Emperor penguins could be wiped out in 80 years if the current rate of global warming continues
Emperor penguins that inhabit the south pole might just get wiped out from the face of the earth by the end of the century if global warming continues unchecked.
However, if countries reduce their emissions and meet the Paris climate accord, there will be an estimated 19% drop in the number of penguin colonies, according to researchers.
The fate of the population rests on the integrity of the sea ice, a site where the penguins breed. A warming climate means more sea ice melting. Emperor penguins are choosy about their breeding sites: they tend to build their colonies on ice that is locked into the shoreline of the Antarctic continent but also close enough to open seawater to give the birds access to food for themselves and their young. With the warming climate, the sea ice will gradually disappear, and the penguins could lose their habitat, food sources, and ability to hatch chicks.
Previously, the world’s second largest emperor penguin colony, Halley Bay, collapsed causing thousands of chicks to drown overnight. Since the event in 2016, scientists have not detected any breeding in the area.
Low sea ice has triggered a decline in the population before. She explains that low-sea ice cover in the 1970s caused a dramatic population decline -- from approximately 6,000 breeding pairs to 3,000 -- when several consecutive years of low sea-ice cover caused widespread deaths among male penguins.
It is challenging to monitor changes in the population. Dr Stephanie Jenouvrier, a seabird ecologist at WHOI and lead author on the paper, explains. "We do not have much observation because emperor penguins breed during the most remote place on earth and harshest climate. For more than 60 years, one colony in Terre Adélie (Antarctica) has been the focus of extensive observation and research that has enabled us to understand the effect of sea ice conditions on both the mortality and fecundity of the birds, hence the population dynamics," Jenouvrier told MEA WorldWide (MEAWW).
Because it is challenging to monitor the changes in the population, Jenouvrier and the team developed mathematical models to see how these birds will cope with future environmental changes.
"We've been developing that penguin model for 10 years. It can give a very detailed account of how sea ice affects the life cycle of emperor penguins, their reproduction, and their mortality," says Jenouvrier.
The team ran the model by factoring in three different estimates of future temperatures. If the global temperature in the future increases by only 1.5 degrees Celsius -- the goal set out by the Paris climate accord -- they predict that Antarctica will lose only 5% of sea ice by 2100, causing a 19% drop in the number of penguin colonies.
If countries do not meet the Paris target and global temperatures increase by 2 degrees Celsius, the find that the loss of sea ice nearly triples, and more than a third of existing colonies will disappear.
And in a scenario where no action is taken to reduce climate change, they expect a 5 to 6 degrees Celsius rise in temperature. At that temperature, we could stand to lose all of the colonies."Under that scenario, the penguins will effectively be marching towards extinction over the next century," explains Jenouvrier.
There is still a lot of uncertainty as to how emperors will react as the world warms, but their future looks bleak if emissions aren’t cut rapidly, Peter Fretwell at the British Antarctic Survey, who wasn’t involved in the study, told NewScientist. He adds, “The difference between a scenario where we do halt global warming and one where we don’t is stark.”
The study has been published in the journal Global Change Biology.