Category Archives: Climate Change

Planning Ahead for Pittsburgh’s Warmer, Wetter Climate

July 30, 2024Climate Change, TreesKate St. John

Quaking aspen vs Eastern cottonwood (photos from Wikimedia Commons)

30 July 2024

Today in Pittsburgh we’re looking forward to a week of heavy downpours.

HAZARDOUS WEATHER OUTLOOK, Pittsburgh, PA, 30 July 2024
Scattered showers and thunderstorms could produce heavy rainfall that creates localized flooding concerns, favoring low lying or urbanized areas.
— National Weather SErvice Hazardous Weather Outlook for Pittsburgh, PA, July 30 through August 5,2024

It’s hard not to notice that Pittsburgh’s climate is changing fairly rapidly into hotter, wetter weather. Climate predictions indicate that 60 years from now, Pittsburgh weather will feel a lot like McCormick, South Carolina does today.

This is bad news for trees that are on the southern edge of their range. Not only do they live a long time but they cannot adapt as fast as our climate is changing. For example, quaking aspens, which prefer cooler weather, will disappear from Pittsburgh by the end of this century. Meanwhile eastern cottonwoods will do just fine.

Comparing range maps of Quaking aspen vs Eastern cottonwood (maps from Wikimedia Commons)

Pittsburgh’s urban forest and parks are feeling the heat, too. If we do nothing we’ll have fewer and poorer trees in the city 100 years from now.

Fortunately the Pittsburgh Parks Conservancy is planning for our future forest by testing southern tree species at Fezziwig Grove in Schenley Park. Read about the tree nursery project and Kentucky yellowwood, pictured below, at TribLive: Pittsburgh Parks Conservancy forges forest of the future in face of global warming

Kentucky yellowwood flowers, Schenley Park, 20 May 2019 (photo by Kate St. John)

To visit Fezziwig Grove, use the map at this link.

Wondering what our climate will feel like in the future? Check out this vintage article.

What Will Our Climate Feel Like in 60 Years?

If You Think Today is Hot …

July 15, 2024Climate Change, Weather & SkyKate St. John

Deep orange sky, hot sun (photo from Wikimedia Commons)

15 July 2024

Excessive heat from the western U.S. is now in the East and the next two days promise to be brutal.

Right now I’m in Tidewater Virginia where today’s high temperature will be 97°F and “feel like” 107°F. Just after dawn the turkey vultures warmed their wings in my sister’s backyard. I’m sure they know where and how to stay cool later today.

Turkey vultures wake up in Virginia before it’s hot (photo by Kate St. John)

We humans, however, are not always in control of our time and some humans are not as smart as turkey vultures so every newscast reminds us to be careful and stay cool.

Yes, today will be hot but tomorrow will be worse. There will be Extreme Heat even in the mountains of Pennsylvania and West Virginia.

Heat Risk map for 16 July 2024 zoomed in to Eastern U.S. (image from digital.weather.gov)

Fortunately Wednesday will bring relief. Watch the heat for 15-17July on these maps.

Too Hot To Handle!

June 18, 2024Climate Change, Weather & SkyKate St. John

18 June 2024

When a heat dome persisted over the Central US. last August my reaction was “At least it isn’t happening here.” Well, now it is.

U.S. Day 3-7 Hazards Outlook for 20-24 June 2024 from NOAA Weather Prediction Center

A high pressure system that was overheating the Southwest moved in on Monday and put a cap over us that’s circulating hot air and trapping heat at the surface.

Diagram of a heat dome from Wikimedia Commons by NWS/NOAA

Meanwhile there are very few clouds to block the sun. It just keeps getting hotter and hotter. Climate Central says the metro areas of Indianapolis, Cleveland, Detroit, Pittsburgh, Philadelphia, Washington D.C., New York City, and Boston are experiencing:

Record high temperatures from 94°F to 99°F
High humidity that makes it feels hotter when heat index values reach 105°F
Nighttime temperatures never cool below the 70-76°F range.

Pittsburgh’s forecast is all orange.

Heat advisory forecast for 18-21 June 2024 (screenshot from NWS Pittsburgh)

Meanwhile all of us are under stress, especially plants, animals, outdoor workers, people without air conditioning and homeless people.

In addition to all the physical changes, heat makes us irritable, even angry.

Last evening severe thunderstorms knocked out power to more than 100,000 electric customers in southwestern PA. I’m fortunate to have both electricity and air conditioning so I’m staying indoors.

I can hardly wait for it to end.

p.s. US weather maps never show Canada. Did the heat just cease at the border? Nope. It’s hot in Canada, too!

Planted Them Weeks Ago?

May 27, 2024Climate ChangeKate St. John

Cherry tomatoes on the vine (photo from Wikimedia Commons)

27 May 2024, Memorial Day

Pittsburghers used to have a tradition that Memorial Day was the start of outdoor tomato planting season. But if you grow tomatoes today you know that’s not the case. You probably planted them weeks ago.

Just 50 years ago Pittsburgh had an annual average minimum temperature of -10 to 0 degrees F and those numbers didn’t change ten years after this USDA map was produced in 1960.

But the climate is changing rapidly now. Last year USDA officially revised their Hardiness Zones as shown on the 2023 map below.

The Pittsburgh area shifted a 1/2 zone warmer in eleven years. Notice the paler color in the river valleys in Allegheny County on the zoomed map below. Our average annual lowest temperature used to be -5° to 0°F but it jogged 5 degrees warmer. Now it’s 0° to 5° F.

2023 USDA Plant Hardiness zones by zip code (zoomed out)

None of this is a surprise. We were certainly felt hot in April, the warmest on record.

Global temperature anomaly for April 2024 from climate.gov

Air Pollution Makes Pollen Allergies Worse

May 23, 2024Climate Change, Musings & NewsKate St. John

Kentucky bluegrass, Poa pratensis, a common lawn grass in PA (photo from Wikimedia Commons)

23 May 2024

Talk about allergies! Oak tree pollen is finally diminishing in Pittsburgh, but grass pollen allergies are ramping up. I’m allergic to lawn grass. I feel it already.

Red fescue, a common lawn grass in PA (photo from Wikimedia Commons)

A study last year explained why we suffer more in the 21st century. Pollen season is getting worse every year because climate change is lengthening the growing season and increasing pollen production.

Unfortunately, a recent study explains that air pollution makes allergies worse. Pittsburgh has some of the worst particulate air pollution in the U.S.

“Plants that are grown in pollution-stressed situations are known to release more allergens,” says Elaine Fuertes, a research fellow at the National Heart and Lung Institute, Imperial College London.

Depending on the plant species, air pollutants can change the chemical composition of pollen, increasing the potency of pollen allergens and triggering stronger allergic reactions in people. …

…Air pollutants like particulate matter and nitrogen oxides may also make the exine — the outer coating of pollen grains — from some plant species more fragile and, therefore, more likely to rupture into smaller fragments that can penetrate deeper into the lungs.
— Yale Climate Connections: Allergy symptoms got you down? Blame pollen AND air pollution.

Learn more about the interplay between pollen, air pollution and our allergies at Yale Climate Connections article below.

Allergy symptoms got you down? Blame pollen AND air pollution.

BONUS FACTLET: While looking for lawn grass photos I learned that Pennsylvania’s most common lawn grass, Kentucky bluegrass (Poa pratensis), is not native to Kentucky nor to North America. Poa pratensis is from Europe, North Asia and the mountains of Algeria and Morocco.

No Amount of Money Can Stop The Ocean

March 26, 2024Climate Change, Water and ShoreKate St. John

Protective dune washed away at Salisbury Beach, MA as seen 10 March 2024 (photo embedded from Salisbury Beach Citizens For Change on Facebook)

26 March 2024

A decades-old problem became acute his winter. After high winds and a historic high tide damaged 20+ beachfront homes in January at Salisbury Beach, Massachusetts, the residents took up a collection to build a protective dune. It took five weeks, 14,000 tons of sand and more than half a million dollars to build the dune to protect the homes. Three days later it was gone.

Completion of the dune project in early March brought high hopes to Salisbury Beach.

Facebook post by Salisbury Citizens for Change after the dune was completed on 6 March 2024

But in the next three days a natural occurrence, an astronomical high tide, washed it all away.

video embedded from WCVB Channel 5, Boston

The temporary dune did it’s job — no homes were damaged in March — but the idea of spending half million dollars after every storm is out of the question. So the town is regrouping and weighing options.

You might be wondering: Why don’t they just build a seawall?

Seawalls just move the problem a few hundred feet down the beach so they are generally not allowed in Massachusetts (see special exception in yellow).

screenshot from Questions and Answers on Purchasing Coastal Real Estate in Massachusetts at capecod.gov

Also, a seawall will remove the beach entirely as shown in this diagram. If Salisbury Beach builds a seawall they will have no beach at all, just a wall with a sheer drop to the ocean. Understandably, the homeowners want a beach.

Diagram by USACE via Questions and Answers on Purchasing Coastal Real Estate in Massachusetts

The ocean takes land slowly … and then all at once. No amount of money can stop it.

(credits are in the captions)

Will Spring Have a Setback This Weekend?

March 7, 2024Climate Change, Phenology, Weather & SkyKate St. John

Coltsfoot closing at dusk, Schenley Park, 4 March 2024 (photo by Kate St. John)

7 March 2024

Two days ago it was so balmy in Pittsburgh that we wore T-shirts outdoors. The high on Monday 4 March tied the 74°F record, honeysuckle leaves popped out and I found coltsfoot blooming in Schenley Park. The week before was warm, too. Here’s what was blooming Feb 23 to March 1.

The weather is going to turn cold this weekend. Will spring be dealt a setback on Sunday?

In my city neighborhood Saturday night’s predicted low will be 35°F, still above freezing and significantly above normal. The map below shows the low temperature anomaly predicted for this Saturday (Sunday’s map won’t be available until tomorrow). Sunday’s forecast says it will go down to 30°F, barely below freezing.

Predicted low temperature anomaly for Saturday 9 March 2024 (map from Climate Central)

On Monday the weather warms up again. It’ll be 60°F on Tuesday.

I’m not too worried about a Spring setback in the City of Pittsburgh. NOAA’s March 2024 forecast looks pretty hot.

U.S. temperature outlook forecast for March 2024 (map from Climate.gov)

(credits are in the caption)

Hot Weather Affects Maple Sugar Season

February 28, 2024Climate Change, PhenologyKate St. John

Maple sugar bucket hanging on a tree (photo from Wikimedia Commons) — Bucket collecting maple sap to make maple syrup (photo from Wikimedia Commons)

28 February 2024

The month of March is traditionally the best month for tapping maples to collect sap for maple syrup. The sap runs best with daytime temperatures above freezing and nights below freezing. When the days are too hot the sap becomes bitter. When the nights don’t freeze the sap stops running and the season is over.

This winter we’ve had yo-yo weather in the Northeast and Great Lakes states. You can see it in the forecast highs this week from Tuesday 27 Feb through Sat 2 March. The cold front coming through today will result in two nights below freezing. Then temperatures will rise again into the 60s. You can see the new blob of hot weather approaching from the Great Plains on Saturday 2 March.

Maple sugar farmers have had to adjust by starting the season whenever the sap runs — in Pennsylvania that might mean January — and pausing the season when the temperature goes up too high in hopes it will drop again.

This news article from Minnesota shows what their maple farmers are dealing with.

video embedded from KSPT5 Eyewitness News

Right Now You Can Kayak in Death Valley

February 26, 2024Climate Change, Musings & News, Water and ShoreKate St. John

Kayaking on Lake Manly in Death Valley (photo from Wikimedia Commons)

26 February 2024

Solstice Begins the Shortest Season

December 21, 2023Books & Events, Climate ChangeKate St. John

December sunrise in Pittsburgh (photo by Kate St. John)

21 December 2023

When the sun stands still tonight at 10:27pm Eastern Time we’ll experience the shortest day of the year and begin the shortest season as well.

Regardless of the weather we change seasons four times a year based on astronomical events: December solstice, March equinox, June solstice, September equinox. Since these events occur at the same moment everywhere on Earth, each of the four seasons lasts the same amount of time for everyone. This is easiest to see on the Seasons page at timeanddate.com. A screenshot of Pittsburgh at 6am today is shown below.

Current and next seasons in Pittsburgh before the winter solstice (screenshot from timeanddate.com)

If you don’t like winter, the Northern Hemisphere has the best arrangement. Our astronomical seasons from shortest to longest are:

Winter = 88 days, 23 hrs, 39 mins (shortest)
Autumn = 89 days, 20 hrs, 37 mins
Spring = 92 days, 17 hrs, 44 mins
Summer = 93 days, 15 hrs, 52 mins (longest)

Climate change guarantees that winter is the shortest weather season, too. Winter was 21% of the year in 1952 but will take up only 9% of the year by the end of this century.

Average seasonal lengths in Northern Hemisphere, information from Phys.org