American letter | The death of cacti and people

(Phoenix, Arizona) Archer Shelton has been explaining the life of cacti to me for a few minutes now.

“Let us put ourselves in the shadow of this palo verdeif you please,” the Phoenix Botanical Garden volunteer told me, wiping his forehead under his official gardener’s hat.

“It’s the official tree of Arizona, notice the green bark, it’s its technique for producing chlorophyll even during droughts. See its tiny leaves, it’s another adaptation to the desert heat, isn’t it beautiful? »

Summer may still be far away, but it was 38 degrees on Saturday and everyone who lives in Phoenix has its own adaptation technique.

But even for desert plants, there are limits beyond which they suffocate. Last summer, dozens of Saguaro, Arizona’s iconic majestic cactus, died at the botanical garden. Plants mostly around a hundred years old.

So much in a single summer was unheard of.

Experts now rank the Saguaro among the most endangered plants in the world due to climate change.

It must be said that 2023 has been brutal. In total, 54 days above 110 degrees Fahrenheit (43 degrees Celsius). Including 31 in a row in the heart of summer. Which means days at 45, 46, 47 degrees…

We approach a cactus. Mr. Shelton gives me an accordion look around the exterior. The plant contracts and expands depending on the temperature and the quantity of water stored. It is superbly equipped for the heat. But she needs respite, and even when it’s above 32 degrees at night, she’s having a hard time. Hence this horticultural massacre.

Humans are also increasingly dying from heat in Phoenix. There have been 645 reported “heat-related” deaths in 2023 in Maricopa County, which includes the city. This was 50% more than the record set in 2022 (425), which itself far exceeded the previous year in mortality (339).

Who dies ? Especially homeless people. Or too poor to have air conditioning. Or have it repaired. Older people, sick too.

You can’t do almost any outdoor activity at this temperature.

Many of these deaths reflect the opioid and housing crisis. Losing consciousness at 20 degrees Celsius or 45 obviously does not have the same consequences.

Doctors speak of a public health crisis; heat, even linked to intoxication, now causes as many deaths as road accidents.

Three years ago, the City of Phoenix opened a heat mitigation office. Which means in particular opening air-conditioned shelters. But also better adapt town planning. Poor urban design is itself a factor in heat concentration.

The City has announced its desire to massively increase the plant cover, by planting large quantities of trees. Obviously, this will require water, in a city where the population is growing rapidly. And in a state that is in the middle of negotiating its portion of water from the Colorado River, which irrigates seven American states, and immense thirsty agricultural lands.

“I had lived in Phoenix for 20 years when I came to the Botanical Garden one March day in 2007 with visiting friends,” said Archer, a retired mining industry veteran. It was magical. There were flowers everywhere, the smell was incredible. It opened my eyes to the beauties of desert plants. It’s like I’ve been looking out a window at the desert for 20 years without really seeing it. »

As he talks to me, a cactus wren passes behind us and takes up residence in a Saguaro hole.

“It seems it’s cooler in there…”

The week after that 2007 visit, Archer Shelton asked to volunteer at the garden. The following week, he convinced his wife to rip up the grass in the yard and grow native plants.

“Until then, our idea of ​​a garden was a green lawn that was constantly watered. But look around us. It’s much more beautiful. Now our yard is spectacular, and contains only desert plants. More and more people are abandoning the classic Bermuda grass, which really isn’t made for Arizona. »

In the dry river of problems, this may seem like a drop. But every drop counts in this state.

Archer loves all cacti, but the king is still the Saguaro. It is the subject of intensive poaching, a crime which carries heavy fines and prison. So far, this is the biggest threat to the green symbol of the Sonoran Desert. But successive heat waves will cause more and more of them to fall into the sun.

“There are millions of them in the desert, so everything seems normal. But when you’re on the edge of the precipice and you don’t know it, everything seems normal too, doesn’t it? Archer said. How far are they from the precipice? No one can say, but we’ve never seen so many die. Let’s go take a sip…”