Scientists Warn Environmental Threats Could Cascade, Leading to Global System Collapse
Scientists warned last week that multiple overlapping environmental threats to the planet could cascade, leading to a global systemic collapse. A new report based on a survey of over 200 top scientists from more than 50 countries was released by Future Earth, an international research network. Of 30 global risks, the scientists identified the top five as: the climate crisis, extreme weather events, the decline of life-sustaining ecosystems, food insecurity, and water scarcity.
More than one-third of the scientists underlined the threat posed by the interplay and feedback loops among these top five that could worsen one another. For example, extreme weather events like heat waves can accelerate global warming by releasing large amounts of stored carbon from affected ecosystems and at the same time intensify water crises and food scarcity.
In another example, the authors say the loss of diversity of plants and animals weakens the capacity of natural and agricultural systems to cope with climate extremes, increasing our vulnerability to food crises. The scientists especially worry that rising temperatures could tip the planet’s climate system into a self-perpetuating spiral of global warming.
While the report warns of dire consequences, it is remarkably optimistic. The authors write that this is a particularly exciting time to look at these issues. They point to the past year, which has been one of extraordinary social awakening to the hazards of environmental change and demands for action towards a sustainable future. In fact, the authors point out that Oxford Dictionaries chose “climate emergency” as its 2019 word of the year.
A poll by the American Psychological Association supports this optimistic outlook. Fifty-six percent of U.S. adults now say climate change is the most important issue facing society. Sixty-two percent say they are willing to vote for a candidate because of his or her position on climate change.
Bumblebees Are Having Trouble Taking the Heat, But You Can Help
On the topic of biodiversity, the decline of bumblebees in North America and Europe has been dramatic in the last several decades due to the effects of climate change. A study published in the journal Science examined changes in the populations of 66 bumblebee species across the two continents and compared that with climate changes. The findings show that as climate change causes temperatures and precipitation to increase beyond what bumblebees can tolerate, so does their risk for extinction.
In a statement from the University of Ottawa, one of the study’s authors said that bumblebees are the most effective pollinators for crops like tomatoes, squash, and berries. Their results show that we face a future with fewer bumblebees and much less diversity, both in the outdoors and on our plates.
But the authors also suggested things we can do, such as reducing the use of pesticides, planting a diverse array of flowers, and by maintaining habitats that offer shelter, like trees, shrubs, or slopes, that could let bumblebees get out of the heat.
Fireflies at Risk from Habitat Loss, Light Pollution, and Pesticides
Fireflies are also at risk, according to a separate study. Research shows that habitat loss, light pollution, and pesticides threaten the more than 2,000 species of the creatures. The loss of habitat comes from things like converting mangrove areas to palm oil plantations and aquaculture farms in Malaysia.
One of the scientists said in statement from Tufts University that growth of artificial light at night has grown exponentially during the last century, which messes up firefly mating rituals. Many fireflies rely on bioluminescence to find and attract their mates and previous work has shown that too much artificial light can interfere with these courtship exchanges.
Municipal Wastewater Contains Valuable Minerals, Nutrients—and Energy
Wastewater flowing through cities to treatment plants contains vast amounts of energy, in addition to other valuable minerals and agricultural nutrients, and much of these resources could be recovered, according to a new study. Millions of tons of nitrogen, phosphorus, and potassium could be captured from wastewater say researchers from UN University’s Canada-based Institute for Water, Environment and Health. And, if they were, these nutrients could offset more than 13 percent of the agricultural demand for them.
Recovering these minerals would also minimize the amount of nutrients that cause eutrophication—the process by which water becomes enriched, stimulating algal blooms that can choke other aquatic species. Earlier research has shown that human urine accounts for 80 percent of the nitrogen and 50 percent of phosphorus, entering municipal wastewater treatment plants.
In addition to recovering those nutrients, wastewater contains energy in the form of methane—enough to provide electricity to almost 160 million households—roughly the number in the U.S. and Mexico combined. The global volume of wastewater is enormous and is increasing rapidly. By the mid-2030s, it will equal roughly the annual volume flowing through the St. Lawrence River, which drains North America’s five Great Lakes.
Wildfires Can Increase Snowpack—But There’s a Downside
What effect do wildfires have on snowpack? That was the question scientists at Brigham Young University explored. They found there was an 85 percent greater snow depth in forested areas that burned completely, compared to those that didn’t burn at all. According to one of the researchers, fires mean more snowpack initially because of a reduced number of trees that usually block and hold the snow temporarily on branches.
The increased snowpack is good for north-facing slopes where it will hold in the shade. However, it’s not so good with a south-facing slope exposed to the sun. On those slopes a deep snowpack and a rapid spring melt will result in a higher chance of erosion, loss of nutrients, and potential of flooding for downstream communities. And they found that the larger and more severe the wildfire, the increased potential for flooding in valleys.
The study could have considerable implications for water forecasting, especially given that snow from mountain watersheds provides freshwater for over 20 percent of the global human population.
Dogs May Save Your Orange Juice
Fifteen years ago, a scourge arrived in Florida. The state’s famous orange trees became infected by a bacterium (Candidatus Liberibacter asiaticus) that would turn leaves yellow, wilt branches, and produce small, bitter-tasting fruit. Citrus greening disease, also named huanglongbing in China, where it was first discovered, has caused the state’s $9 billion citrus industry, once the second largest in the world, to be on the verge of collapse. From oranges to grapefruits to lemons, no variety of citrus is immune, and the infection has spread to Texas, California, Georgia, and Louisiana, Smithsonian magazine reports.
Currently, the only way to stop the spread of the disease is to eliminate infected trees. But that means spotting an affected plant, which can appear normal for months or even years before succumbing.
So, if you can’t see it, maybe you could sniff it? That was the thought U.S. Department of Agriculture researchers had when they taught 19 dogs including Belgian Malinois, German Shepherds, and Springer Spaniels to pick up the scent of the infection. And after just a few weeks of training in which the animals were taught to sit at a tree where they detected the disease, they were able to identify citrus greening with about 99 percent accuracy. When the dogs worked in pairs, they were nearly perfect.
The dogs also were able to distinguish the citrus greening from a variety of other bacterial, viral, and fungal pathogens, and have alerted the researchers to trees that had yet to test positive in the lab. Dog sleuths are also faster, cheaper, and more accurate than people collecting hundreds of leaves for lab analysis, which so far has a lower rate for confirming the presence of the pathogen. We’ve seen dogs detecting invasive mussels, drugs, explosives, and even finding leaks in water pipes. Orange you glad they’re now in our citrus groves?
Music Credits: The Fixer, Funkygroove | Qin, Dr.Guonake | Jah Moon, Sun Ska Riddim Originale | Scott Holmes, Cat and Mouse | Grégoire Lourme, Rain | Maze, Dark Clouds | Creative Commons
Miss older episodes? Hear all segments from 2020