also reorganizing entire ecosystems. To escape deadly temperatures, plants and animals move to (formerly) colder climates, i.e. to the poles, to the sides of mountains or to deeper waters. According to the report, almost half of all species studied have moved towards the poles or to higher altitudes. These shifts are particularly visible at sea, where species have traveled an average of 59 kilometers (37 miles) per decade towards the poles, according to the report. Large numbers of Atlantic mackerel, for example, have moved from waters near the UK and Scandinavia to Iceland, sparking geopolitical tensions over fishing rights.
Global warming is also reducing the size of many species according to several studies.
8% of the world’s agricultural land impossible to exploit by 2100
Equally troubling is the impact of climate change on food production. According to the report, a warming of just 1.6 degrees Celsius over the course of the century will render 8% of current agricultural land “climate unsuitable”. And by 2100, there will be more, not fewer, mouths to feed in the world.
The decline of fish caused by climate change also puts food security at risk, as many coastal communities around the world depend on fishing. Scientists predict that people in tropical Africa will lose up to 41% of the yield from their fisheries by the end of the century due to local extinctions of marine fish under a warming of 1.6 degrees Celsius.
Dwindling fish harvests could leave millions of people vulnerable to malnutrition, the authors wrote. Climate change also threatens the varieties of coffee, chocolate and other foods we love.
Take a moment to appreciate the plants and animals you see around you. In 50 years, a third of them may no longer exist. One in three species could be threatened with extinction by 2070. However, we can still act by remembering that these are creatures with whom we share the planet, and do what is necessary to limit the damage.
We owe them that!