Five major El Niño events per century could lead to fewer fishes that thrive in cold water and more terrestrial birds in eastern coastal ecosystems.
(Margaret Osborne)
As climate change continues to intensify, some scientists predict La Niña and El Niño events, opposing climate patterns that recur in the Pacific Ocean, will become stronger and more frequent, leading to shifting hurricane patterns, flooding, and droughts. Already this century, the Earth is on track for a “triple dip” of three consecutive La Niña events, which researchers say may worsen drought in the Horn of Africa and southern South America, and lead to increased rainfall in Southeast Asia and Australasia. How exactly these more intense events will affect life on Earth in the future is unknown, but researchers at the University of Utah are looking to the past for answers.
In a study published September 8 in Science, the team used animal fossils and human artifacts from the past 12,000 years to identify an “ecological tipping point” of five moderate-to-strong El Niño events in eastern coastal ecosystems—that is, after five such El Niño events within a century, populations of marine and terrestrial birds and marine fishes began to shift.
group of people standing on rock outcropping with ocean in distance
HomeNews & Opinion
Repeated El Niño Events Could Spark Big Ecological Shifts
Five major El Niño events per century could lead to fewer fishes that thrive in cold water and more terrestrial birds in eastern coastal ecosystems.
Margaret Osborne
Margaret Osborne
Sep 19, 2022
PDF VERSION
19
ABOVE:
The research team at the excavation site
ISAAC HART
As climate change continues to intensify, some scientists predict La Niña and El Niño events, opposing climate patterns that recur in the Pacific Ocean, will become stronger and more frequent, leading to shifting hurricane patterns, flooding, and droughts. Already this century, the Earth is on track for a “triple dip” of three consecutive La Niña events, which researchers say may worsen drought in the Horn of Africa and southern South America, and lead to increased rainfall in Southeast Asia and Australasia. How exactly these more intense events will affect life on Earth in the future is unknown, but researchers at the University of Utah are looking to the past for answers.
In a study published September 8 in Science, the team used animal fossils and human artifacts from the past 12,000 years to identify an “ecological tipping point” of five moderate-to-strong El Niño events in eastern coastal ecosystems—that is, after five such El Niño events within a century, populations of marine and terrestrial birds and marine fishes began to shift.
The El Niño-Southern Oscillation (ENSO) is a recurring climate pattern made up of three cycles: El Niño, La Niña and ENSO neutral. During an El Niño event, east-to-west trade winds weaken or reverse, waters in the central and eastern tropical Pacific Ocean heat up, and this area sees increased rainfall. Globally, El Niño usually results in higher than average temperatures and a less active hurricane season in the Atlantic. Off the coast of Baja California, El Niño decreases nutrient upwelling, reduces marine biomass and increases precipitation, write anthropologist Daniel Sandweiss and climate scientist Kirk Maasch in a perspective article about the study.
In contrast, La Niña usually causes lower than average temperatures across the world and cooler ocean temperatures in the central and eastern tropical Pacific. During La Niña, the easterly winds along the equator blow faster and hurricanes become stronger and more frequent in the Atlantic.
group of people standing on rock outcropping with ocean in distance
HomeNews & Opinion
Repeated El Niño Events Could Spark Big Ecological Shifts
Five major El Niño events per century could lead to fewer fishes that thrive in cold water and more terrestrial birds in eastern coastal ecosystems.
Margaret Osborne
Margaret Osborne
Sep 19, 2022
PDF VERSION
19
ABOVE:
The research team at the excavation site
ISAAC HART
As climate change continues to intensify, some scientists predict La Niña and El Niño events, opposing climate patterns that recur in the Pacific Ocean, will become stronger and more frequent, leading to shifting hurricane patterns, flooding, and droughts. Already this century, the Earth is on track for a “triple dip” of three consecutive La Niña events, which researchers say may worsen drought in the Horn of Africa and southern South America, and lead to increased rainfall in Southeast Asia and Australasia. How exactly these more intense events will affect life on Earth in the future is unknown, but researchers at the University of Utah are looking to the past for answers.
In a study published September 8 in Science, the team used animal fossils and human artifacts from the past 12,000 years to identify an “ecological tipping point” of five moderate-to-strong El Niño events in eastern coastal ecosystems—that is, after five such El Niño events within a century, populations of marine and terrestrial birds and marine fishes began to shift.
The El Niño-Southern Oscillation (ENSO) is a recurring climate pattern made up of three cycles: El Niño, La Niña and ENSO neutral. During an El Niño event, east-to-west trade winds weaken or reverse, waters in the central and eastern tropical Pacific Ocean heat up, and this area sees increased rainfall. Globally, El Niño usually results in higher than average temperatures and a less active hurricane season in the Atlantic. Off the coast of Baja California, El Niño decreases nutrient upwelling, reduces marine biomass and increases precipitation, write anthropologist Daniel Sandweiss and climate scientist Kirk Maasch in a perspective article about the study.
In contrast, La Niña usually causes lower than average temperatures across the world and cooler ocean temperatures in the central and eastern tropical Pacific. During La Niña, the easterly winds along the equator blow faster and hurricanes become stronger and more frequent in the Atlantic.
Because of the effects of El Niño on ocean temperatures and rainfall, study coauthor Jack Broughton, an anthropologist at the University of Utah, hypothesized that some animals—terrestrial birds such as quails and meadowlarks—would thrive more under El Niño conditions, while marine birds would suffer. Similarly, populations of fishes that do well in colder water, like kelp bass and rockfish, would likely decline during El Niño events, while fishes that prefer warmer water or can live under varying conditions would increase.
To test this idea, the team identified 18,623 specimens that had been excavated from a site called Abrigo de los Escorpiones in Baja California, Mexico, matching each tiny bone fragment to a reference collection of all known species in the area. The work was laborious—researchers began the process 14 years ago, in 2008.
Wolves, brown bears and white-tailed eagles are among the top predators making a comeback across Europe, according to a major report that looks at how some wildlife is rebounding.
Researchers analysed data on 50 wildlife species whose population size and geographical distribution have expanded over the past 40 years to show how effective legal protection, habitat restoration and reintroductions can drive species recovery.
“The vast majority have recovered thanks to human efforts,” said Louise McRae from the Zoological Society of London (ZSL), who was one of the authors of the European Wildlife Comeback report, commissioned by Rewilding Europe. “As a researcher working on global biodiversity and looking at global trends, it can be quite depressing hearing the latest statistics, but this report is really exciting, encouraging and inspires people like me to keep doing what we’re doing.”
The grey wolf has been the fastest to return among carnivores. For centuries they were killed by humans, until a low-point during the 1970s when there were only a few populations hanging on in pockets of south and north-eastern Europe. Since the introduction of legislation to protect them, and more public tolerance of living alongside them, numbers have increased by 1,800%. There are 17,000 individuals roaming almost all of continental Europe, with calls to reintroduce them to Britain too.
There are 12,500 pairs of white-tailed eagles soaring over much of Europe, with growing populations on the west coast of Scotland and the Isle of Wight. Across Europe, there has been a 445% increase in numbers between 1970 and 2018, mainly thanks to legal protection and the banning of damaging pesticides.
Since 1960, populations of brown bears have increased by 44%, driven by better legal protection, although persecution is still a big risk and human-bear conflicts continue. “Coexistence with species like carnivores is still a challenge, but attitudes are changing – we’re still learning about ways to live alongside these species,” said McRae.
[Other 'come backs' access the link on top]
