Category Archives: Climate Change

High Tide On The Allegheny

High water at Highland Park Dam, 11 July 2019, 4pm (photo by Kate St. John)

Yesterday morning heavy rain caused flash floods, road closures, landslides, basement and first floor flooding, and car accidents in Pittsburgh.

The rain gauge at the airport measured 2.32″ for the day. All but .01″ of it fell in just four hours.

Precipitation at Pittsburgh International Airport, 11 July 2019 (graph from National Weather Service)

There were three huge rain events so thick that you couldn’t see to drive.

  • Half an inch (0.53″) in 50 minutes, 7:05a-7:50a
  • More than a third of an inch (0.38″) in 25 minutes, 7:55-8:17a
  • 1.4 inches in an hour, 10:05a-11:05a

If you want to see what it was like, click here for great footage from WPXI.

Hours later, at 3:30pm, a friend and I made our way from Indiana Township (between Fox Chapel and Cheswick) to Churchill. It took over an hour to get there. The traffic was horrendous and the roads that were open were littered with debris. Nadine, Sandy Creek, and Washington Boulevard were all closed.

But I got two photos of the river in flood.

High tide on the Allegheny!

p.s. This rain didn’t even set a record at the airport though there may have been localized records. My friend Julie had 4″ in her rain gauge in her Squirrel Hill backyard. Sue Vrabel commented below that she had 4.5″ in Churchill.

(photos by Kate St. John, rain graph from the National Weather Service)

Incredibly Hot in Alaska

Alaska high temperature forecast for 7 July 2019 (map from National Weather Service)

Don’t be fooled by the happy green colors on the watery edge of this map. The high temperature in much of Alaska tomorrow will be 85 degrees F.

Alaska is baking under a five-to-seven day heat wave caused by exceptionally strong high pressure that will break most temperature records. Alaskans aren’t prepared for it. The normal high in Anchorage this week should be 67 degrees F but that’s close to what the low will be (61).

The deepest red on the map is in the southwest interior near the Kuskokwim River where the temperature will soar up to 95 degrees. This area suffered last winter, too, when an early thaw shut down transportation to 13,000 people.

Not only will it be hot in Alaska but it will be hard to breathe. Baking temperatures, dry vegetation and lightning have ignited huge forest fires across the state. The Sunday 7am forecast for much of Alaska includes “areas of smoke” shown in gray below.

Alaska Predominant Weather forecast for 7 July 2019 (map from National Weather Service)

There’s only one place left that’s truly cold. That cold dot on the map is the peak of Denali.

Where is it cold in Alaska?

(maps from the National Weather Service; click on the captions to see the graphical forecast for Alaska)

Beat The Heat With Trees

It’s been hot in Pittsburgh lately but nothing like the heat wave that’s sweeping Europe with highs above 100 degrees F. @JeremyDBarrell tweeted a long term solution with a compelling image by Meg Caffin.

Meg Caffin is an urban forest consultant from Australia who provides guidance for cities looking to beat the heat. Her image at top used an infrared camera to show the temperature difference between a paved churchyard and the trees behind it. I’ve made a Fahrenheit translation below. Yes, it’s 113oF on the pavement and only 77oF under the trees.

Tree shade is cooler than building shade because buildings merely block the sun while the trees actually lower the temperature.

Schenley Park near Bartlett entrance (photo by Kate St. John)

Trees cool the air by transpiring. They take up water from the ground and release it from the stomata in their leaves. The release doesn’t usually drip from the leaves as shown below. Instead it evaporates and that’s what cools the air.

Transpiration droplets from a leaf (photo from Wikimedia Commons)

Evaporation — changing a liquid to a gas — uses energy. According to the Transpiration blog, “Energy is absorbed into liquid water. This reduces the temperature of the surrounding plant tissue and nearby atmosphere. To evaporate 1 gram of water 590 calories of energy is required.”

So more trees mean less heat.

If that isn’t enough reason to like trees, here’s another benefit. Trees increase your property value as shown in the EPA cost-benefit analysis below.

Trees increase property value far beyond cost of maintenance (EPA)

Plan to plant a tree this fall or plan to keep one. It’s cheaper to keep an existing tree than to plant a new one and mature trees increase property value even more.

Meanwhile if you’re feeling hot right now, visit a local park.

Schenley Park Upper Trail, July 2017 (photo by Kate St. John)

Beat the heat among the trees.

(embedded Tweet from Jeremy Barrell; infrared heat image by Meg Caffin for the City of Geelong, Australia (Fahrenheit added); transpiring leaf from Wikimedia Commons; photos of Schenley Park by Kate St. John)

The Poster Child For Climate Change

Surface air temperature patterns across the Arctic in 2018 (map from climate.gov, annotated to show Alaska)

Alaska Birding with PIB: Arrive in Nome, 20 June 2019

Because the Arctic is warming twice as fast as the rest of the planet, Alaska copes with climate change every day.

Record heat waves, low sea ice, eroding coastlines, melting permafrost, disappearing lakes, ice-road failures, and declines in fish, bird and wildlife populations. Here are just a few examples of what Alaska is dealing with:

Ice road failures:

An ice road in Alaska, dog sled on the berm (photo from Wikimedia Commons)

Winter is the time to go places in Alaska when the frozen lakes and rivers become highways, but this year the ice was thin and it broke up earlier than expected. There were accidents at the ice failures, people died, and villages were cut off because the ice is their only road. Every winter the Kuskokwim River becomes a 200-mile ice highway that links 13,000 people in southwestern Alaska. The New York Times described how people cope now that the ice is thin: Alaska Relies On Ice. What Happens When It Can’t Be Trusted?

Lack of sea ice makes a village disappear:

Aerial view of Shishmaref, Alaska (photo from Wikimedia Commons)
Erosion at Shishmaref, Alaska, 1950-2012 (map from Wikimedia Commons)

The town of Shishmaref, Alaska is disappearing. Perched on an island in the Chukchi Sea, the sea ice that used to protect it from huge waves in autumn storms is forming too late now to do any good. The new seawall is a only temporary fix. The island is shrinking. In 2016 the villagers voted to leave the island but there’s no money to do it — and so they stay. Read more + video at CNN’s Tragedy of a village built on ice.

Wildlife declines, seabird die-offs:

Caribou in Alaska (photo from NPS Climate Change Response on Flickr)

An international study of reindeer and caribou across the Arctic shows that almost all of the herds are in decline: 2018 Arctic Report Card: Reindeer and Caribou continue to decline.

In PLOS One, a recent study of a massive seabird die-off in 2016 indicates that unusually warm ocean temperatures lowered the food supply and lead to starvation for 3,100 to 8,800 seabirds, especially tufted puffins. This group washed ashore at St. Paul Island, Bering Sea in October 2016.

Seabird carcasses found on North Beach, St. Paul Island, Alaska, 17 October 2016 (photo from PLOS One)

Thawing permafrost, combustible lakes:

Thawing permafrost causes many problems. When the frost melts the land slumps and slides. This slump engulfed trees and created new cliffs.

New cliffs and delta, 1000 feet long, as permafrost thaws into the river (photo from Wikimedia Commons)

When the land subsidies, trees collapse and die (called drunken trees). The area becomes a bog.

Trees die, bogs form as permafrost thaws, Innoko NWR, Alaska (photo from Wikimedia Commons)

Methane formerly trapped in the permafrost bubbles up in lakes (photo) with potentially explosive results (video).

Methane bubbles in a frozen lake, Alaska (photo from Wikimedia Commons)

Alaska is experiencing so many effects of warming that it could be a poster child for climate change.

(photos from Wikimedia Commons; click on the captions to see the originals)

p.s. Yesterday on the boat trip at Kenai Fjords National Park we saw some of the glaciers in this news article, especially Northwestern Glacier: https://www.cbsnews.com/pictures/repeat-photography-of-alaskan-glaciers/

Is It Spring Yet?

Honeysuckle leaves in the City of Pittsburgh, 16 March 2019 (photo by Kate St. John)

20 March 2019

Today is the astronomical First Day of Spring when the sun crosses the celestial equator at 5:58pm EDT. But is it Spring yet? It depends on where you live.

The USA National Phenology Network tracks spring across the continental U.S. based on first leaf out conditions for honeysuckle (Lonerica) and first bloom conditions for lilacs (Syringa vulgaris). The plants are non-native, and honeysuckle is invasive, but they make good indicators because they’re early responders to springtime warmth.

Monday’s animated Spring Leaf Index (18 March 2019) shows that leaf out was ahead of schedule through late February but fell behind in northern Virginia, the southern Great Plains, and the Pacific Northwest when cold weather hit in early March.

Spring Leaf Index as of 18 March 2019 (animation from USA NPN)

According to the model, spring hasn’t reached Pittsburgh yet but I’m conducting my own Leaf Out Survey in my neighborhood. I took the honeysuckle photos below on 11 March and 16 March 2019. Both were cold days after a spurt of exceptionally warm weather. The tiny leaves on the right show the effect of 77 degrees F on March 14!

Honeysuckle leaf out, City of Pittsburgh, 11 March and 16 March 2019 (photos by Kate St. John)

Do you have leaves in your neighborhood yet? Is spring on time?

Follow spring’s progress at the USA National Phenology Network. For blooming times click here for the latest Spring Bloom map.

(animated map from the USA National Phenology Network. photos by Kate St. John)

Extinction Capital of the World

  • Kioea. Last seen in 1859.

By now in my series on Hawaii you’ve probably noticed that the rarest birds on the islands are threatened with extinction. Sadly this situation is normal. So many Hawaiian species have gone extinct and so many are on the edge today that Hawaii is known as the Extinction Capital of the World. The group of forest birds called Hawaiian honeycreepers are a case in point.

Five million years ago a flock of finches similar to redpolls (Carpodacus erythrinus) arrived from Asia, flying non-stop for more than 4,000 miles. When they arrived, Oahu and the Big Island didn’t exist, but over millions of years they spread out and evolved into 59 species of Hawaiian honeycreepers with a wide variety of beaks for exploiting Hawaii’s food sources. They diversified more than Darwin’s finches.

Each bird was perfectly evolved to survive Hawaii’s dangers but had no defense against off-island threats. Their exposure came with the arrival of humans. We came in two waves.

Polynesians arrived in Hawaii around 400AD and were here alone for 1,400 years. During that period 30% of the Hawaiian honeycreepers went extinct.

In 1778 Captain James Cook was the first European to see Hawaii, prompting immigration from the rest of the world. Since then, in just 240 years, another 39% of the honeycreepers have gone extinct. 18 species remain but six are so critically endangered they may be gone soon.

The slideshow above shows a fraction of what we’ve lost. The last bird, the black-faced honeycreeper or poo’uli (Melamprosops phaeosoma), is still listed as critically endangered with 1 to 49 individuals left on Earth. However, none have been seen since 26 November 2004. It’s probably gone.

Hawaii’s endemic birds go extinct so easily because of …

  • Habitat loss: Humans cleared the forest for settlements. Some species had such a small range or specialized food that when their patch was gone, they were too.
  • Introduced species, especially rats, cats and mongoose: The birds don’t know to move their nests out of reach.
  • Avian malaria and avian pox: Honeycreepers have no immunity.
  • Mosquitoes: Avian diseases, carried by mosquitoes, arrived with introduced birds. Honeycreepers don’t know to brush mosquitoes away. They catch malaria easily and it kills them.
  • Climate change: There’s safety from mosquitoes at high elevation but climate change is heating the mountains. The mosquitoes are moving uphill.

Avian diseases caught from mosquitoes are the big problem. Fortunately there’s a silver lining. One of the honeycreepers, the Hawai’ian amakihi, can now live with avian malaria and is expanding its range within mosquito territory.

This 27-minute video, made in 2005 by Susanne Clara Bard, tells the story of the Hawai’ian amakihi’s survival. Though this video is a lot longer than I normally post, it’s worth even a short look to learn why Hawaiian birds face so many challenges.

The Hawai’ian amakihi evolved to survive malaria in only 200 years.

(images from Wikimedia Commons; click on the links to see the species account at Wikipedia)

Tour Day 9: Leaving the Big Island of Hawai’i for home

What Will Our Climate Feel Like in 60 Years?

Clouds in hot summer (Creative Commons license on Flickr)

We know our climate is changing compared to 30 years ago because we see obvious signs:

Science predicted this more than a generation ago, but most of us couldn’t imagine how it would feel. Now that we’ve seen 30 years of change and more is in store, we’re anxious to know what our climate will be like in the future.

Matt Fitzpatrick and his colleagues at the University of Maryland Center for Environmental Science have answered this question by visualizing the future on an interactive map. Their study analyzes 540 cities in the U.S. and Canada, mapping their predicted climate in the 2080s to an existing climate today.

I tried out the map for myself at https://tinyurl.com/urbanclimate. I looked up Pittsburgh, PA of course and got the answer shown in the screenshot below.

It shows that Pittsburgh’s 2080 climate will feel like Jonesboro, Arkansas does today. Jonesboro is 665 miles away from here, near Memphis, Tennessee. (Click on the image to see the website. Use website controls to see more complex answers.)

What will Pittsburgh’s climate feel like in 60 years? (screenshot of climate prediction at tinyurl.com/urbanclimate)

The map bubbles explain: Our winters will be 10.8F warmer and 46.8% wetter. Our summers will be 10F warmer and 17.6% drier.

Let’s compare current to future using graphs. Pittsburgh’s current climate averages are shown below from U.S. Climate Data.

Sixty years from now our average winter lows will barely reach freezing. July and August average highs will be 93+ degrees F but watch out for the highest highs. August record temperatures in Jonesboro are all above 103oF!

Graph comparing current average high/low temperatures by month to 2080 prediction, Pittsburgh, with 100+ degrees maximum (graph by Kate St. John using current averages, adding UMCES prediction)

Our precipitation will be really different. We’ll go from a fairly steady 3 inches of rainfall per month to a rainy season in November-to-May and a dry season June-to-October. This might resemble California’s wet (flood) and dry (fire) seasons.

Graph comparing current average rainall by month to 2080 prediction for Pittsburgh (graph by Kate St. John using current averages, adding UMCES prediction)

Try the app for yourself at https://tinyurl.com/urbanclimate.

We’re in for a wild ride.

For more information read about the study here at University of Maryland Center for Environmental Science.

(credits: Cloud photo from Flickr, Creative Commons license. Map screenshot from https://tinyurl.com/urbanclimate. Pittsburgh current climate graph from U.S. Climate Data. Graphs of Pittsburgh’s future temperature and rainfall by Kate St. John. Click on the captions to see the originals)

Island Disappears In Rising Seas

Location of Dogger Bank (image from NASA via Wikimedia Commons)

Climate change is giving us extreme weather, melting glaciers and rising seas. It’s not the first time we humans lived through this but the last event was during the Stone Age and nobody wrote it down.

During the last Ice Age England was connected to Europe. As the glaciers receded people moved to the land between. Dogger Bank was the highest ground, about 100 feet above sea level.

100 feet sounds like a safe height, right? Nope. The glaciers kept melting. Dogger Bank disappeared 8,200 years ago.

Many islands face this fate in the 21st century including Tangier Island, Virginia (map below) and the island nations of Kiribati and the Maldives with 100,000 to 400,000 residents respectively.

Location of Tangier Island, Virginia, threatened by sea level rise, via Google maps
Sunset in the Maldives (photo from Wikimedia Commons)

Like Dogger Bank they’re going underwater. Read more in this vintage article about Dogger Bank In the Age of Rising Seas.

(photo from Wikimedia Commons; click on the caption to see the original)

Wobbly Jet Stream, Arctic Air

Low temperature forecast maps, 27 Jan to 2 Feb 2019, from National Weather Service as of 27 Jan 2019, 5:30a.

Remember how cold it was in January 2014? It’s been five years since we saw extremely cold weather but the jet stream is wobbling again and we’re going to see a smack of subzero temperatures this week. The maps show this week’s forecast lows described by the National Weather Service:

Bitter cold temperatures will give way to a potentially record breaking push of Arctic air this week. Wind chills as low as -40 or colder can be expected across the Northern Plains and Great Lakes. In addition, wide swaths of heavy snow can be expected across the area. This system will push east and south early this week with much below normal temperatures and wintry precipitation.

National Weather Service, 27 Jan 2019, 5am

Crazy as it seems, extreme cold is a sign of climate change. Here’s an explanation from my Polar Vortex article of January 2014:

“In the good old days before climate change, the winter polar vortex in the northern hemisphere was generally well behaved.  It was a persistent, strong, cold, low pressure zone surrounding the polar high at roughly the same latitude around the globe.  The strong winds kept the jet stream in line.  Nobody got too hot or too cold.

“But now as the Earth gets hotter hot air from the troposphere is forced into the stratosphere and disrupts the polar vortex. The vortex weakens, becomes disorganized, and can collapse into smaller pieces.  Its winds weaken and the jet stream flaps like a flag in the breeze, as shown in (c) below.”

Jet stream Rossby waves (graphic from Wikimedia Commons)
Jet stream Rossby waves (graphic from Wikimedia Commons)
  • (a) Strong polar vortex (blue) keeps jet stream (pink) at same latitude.
  • (b) Polar vortex weakens
  • (c) Weak vortex lets the jet stream range widely north and south.

Get ready! Arctic air is on its way.

(forecast maps from the National Weather Service. jet stream diagram from Wikimedia Commons; click on the captions to see the originals)

The 100th Meridian Is Moving East

North Dakota, riparian wildlife habitat (photo from USDA)

The 100th Meridian West is an imaginary line on the map that happens to mark the climate divide between the humid east and arid west in North America. Or rather, it used to. The rainfall divide is moving east.

Extending from the North to South Poles, the 100th runs longitudinally in the U.S. from North Dakota through Texas.

The 100th meridian is on the upright border of Oklahoma and Texas (image from Wikimedia Commons)

Its coincidence with the rainfall divide was first documented in 1877 by John Wesley Powell who found during his explorations in the Great Plains that the 100th was a visible boundary. Locations to the east of the 100th received 20+ inches of annual rainfall, the west received less.

20 inches is a key number for agriculture and human population. It determines what you can grow, whether you have to irrigate and, thus, how many people can live there. Powell saw the line and told Congress it had implications for settlement of the western plains. Congress didn’t heed him but …

This 2014 map of U.S. Population by County shows that it played out as Powell expected. You can see the rainfall divide in population density. People choose to live where there’s water.

U.S. population by county, 2014 (map from US Forest Service)

You can also see the line from outer space. I’ve marked the 100th (approximately) on this satellite photo of Nebraska. The landscape is deep green to the east though not uniform.

Satellite photo of Nebraska shows it is drier west of the 100th (photo from Wikimedia Commons)

Nowadays the 100th is no longer the rainfall divide.

A study by Columbia University meteorologists found that the aridity line has shifted 140 miles east and is now statistically located at the 98th meridian. Climate change will move it even further as warming evaporates moisture in the northern plains and alters rainfall in the south.

In a hundred years the aridity mark may be firmly inside Minnesota, Iowa and Missouri. Aridity decreases the amount of agriculture and will probably change the population. People choose to live where there’s water.

John Wesley Powell’s “100th meridian” is moving east.

This article was inspired by Yale Climate Connections. Read more here in Yale Environment 360, 11 April 2018.

(photos from USDA, USFS and Wikimedia Commons; click on the captions to see the originals)