Guess the replies if you ask if wasps and flies have any virtues. Many people wish them extinct, but they are important pollinators along with wild bees, honeybees, and lepidoptera.
The decline of 1-2% per year in insect populations around the world theoretically reduces agricultural yields. I thought it would be hard to measure the impact, so a paper published this week by the Harvard School of Public Health came as a surprise. The authors estimate pollination failure causes a 3-5% deficit of agricultural productivity in fruit, vegetables, and nuts. The loss of healthy food accounts for 427,000 excess annual deaths.
The data come from experimental farms across four continents monitoring gaps in product yields that depend on pollination. A global disease risk model was applied to estimate the impacts on dietary risks and mortality in different countries.
The economic costs fell mainly on low-income country providers of food. But the health burden fell mainly on middle-income countries, including China and India, because of the relative prevalence of metabolism-related diseases compared to communicable diseases among poor people. The proximate culprits are climate change and loss of biodiversity. We see in our mirrors those ultimately responsible for agricultural shortfalls from disappearing pollinators.
These cute warblers are resident in this region year-round but seen more often in fall and winter when more northerly breeders join their brethren in this warmer clime. As they feed on seeds instead of insects, they don’t need to migrate further for wintering in the sub-tropics.
European Starling murmuration (James Wainscoat: Unsplash)
The United Nations estimates that our population reached 8 billion this week. In 1900, it was 1.6 billion but by the turn of the 21st century, we had grown to over 6 billion. That is nearly 2 billion more mouths than only 22 years ago and the graph is still rising. Meanwhile, most wildlife populations across the globe are plunging. There’s a connection and it’s called the Sixth Great Extinction.
It is harder to estimate populations of birds than terrestrial animals, but North America alone is reckoned to have 3 billion fewer birds than 50 years ago. Seventy species out of a total of over 500 are thought to be close to a tipping point, meaning the threshold for sustaining their presence.
The Cornell Lab for Ornithology released a tool this month that maps trends in the abundance of birds from 2007 to the present. The data were provided by citizen scientists through eBird and mapped in 27×27 km squares (roughly the area of a small county). Birders and gardeners have noticed fewer birds in their localities, especially “common” birds, and this impression now has numbers. Typing the name of any species prompts the map of North America to show the trend in blue boxes for an increase, red for a decrease, and white where it can’t yet be determined with confidence.
I tested the tool for the mid-Atlantic region where I live. The good news is that geese and swans have increased spectacularly, and waterbirds and ducks are doing well too. The protected status of wetlands where there is less pollution and human disturbance is probably responsible.
There are reassuring trends for some raptors (eagles, owls, and the Red-shouldered Hawk) as well as for vultures and ravens. The Pileated Woodpecker, Carolina Wren, Wild Turkey, and Ruby-throated Hummingbird hold up well too.
But the news overall is bleak. Insectivorous species are down from a loss of habitat and prey, a large group that includes warblers and swallows. American Robins and Gray Catbirds are declining, but whatever is responsible hasn’t affected Northern Cardinals that have overlapping habitats. Hearing American Crows every day, I am surprised they are in decline, and will likely appreciate them more if they become rare!
We can do little about the rising human population, but every landowner can help to mitigate the decline in birds by making their property a friendly habitat. This should be easier because few birds are regarded as pests. Many are beautiful and some provide services we appreciate. Farmers can leave field margins fallow for foodplants and insects to thrive. Roadside verges and hedges should be mowed and pruned after the breeding season and boring roundabouts planted with wildflower seeds. Gardeners can set aside corners of their yard for nature to creatively flourish, often as beautiful as a tidy flower bed. Our individual efforts seem paltry against the scale of the problem, but taken together they amount to an area much larger than nature preserves.
If I am around in another 15 years, I am confident of seeing more blue boxes than red on the eBird map if we manage the land differently.
We heard a different owl calling in the woods behind our home today at twilight, not the familiar sound of Barred Owls. It hooted softly, as a tiger might purr to itself, watching a herd of antelopes. It was the so-called Tiger of the Woods.
Click for hooting
Great Horned Owls visit us in the fall but are never heard here in other seasons, although a pair nests in late winter only two miles away on Jamestown Island. They are our largest and most ferocious raptors. Although birds (including other owls), small mammals, and reptiles are their normal fare, they aren’t fussy about what they eat and will tackle prey larger than themselves. Bring your cats and small dogs indoors at night if you hear muted hooting after dark.
Superyacht resembling one owned by a Russian oligarch
As world leaders prepared for COP27 in Egypt, the acclaimed French economist, Thomas Piketty, warned in Le Monde, “It is impossible to seriously fight climate change without profound redistribution of wealth.” He echoed an earlier UN report.
There’s a vicious cycle in which people who are already disadvantaged are disproportionately affected by climate change as they suffer from more inequality. The political headwinds have been going against the socio-ecological left that advocates wealth redistribution. Nationalist governments rise and even Lula’s agenda will be strained by gusts from Brazilian agribusiness interests.
I guess the wealth gap between the super-rich and the rest of humanity is greater today than ever. Piketty blames the Great Recession of 2008 and Covid for widening the gulf. To give it perspective, imagine if a nation the size of Switzerland (8 million and only 0.1% of total humanity) owned 20% of the world’s wealth (equivalent to a year of global GDP). Narrower differences in prosperity have sometimes sparked violent revolutions in history, so we hope for a peaceful transition to greater social justice.
Climate change impacts everyone, but the wealthiest enjoy outsized shares of the world’s goods and are least affected. They can escape disasters in their superyachts and private airplanes to other penthouse suites or chateaux adorned with rare artworks and rest secure with investments spread wide and hidden. The poor are stuck in situ and migration is getting harder for them.
The top benefits for the poor and middle classes from redistributing wealth are education, health, and housing. Investing in human capital will enable them to benefit from clean energy and climate mitigation and reduce their risks from pollution and dangerous occupations. And as child mortality falls in the poorest countries, the incentive to have large families will wane faster.
Unfortunately, Professor Piketty isn’t attending COP27 although he has probably made these points in his chapter of Greta Thunberg’s new climate book.
Roger musing about Peace with Nature 