Light pollution is disrupting the seasonal rhythms of plants and trees, lengthening pollen season in US cities

July 17, 2022 / activist360

By Yuyu Zhou, The Conversation (CC BY-NC-ND 4.0).

The big idea

City lights that blaze all night are profoundly disrupting urban plants’ phenology – shifting when their buds open in the spring and when their leaves change colors and drop in the fall. New research I co-authored shows how nighttime lights are lengthening the growing season in cities, which can affect everything from allergies to local economies.

In our study, my colleagues and I analyzed trees and shrubs at about 3,000 sites in U.S. cities to see how they responded under different lighting conditions over a five-year period. Plants use the natural day-night cycle as a signal of seasonal change along with temperature.

We found that artificial light alone advanced the date that leaf buds broke in the spring by an average of about nine days compared to sites without nighttime lights. The timing of the fall color change in leaves was more complex, but the leaf change was still delayed on average by nearly six days across the lower 48 states. In general, we found that the more intense the light was, the greater the difference.

Chart: The Conversation/CC-BY-ND Source: Meng, et al. 2022 Get the data Download image

We also projected the future influence of nighttime lights for five U.S. cities – Minneapolis, Chicago, Washington, Atlanta and Houston – based on different scenarios for future global warming and up to a 1% annual increase in nighttime light intensity. We found that increasing nighttime light would likely continue to shift the start of the season earlier, though its influence on the fall color change timing was more complex.

Why it matters

This kind of shift in plants’ biological clocks has important implications for the economic, climate, health and ecological services that urban plants provide.

On the positive side, longer growing seasons could allow urban farms to be active over longer periods of time. Plants could also provide shade to cool neighborhoods earlier in spring and later in fall as global temperatures rise.

But changes to the growing season could also increase plants’ vulnerability to spring frost damage. And it can create a mismatch with the timing of other organisms, such as pollinators, that some urban plants rely on.

*Urban light intensity varies among cities, and among neighborhoods within cities. Yuyu Zhou, CC BY-ND*

A longer active season for urban plants also suggests an earlier and longer pollen season, which can exacerbate asthma and other breathing problems. A study in Maryland found a 17% increase in hospitalizations for asthma in years when plants bloomed very early.

What still isn’t known

How the fall color timing will change going forward as night lighting increases and temperatures rise is less clear. Temperature and artificial light together influence the fall color in a complex way, and our projections suggested that the delay of coloring date due to climate warming might stop midcentury and possibly reverse because of artificial light. This will require more research.

How urban artificial light will change in the future also remains to be seen.

One study found that urban light at night had increased by about 1.8% per year worldwide from 2012-2016. However, many cities and states are trying to reduce light pollution, including requiring shields to control where the light goes and shifting to LED street lights, which use less energy and have less of an effect on plants than traditional streetlights with longer wavelengths.

Urban plants’ phenology may also be influenced by other factors, such as carbon dioxide and soil moisture. Additionally, the faster increase of temperature at night compared to the daytime could lead to different day-night temperature patterns, which might affect plant phenology in complex ways.

Understanding these interactions between plants and artificial light and temperature will help scientists predict changes in plant processes under a changing climate. Cities are already serving as natural laboratories.

Feed humans before livestock – World Wildlife Fund

July 10, 2022 / activist360

Transform UK farmland to boost food resilience and tackle nature crisis, says WWF.

By, Brendan Montague, The Ecologist (Creative Commons 4.0)

Half of the UK’s wheat harvest each year – equivalent to 11 billion loaves of bread – is being used to feed livestock in an “inherently inefficient” process that is fuelling climate change, a WWF report reveals.

The report shows the extent of farmland used to grow crops that are being used to feed animals instead of people. It explores the benefits for people, climate and nature of using more of the UK’s arable land to grow crops for human consumption instead, such as addressing the climate and nature crises and boosting the UK’s food resilience.

The latest report in WWF’s Future of Feed series highlights the fact that dairy and meat products provide only 32 percent of calories consumed in the UK and less than half of protein despite livestock and their feed making up 85 percent of the country’s agricultural land use.

Habitats

Growing crops like cereals to feed farm animals accounts for a significant proportion of this land-use footprint, according to the analysis in the report.

Wheat and barley grown to feed farmed animals in the UK using 2 million hectares of land – 40 percent of the UK’s arable land area.

Wheat grown in the UK each year to feed livestock – mostly chickens and pigs – makes up half of our annual wheat harvest and would be enough to produce nearly 11 billion loaves of bread.

Oats grown in the UK to feed livestock each year make up a third of our annual oat harvest and would be enough to produce nearly 6 billion bowls of porridge.

The UK imports large quantities of soy to feed pigs and poultry, fuelling the destruction of precious habitats overseas, like the Brazilian Cerrado.

Affordable

Replacing animal feeds like soy and cereal with alternatives like grass, by-products from the food supply chain, and innovative feed ingredients such as insect meal, would free up land to grow food for people, including high-value crops like fruits, vegetables, and nuts, and could be at the heart of a transition to nature-friendly regenerative agriculture.

The report recognises that this approach to feeding farm animals would necessitate a reduction in the overall numbers of livestock in the UK.

Kate Norgrove, executive director of advocacy and campaigns at WWF said: “We can’t afford to stay locked into a food system that’s not fit for purpose, with food prices soaring.

“Far too much of the food we eat is produced in ways that are fuelling the climate crisis and driving catastrophic nature loss, yet failing to deliver affordable, healthy food for all.

Biodiversity

“To make our food system truly shock-resistant we need to accelerate a shift to sustainable production, including rethinking the way we are using huge quantities of the UK’s most productive land to grow food for livestock instead of people.

She added: “UK governments can future-proof our food and bring huge benefits for nature and climate at the same time by ramping up support for farmers to transform our landscapes, making space for nature in farms and forests, fields and fens.”

Focusing purely on the carbon footprint of food production risks fuelling agricultural intensification and masking other negative environmental impacts, like pollution from the slurry or land conversion for feed production in chicken farming, which can have a low carbon footprint in comparison with pasture-fed beef, the report states.

It also highlights the importance of looking at a wider range of measures to evaluate the environmental impact of all aspects of food production, taking account of pressures on land, water, and biodiversity before drawing conclusions.

Does Supreme Court decision doom power plant rulemakings?

July 3, 2022 / activist360

*Greta Thunberg (weißes T-Shirt und Megaphon mitte-rechts) und Luisa Neubauer (daneben in Grün) im Demonstrationszug von Fridays For Future, Berlin, 24.09.21*

‘Seismic decision’ in landmark climate ruling, CNN says in reporting on decision written by Chief Justice Roberts

By Bud Ward, Yale Climate Connections (CC BY-NC-ND 2.5)

Devastating.” “Hamstrings …” “… a major blow …” “destructive …” a cataclysm …”

And more.

Those are a few of the early terms used by proponents of greenhouse gas emission regulation to describe the U.S. Supreme Court’s June 30 decision in the most significant environmental case of its session … and perhaps since the Court’s ruling in 2007 finding carbon dioxide a public health pollutant subject to regulation under the Clean Air Act.

In its final decision of this consequential term, the court’s now-familiar six-to-three conservative majority ruled EPA had gone beyond its legal authority by attempting to regulate greenhouse gases through the Obama-era Clean Power Plan. The decision was written by Chief Justice John Roberts, with the three progressive justices dissenting.

But the decision did leave the door slightly ajar to Congress’s outright authorization of such regulations somewhere down the highly uncertain road ahead. Critics of the court’s ruling in West Virginia v. EPA found that option highly unlikely politically and, in any event, nothing to celebrate.

Private sector, market forces, big business left to take climate leadership roles? (to be determined)

“Devastating” is the term the Biden White House used in its initial take on the decision.

Carol Browner, EPA Administrator during the Clinton administration, not surprisingly, used the same term in an interview with CNN, which labeled the ruling a “big blow” to Biden administration climate change ambitions. The decision is expected by many to have implications extending far beyond EPA and climate, affecting rule making by diverse Executive branch agencies (the “administrative state”) on a wide swath of issues.

Upcoming posts coming soon at this site will provide detailed coverage on the court’s ruling; on reactions to the ruling from legal and policy experts; and on what options the federal government, and perhaps some states, might next consider in attempting to reduce greenhouse gas pollutant emissions and atmospheric concentrations.

Forecast ahead: Lots of uncertainty, lots more case-by-case litigation, further doubts over U.S. global role, let alone “leadership,” on climate change.