The scale doesn’t lie: Humans’ presence weighs heavily on planet Earth.
Scientists recently calculated the biomass of various lifeforms, and the conclusions were eye-opening.
Land mammals — all the world’s elephants, deer, lions, bears, etc. — have a mass of 22 million tonnes. Humans come in at 390 million tonnes.
Our pets — cats and dogs — have a total mass of 22 million tonnes (20 million of that being dogs). So the biomass of our pets equals the biomass of all wild land mammals.
Here’s the real whopper: Species we’ve domesticated for food and clothing — cattle and sheep — along with “hangers-on” such as urban rodents add up to 630 million tonnes. That’s a 30 to 1 ratio of domesticated to wild.
“We suggest that the ratio between the biomass of wild and domesticated species biomass provides further perspective on the extraordinary increase in humanity’s impact on our planet,” the study’s authors wrote.
Marine mammals fared slightly better — thanks, whales — with a combined biomass of 40 million tonnes.
The point the study’s authors really wanted to drive home, though, goes beyond mere numbers. Among their aims is to disabuse people of the perception of nature as vast and abundant beyond anything humanity creates.
This idea, perpetuated by “natural history movies, textbooks and museums,” has had the effect of decreasing the urgency of nature conservation efforts, the researchers said.
“We tend to internalize ... that the world is enormous and by corollary that natural things ... are seemingly endless,” the authors wrote. “Rigorous estimates of the biomass of various components of the living world, when contrasted to human-associated masses, help dispel these erroneous notions and conclusions.”
Here’s what else caught our attention this week.
Huge tracts of forests are being lost due to demand for agricultural land, and along with the trees goes the biodiversity they support and the carbon they store.
To reduce the conflict between forestry and food, researchers are investigating the potential for forests to serve as non-conventional farms, where the crop would be edible ectomycorrhizal fungi (EMF, aka, mushrooms).
Here’s how it would work: Reforestation projects would inoculate the trees being planted with EMF, which would benefit the soil and also result in mushrooms. The mushrooms could, in turn, be harvested as a sustainable source of protein and calories.
The authors of a recent study say now’s the time to “urgently pursue such options.” Thailand already has projects in progress.
Move over Flaco, there’s another escaped bird making headlines this week.
Meet Oliver, an endangered African black hooded vulture, who flew the coop Tuesday when a falling tree ripped open a hole in his enclosure at the Oakland Zoo.
Oliver hasn’t strayed beyond zoo grounds, but as of Friday, he had eluded attempts to coax him back to the aviary. Keepers have used rat bait and even set out Oliver’s mate in a crate as temptation. So far, Oliver isn’t falling for their tricks.
Unlike Flaco, though, Oliver is short on survival skills. The vulture isn’t a bird of prey and hasn’t been seen eating for days. Zoo officials remain hopeful that Oliver, who was hatched in captivity, will return to his comfort zone.
Japan is testing the limits of the locavore movement with its crop of winter strawberries, so prized by Japanese consumers that individual berries sell for hundreds of dollars, according to this feature in the New York Times.
On the one hand, the fruit is grown locally. On the other hand, the strawberries hit the market in December, having been cultivated in “huge greenhouses heated with giant, gas-guzzling heaters.”
Studies have shown that hothouse local produce actually has a larger carbon footprint than imported seasonal food. Some Japanese farmers are experimenting with alternative heating methods, but simply growing the fruit in warmer months isn’t one of them.
The United States banned the use of DDT in 1972, but the chemical is still polluting the environment.
Vast quantities of the stuff were dumped by its manufacturer directly into the Pacific Ocean near Catalina Island back in the 1940s and ‘50s, and not only is the DDT not breaking down, it’s spreading.
From the Los Angeles Times: “We still see original DDT on the seafloor from 50, 60, 70 years ago,” said UC Santa Barbara scientist David Valentine. “And what we’re seeing now is that there is DDT that has ended up all over the place, not just within this tight little circle on a map that we referred to as Dumpsite Two.”
California condors and local dolphin populations continue to test for high amounts of DDT, and the substance has been linked to an aggressive cancer in sea lions.
Could a fungal disease really spell the end of civilization as we know it, or is the HBO hit series “The Last of Us” just Hollywood science fiction?
White-nose syndrome, a fungal disease, has decimated North American bat populations, killing off 90% of northern long-eared, little brown and tri-colored bats in less than 10 years. The situation is dire enough for the northern long-eared to have been placed on the endangered species list. But there’s a glimmer of hope.
A team at the University of Wisconsin-Madison has been tapped by the federal government to investigate a vaccine that could protect the bats against the disease.
Tweet of the Week
An severe G4 Geomagnetic Storm overnight brought #AuroraBorealis activity to low latitudes enabling rare #NorthernLights views as far south as Madison #WIwx (43 N) and environs. This Day Night Band image shows Aurora shrouding #LakeSuperior and grazing Minneapolis #MNwx (45 N). pic.twitter.com/lrpkjd4SK0
— UW-Madison CIMSS (@UWCIMSS) March 24, 2023
Contact Patty Wetli: @pattywetli | (773) 509-5623 | [email protected]