Editor's note: News about conservation and the environment is made every day, but some of it can fly under the radar. In a recurring feature, Conservation News shares three stories from the past week that you should know about.
In a warming world, cactuses may not be able to beat the heat.
The story: Cactuses may seem impervious to the threat of climate change — after all, many of them thrive in extreme heat. However, a new study — co-authored by Conservation International scientist Patrick Roehrdanz — shows that global warming could put 60 percent of cactus species at greater risk of extinction by 2050, reports Raymond Zhong for The New York Times.
Botanist David G. Williams told The New York Times that perceived resilience is not always reality when it comes to cacti: “It’s a popular image of cacti. Ah, we don’t have to worry about cacti. Look at them, they’ve got spines, they grow in this terrible environment.”
But the truth is, cactus species grow all over the world — from the rainforests of Brazil to limestone cliffs in Mexico — and are vulnerable to even the smallest shifts in temperature and humidity. According to the study, cactuses are most at risk where their diversity is the highest, in places such as Florida, central Mexico and large swaths of Brazil.
The big picture: “There are a lot of these tipping points and thresholds and interactions that are very fragile and responsive to changes in the environment, land use and climate change,” Williams said.
Climate change isn’t the only thing pushing cactuses to their tipping point: Poaching and habitat destruction make these prickly plants one of the world’s most endangered groups of organisms.
The loss of cactuses could be catastrophic for wildlife because they are a critical source of food and sometimes the only source of water in arid landscapes for species such as deer, coyotes and tortoises.
Read more here.
Climate change is eating away at our food systems.
The story: The world’s food systems — from farms to fisheries — are crumbling under climate change. In an interactive feature for The Guardian, Nina Lakhani, Alvin Chang, Rita Liu and Andrew Witherspoon break down how reduced genetic diversity in crops and fish has left supply chains exceedingly vulnerable to climate impacts such as rising temperatures and pest outbreaks.
For example, take bananas. In the early 1900s, agricultural companies found one breed of bananas — known as Gros Michel — to be the most beloved by consumers. From then on, that tasty breed dominated the market.
Here’s the catch: Each of these potassium-filled fruits were genetically identical clones. So when a fungus broke out on banana farms around the United States, the entire supply chain nearly crumbled because there were no immune variations of this species of the fruit.
The big picture: Fortunately for banana-lovers around the world, the industry was able to pivot to a new variety known as the Cavendish, but this breed could soon suffer a similar fate to Gros Michel due to a new fungus cropping up in farms around the country. This shows the importance of increasing genetic diversity in Earth’s food systems while we still have time, The Guardian’s reporters say.
“We made similar mistakes with virtually all industrially farmed foods — optimizing yields and profits while sacrificing diversity,” they wrote. “Cultivating and eating a variety of genetically diverse food would protect us from future pests and diseases.”
Read more here.
As ocean habitats change, so do their sounds.
The story: Climate change is altering the way sounds travel across the ocean, which could have disastrous consequences for marine life, reports Matt Reynolds for Wired. A variety of factors can play a part in how sound spreads across the sea, he writes:
“Sounds are themselves pressure waves, which compress and decompress molecules in the water. When that water is warmer, molecules vibrate faster, allowing sound waves to travel faster. Pressure is higher the deeper you go. Salinity can change too if, say, you’re near a glacier that’s injecting freshwater into the sea.”
Freshwater can dampen sound quality across the ocean, making it difficult for creatures that rely on verbal communication — such as whales and dolphins — to find each other.
The big picture: This climate-induced change in sound quality could also exacerbate the effects of human noise pollution across marine environments, reports show.
Sound can travel underwater across thousands of miles, even further when the water is warmer, which means that marine species can hear the buzz and thrum of virtually every vessel — from massive cargo ships to tiny speedboats — that plies the waters of their habitats. These sounds may seem harmless, but a growing body of research shows that noise can disrupt underwater communication between marine species, potentially affecting breeding, migration and hunting.
Rear more here.
Cover image: A giant cactus in Bolivia (© Alejandro Loayza Grisi)