Category: Environment

The US decline in butterflies

The natural world is quite remarkable!

This article was published in The Conversation last Thursday, the 6th March, 2025.

Where we live in rural Southern Oregon is glorious and photos of our locale have been published before. However, I wanted to share this article with you all.

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Butterflies declined by 22% in just 2 decades across the US – there are ways you can help save them

The endangered Karner blue butterfly has struggled with habitat loss. U.S. Fish and Wildlife Service

Eliza Grames, Binghamton University, State University of New York

If the joy of seeing butterflies seems increasingly rare these days, it isn’t your imagination.

From 2000 to 2020, the number of butterflies fell by 22% across the continental United States. That’s 1 in 5 butterflies lost. The findings are from an analysis just published in the journal Science by the U.S. Geological Survey’s Powell Center Status of Butterflies of the United States Working Group, which I am involved in.

We found declines in just about every region of the continental U.S. and across almost all butterfly species.

Overall, nearly one-third of the 342 butterfly species we were able to study declined by more than half. Twenty-two species fell by more than 90%. Only nine actually increased in numbers.

An orange butterfly with black webbing and spots sits on a purple flower.
West Coast lady butterflies range across the western U.S., but their numbers have dropped by 80% in two decades. Renee Las Vegas/Wikimedia Commons, CC BY

Some species’ numbers are dropping faster than others. The West Coast lady, a fairly widespread species across the western U.S., dropped by 80% in 20 years. Given everything we know about its biology, it should be doing fine – it has a wide range and feeds on a variety of plants. Yet, its numbers are absolutely tanking across its range.

Why care about butterflies?

Butterflies are beautiful. They inspire people, from art to literature and poetry. They deserve to exist simply for the sake of existing. They are also important for ecosystem function.

Butterflies are pollinators, picking up pollen on their legs and bodies as they feed on nectar from one flower and carrying it to the next. In their caterpillar stage, they also play an important role as herbivores, keeping plant growth in check.

A closeup of a caterpillar eating a leaf.
A pipevine swallowtail caterpillar munches on leaves at Brookside Gardens in Wheaton, Md. Herbivores help keep plant growth in check. Judy Gallagher/Wikimedia Commons, CC BY

Butterflies can also serve as an indicator species that can warn of threats and trends in other insects. Because humans are fond of butterflies, it’s easy to get volunteers to participate in surveys to count them.

The annual North American Butterfly Association Fourth of July Count is an example and one we used in the analysis. The same kind of nationwide monitoring by amateur naturalists doesn’t exist for less charismatic insects such as walking sticks.

What’s causing butterflies to decline?

Butterfly populations can decline for a number of reasons. Habitat loss, insecticides, rising temperatures and drying landscapes can all harm these fragile insects.

A study published in 2024 found that a change in insecticide use was a major factor in driving butterfly declines in the Midwest over 17 years. The authors, many of whom were also part of the current study, noted that the drop coincided with a shift to using seeds with prophylactic insecticides, rather than only spraying crops after an infestation.

The Southwest saw the greatest drops in butterfly abundance of any region. As that region heats up and dries out, the changing climate may be driving some of the butterfly decline there. Butterflies have a high surface-to-volume ratio – they don’t hold much moisture – so they can easily become desiccated in dry conditions. Drought can also harm the plants that butterflies rely on.

Only the Pacific Northwest didn’t lose butterfly population on average. This trend was largely driven by an irruptive species, meaning one with extremely high abundance in some years – the California tortoiseshell. When this species was excluded from the analyses, trends in the Pacific Northwest were similar to other regions.

A butterfly on a leaf
The California tortoiseshell butterfly can look like wood when its wings are closed, but they’re a soft orange on the other side. Walter Siegmund/Wikimedia Commons, CC BY-SA

When we looked at each species by its historical range, we found something else interesting.

Many species suffered their highest losses at the southern ends of their ranges, while the northern losses generally weren’t as severe. While we could not link drivers to trends directly, the reason for this pattern might involve climate change, or greater exposure to agriculture with insecticides in southern areas, or it may be a combination of many stressors.

There is hope for populations to recover

Some butterfly species can have multiple generations per year, and depending on the environmental conditions, the number of generations can vary between years.

This gives me a bit of hope when it comes to butterfly conservation. Because they have such short generation times, even small conservation steps can make a big difference and we can see populations bounce back.

The Karner blue is an example. It’s a small, endangered butterfly that depends on oak savannas and pine barren ecosystems. These habitats are uncommon and require management, especially prescribed burning, to maintain. With restoration efforts, one Karner blue population in the Albany Pine Bush Preserve in New York rebounded from a few hundred individuals in the early 1990s to thousands of butterflies.

Similar management and restoration efforts could help other rare and declining butterflies to recover.

What you can do to help butterflies recover

The magnitude and rate of biodiversity loss in the world right now can make one feel helpless. But while national and international efforts are needed to address the crisis, you can also take small actions that can have quick benefits, starting in your own backyard.

Butterflies love wildflowers, and planting native wildflowers can benefit many butterfly species. The Xerces Society for Invertebrate Conservation has guides recommending which native species are best to plant in which parts of the country. Letting grass grow can help, even if it’s just a strip of grass and wildflowers a couple of feet wide at the back of the yard.

Butterflies on wildflowers in a small garden.
A patch of wildflowers and grasses can become a butterfly garden, like this one in Townsend, Tenn. Chris Light, CC BY-SA

Supporting policies that benefit conservation can also help. In some states, insects aren’t considered wildlife, so state wildlife agencies have their hands tied when it comes to working on butterfly conservation. But those laws could be changed.

The federal Endangered Species Act can also help. The law mandates that the government maintain habitat for listed species. The U.S. Fish and Wildlife Service in December 2024 recommended listing the monarch butterfly as a threatened species. With the new study, we now have population trends for more than half of all U.S. butterfly species, including many that likely should be considered for listing.

With so many species needing help, it can be difficult to know where to start. But the new data can help concentrate conservation efforts on those species at the highest risk.

I believe this study should be a wake-up call about the need to better protect butterflies and other insects – “the little things that run the world.”

Eliza Grames, Assistant Professor of Biological Sciences, Binghamton University, State University of New York

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Thank you, Eliza, for promoting this article.

If only one person is inspired to make the changes Eliza recommends then republishing this article has been a success.

Picture Parade Four Hundred and Sixty-Three

Two pictures of the moon!

It was a perfect moment.

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An extended focus shot.

Goodbye Winter

So far as the Northern Hemisphere is concerned.

Just a very short YouTube video.

Venus and Valentine’s Day

The role of the planet today!

From that post: Venus, named for the Roman goddess of love, reaches its greatest brilliancy on Valentine’s Day, February 14. Venus is currently blazing, low in the west after sunset, with Saturn below.

Wherever you are, try spotting Venus.

The Full Moon

The first one of 2025.

The following photograph was taken by yours truly on the 12th January at 17.19 Oregon time.

It was a stunning combination of the moon and the hills and the evening sky.

Picture Parade Four Hundred and Sixty

The balance of the photos taken on the property.

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Picture Parade Four Hundred and Fifty-Nine

A few more photographs of the swollen Bummer Creek.

Firstly, the photo I shared on January 2nd.

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This last one shows how the water, which was up to the bottom of the tree, had the force to hollow out the ground beneath that fine tree!

It is a New Year!

And I want to return to publishing posts!

My last post was about an accident that I had on the 17th November, last.

Jean is now back home; she came home on Friday, 13th December. However, every day we have a caregiver at home for part of the time. Jean is getting slowly better. I would estimate that at about one percent a day.

I am unsure as to the pattern of my posts. Whether I should go back to scheduling posts three times a week or publish posts on an ad-hoc basis. That will become clearer over the next few weeks.

I am going to start with publishing posts on an ad-hoc basis.

Meanwhile here in Merlin we have had loads of rain.

Bummer Creek

This is the creek that flows across the lower part of the property.

The geological history of Planet Earth

We live on a profoundly ancient and beautiful planet.

I follow the photographic website Ugly Hedgehog and have been doing for some time. There has been a post recently from the section Photo Gallery and ‘greymule’ from Colorado called his entry ‘A Couple of Desert Scenes’ and I will display just one of his images from that post.

It makes a wonderful connection to today’s post which is from The Conversation.

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Evidence from Snowball Earth found in ancient rocks on Colorado’s Pikes Peak – it’s a missing link

Rocks can hold clues to history dating back hundreds of millions of years. Christine S. Siddoway

Liam Courtney-Davies, University of Colorado Boulder; Christine Siddoway, Colorado College, and Rebecca Flowers, University of Colorado Boulder

Around 700 million years ago, the Earth cooled so much that scientists believe massive ice sheets encased the entire planet like a giant snowball. This global deep freeze, known as Snowball Earth, endured for tens of millions of years.

Yet, miraculously, early life not only held on, but thrived. When the ice melted and the ground thawed, complex multicellular life emerged, eventually leading to life-forms we recognize today.

The Snowball Earth hypothesis has been largely based on evidence from sedimentary rocks exposed in areas that once were along coastlines and shallow seas, as well as climate modeling. Physical evidence that ice sheets covered the interior of continents in warm equatorial regions had eluded scientists – until now.

In new research published in the Proceedings of the National Academy of Sciences, our team of geologists describes the missing link, found in an unusual pebbly sandstone encapsulated within the granite that forms Colorado’s Pikes Peak.

An illustration of an icy earth viewed from space
Earth iced over during the Cryogenian Period, but life on the planet survived. NASA illustration

Solving a Snowball Earth mystery on a mountain

Pikes Peak, originally named Tavá Kaa-vi by the Ute people, lends its ancestral name, Tava, to these notable rocks. They are composed of solidified sand injectites, which formed in a similar manner to a medical injection when sand-rich fluid was forced into underlying rock.

A possible explanation for what created these enigmatic sandstones is the immense pressure of an overlying Snowball Earth ice sheet forcing sediment mixed with meltwater into weakened rock below.

A hand holds a rock with dark seams through it and other colors.
Dark red to purple bands of Tava sandstone dissect pink and white granite. The Tava is also cross-cut by silvery-gray veins of iron oxide. Liam Courtney-Davies

An obstacle for testing this idea, however, has been the lack of an age for the rocks to reveal when the right geological circumstances existed for sand injection.

We found a way to solve that mystery, using veins of iron found alongside the Tava injectites, near Pikes Peak and elsewhere in Colorado.

A cliff side showing a long strip of lighter color Tava cutting through Pikes Peak Granite. The injectite here is 5 meters tall
A 5-meter-tall, almost vertical Tava dike is evident in this section of Pikes Peak granite. Liam Courtney-Davies

Iron minerals contain very low amounts of naturally occurring radioactive elements, including uranium, which slowly decays to the element lead at a known rate. Recent advancements in laser-based radiometric dating allowed us to measure the ratio of uranium to lead isotopes in the iron oxide mineral hematite to reveal how long ago the individual crystals formed.

The iron veins appear to have formed both before and after the sand was injected into the Colorado bedrock: We found veins of hematite and quartz that both cut through Tava dikes and were crosscut by Tava dikes. That allowed us to figure out an age bracket for the sand injectites, which must have formed between 690 million and 660 million years ago.

So, what happened?

The time frame means these sandstones formed during the Cryogenian Period, from 720 million to 635 million years ago. The name is derived from “cold birth” in ancient Greek and is synonymous with climate upheaval and disruption of life on our planet – including Snowball Earth.

While the triggers for the extreme cold at that time are debated, prevailing theories involve changes in tectonic plate activity, including the release of particles into the atmosphere that reflected sunlight away from Earth. Eventually, a buildup of carbon dioxide from volcanic outgassing may have warmed the planet again.

University of Exeter professor Timothy Lenton explains why the Earth was able to freeze over.

The Tava found on Pikes Peak would have formed close to the equator within the heart of an ancient continent named Laurentia, which gradually over time and long tectonic cycles moved into its current northerly position in North America today.

The origin of Tava rocks has been debated for over 125 years, but the new technology allowed us to conclusively link them to the Cryogenian Snowball Earth period for the first time.

The scenario we envision for how the sand injection happened looks something like this:

A giant ice sheet with areas of geothermal heating at its base produced meltwater, which mixed with quartz-rich sediment below. The weight of the ice sheet created immense pressures that forced this sandy fluid into bedrock that had already been weakened over millions of years. Similar to fracking for natural gas or oil today, the pressure cracked the rocks and pushed the sandy meltwater in, eventually creating the injectites we see today.

Clues to another geologic puzzle

Not only do the new findings further cement the global Snowball Earth hypothesis, but the presence of Tava injectites within weak, fractured rocks once overridden by ice sheets provides clues about other geologic phenomena.

Time gaps in the rock record created through erosion and referred to as unconformities can be seen today across the United States, most famously at the Grand Canyon, where in places, over a billion years of time is missing. Unconformities occur when a sustained period of erosion removes and prevents newer layers of rock from forming, leaving an unconformable contact.

Unconformity in the Grand Canyon is evident here where horizontal layers of 500-million-year-old rock sit on top of a mass of 1,800-million-year-old rocks. The unconformity, or ‘time gap,’ demonstrates that years of history are missing. Mike Norton via Wikimedia, CC BY-SA

Our results support that a Great Unconformity near Pikes Peak must have been formed prior to Cryogenian Snowball Earth. That’s at odds with hypotheses that attribute the formation of the Great Unconformity to large-scale erosion by Snowball Earth ice sheets themselves.

We hope the secrets of these elusive Cryogenian rocks in Colorado will lead to the discovery of further terrestrial records of Snowball Earth. Such findings can help develop a clearer picture of our planet during climate extremes and the processes that led to the habitable planet we live on today.

Liam Courtney-Davies, Postdoctoral Research Associate in Geological Sciences, University of Colorado Boulder; Christine Siddoway, Professor of Geology, Colorado College, and Rebecca Flowers, Professor of Geological Sciences, University of Colorado Boulder

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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All I can add is fascinating.

The summer of 2024 in the Northern Hemisphere.

Once more, an article on the changing climate.

Recently, the BBC News reported that:

Global efforts to tackle climate change are wildly off track, says the UN, as new data shows that warming gases are accumulating faster than at any time in human existence.

Current national plans to limit carbon emissions would barely cut pollution by 2030, the UN analysis shows, leaving efforts to keep warming under 1.5C this century in tatters.

The update comes as a separate report shows that greenhouse gases have risen by over 11% in the last two decades, with atmospheric concentrations surging in 2023.

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What the jet stream and climate change had to do with the hottest summer on record − remember all those heat domes?

Shuang-Ye Wu, University of Dayton

Summer 2024 was officially the Northern Hemisphere’s hottest on record. In the United States, fierce heat waves seemed to hit somewhere almost every day.

Phoenix reached 100 degrees for more than 100 days straight. The 2024 Olympic Games started in the midst of a long-running heat wave in Europe that included the three hottest days on record globally, July 21-23. August was Earth’s hottest month in the National Oceanic and Atmospheric Administration’s 175-year record.

Overall, the global average temperature was 2.74 degrees Fahrenheit (1.52 degrees Celsius) above the 20th-century average.

That might seem small, but temperature increases associated with human-induced climate change do not manifest as small, even increases everywhere on the planet. Rather, they result in more frequent and severe episodes of heat waves, as the world saw in 2024.

The most severe and persistent heat waves are often associated with an atmospheric pattern called a heat dome. As an atmospheric scientist, I study weather patterns and the changing climate. Here’s how heat domes, the jet stream and climate change influence summer heat waves and the record-hot summer of 2024.

What the jet stream has to do with heat domes

If you listened to weather forecasts during the summer of 2024, you probably heard the term “heat dome” a lot.

A heat dome is a persistent high-pressure system over a large area. A high-pressure system is created by sinking air. As air sinks, it warms up, decreasing relative humidity and leaving sunny weather. The high pressure also serves as a lid that keeps hot air on the surface from rising and dissipating. The resulting heat dome can persist for days or even weeks.

The longer a heat dome lingers, the more heat will build up, creating sweltering conditions for the people on the ground.

A 3D image of the US showing a heat dome above it.
High pressure in the middle layers of the atmosphere acts as a dome or cap, allowing heat to build up at the Earth’s surface. NOAA

How long these heat domes stick around has a lot to do with the jet stream.

The jet stream is a narrow band of strong winds in the upper atmosphere, about 30,000 feet above sea level. It moves from west to east due to the Earth’s rotation. The strong winds are a result of the sharp temperature difference where the warm tropical air meets the cold polar air from the north in the mid-latitudes.

The jet stream does not flow along a straight path. Rather, it meanders to the north and south in a wavy pattern. These giant meanders are known as the Rossby waves, and they have a major influence on weather.

An illustration shows how ridges create high pressure to the south of them and troughs create low pressure to the north of them.
Ridges and troughs created as the jet stream meanders through the mid-latitudes create high (H) and low (L) pressure systems. Reds indicate the fastest winds. NASA/Goddard Space Flight Center Scientific Visualization Studio

Where the jet stream arcs northward, forming a ridge, it creates a high-pressure system south of the wave. Where the jet stream dips southward, forming a trough, it creates a low-pressure system north of the jet stream. A low-pressure system contains rising air in the center, which cools and tends to generate precipitation and storms.

Most of our weather is modulated by the position and characteristics of the jet stream.

How climate change affects the jet stream

The jet stream, or any wind, is the result of differences in surface temperature.

In simple terms, warm air rises, creating low pressure, and cold air sinks, creating high pressure. Wind is the movement of the air from high to low pressure. Greater differences in temperature produce stronger winds.

For the Earth as a whole, warm air rises near the equator, and cold air sinks near the poles. The temperature difference between the equator and the pole determines the strength of the jet stream in each hemisphere.

However, that temperature difference has been changing, particularly in the Northern Hemisphere. The Arctic region has been warming about three times faster than the global average. This phenomenon, known as Arctic amplification, is largely caused by the melting of Arctic sea ice, which allows the exposed dark water to absorb more of the Sun’s radiation and heat up faster.

Because the Arctic is warming faster than the tropics, the temperature difference between the two regions is lessened. And that slows the jet stream.

As the jet stream slows, it tends to meander more, causing bigger waves. The bigger waves create larger high-pressure systems. These can often be blocked by the deep low-pressure systems on both sides, causing the high-pressure system to sit over a large area for a long period of time.

A stagnant polar jet stream can trapped heat over parts of North America, Europe and Asia at the same time. This example happened in July 2023. UK Met Office

Typically, waves in the jet stream pass through the continental United States in around three to five days. When blocking occurs, however, the high-pressure system could stagnate for days to weeks. This allows the heat to build up underneath, leading to blistering heat waves.

Since the jet stream circles around the globe, stagnating waves could occur in multiple places, leading to simultaneous heat waves at the mid-latitude around the world. That happened in 2024, with long-lasting heat waves in Europe, North America, Central Asia and China.

Jet stream behavior affects winter, too

The same meandering behavior of the jet stream also plays a role in extreme winter weather. That includes the southward intrusion of frigid polar air from the polar vortex and conditions for severe winter storms.

Many of these atmospheric changes, driven by human-caused global warming, have significant impacts on people’s health, property and ecosystems around the world.

Shuang-Ye Wu, Professor of Geology and Environmental Geosciences, University of Dayton

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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I maybe approaching my own end of life but millions of others are younger than me. When I see a woman with a young baby in her arms I cannot stop myself from wondering what that generation is going to do.