AFP

US President Joe Biden flew over the devastation left by Hurricane Ian in Florida on a politically charged trip Wednesday that marked a truce with bitter Republican critic and potential 2024 opponent, Governor Ron DeSantis.

The Democrat, accompanied by First Lady Jill Biden, boarded a helicopter at Fort Myers for an aerial inspection of the havoc wreaked in one of the worst storms ever to hit the country.

“Everything — this historic and titanic, unimaginable storm ripped it to pieces,” Biden said in a speech after witnessing the destruction. “You’ve got to start from scratch.”

Authorities say at least 93 people — more than 100 according to US television networks citing local officials — died in Hurricane Ian.

The Category 4 storm flattened whole neighborhoods on the Sunshine State’s west coast, knocking out power for millions of people, and then weakened before tearing into South Carolina and up the East Coast.

For Biden, who visited hurricane-hit Puerto Rico on Monday, the Florida trip also had an inescapable political dimension, taking him into the stronghold of both DeSantis and Biden’s scandal-plagued predecessor in the White House, Donald Trump.

The Democrat, who says he wants to seek a second term despite already being the oldest man ever in the job at 79, could realistically end up facing a rematch with Trump in two years or a challenge from the up-and-coming DeSantis.

DeSantis has been a caustic critic, as he builds his brand of muscular right-wing politics in a bid to replace Trump as the biggest name in the Republican party. Biden has returned fire, painting DeSantis as part of what he says is an increasingly extreme right.

The hurricane, however, has prompted a ceasefire, with phone calls between the two men and acknowledgement from DeSantis that the federal government was quick to provide assistance.

“Mr President, welcome to Florida. We appreciate working together,” DeSantis said at the damaged waterfront neighborhood of Fisherman’s Pass.

Biden returned the warm words, saying DeSantis had “done a good job.”

“We have very different political philosophies, but we’ve worked hand in glove.”

– ‘Above politics’ — for now –

Biden’s main goal, White House Press Secretary Karine Jean-Pierre said, is to check that “the people of Florida have what they need.”

In addition to getting briefings from federal emergency management chief Deanne Criswell and DeSantis, Biden met small business owners and local storm survivors.

In his remarks, he emphasized togetherness — something rarely celebrated in today’s gladiatorial Democrat vs Republican politics.

“This is the United States,” he said in his remarks, stressing the word “united.”

Biden’s visit to Puerto Rico earlier in the week covered similar ground, although there he was updated on recovery from Hurricane Fiona, which hit the island last month.

Again, Biden stressed the unity message, telling the Caribbean territory — which often feels overlooked by the mainland and the federal government — that “all of America’s with you.”

The disagreements with DeSantis, however, are many and will likely resurface as soon as Floridians recommence a semblance of their previous lives.

DeSantis opposed Biden on his Covid-19 policies during the pandemic, accusing the president of overreach. He has likewise made himself the standard bearer of the conservative backlash to growing tolerance for LGBT issues — something Biden has championed.

Another right-wing Florida Republican who often comes under fire from Biden, Senator Rick Scott, was also present for the visit. But again, Biden held his tongue.

The visit was “above politics,” Jean-Pierre said.

“There will be plenty of times, plenty of time to discuss differences between the president and the governor. Now is not the time.”

“All kinds of crazy things” is how Carolyn Bertozzi, a 2022 Nobel laureate, describes her life’s work. Actually performing “chemistry in cells and in people.”

When she started her research in 1997, the Stanford professor was aiming only to observe the evolution of certain molecules on the surface of cancer cells. 

Today, thanks to her discoveries, at least two companies — including one she co-founded — are developing innovative cancer treatments.

The multitude of applications made possible by her findings are impressive: delivering treatments with extreme precision, understanding better how drugs act inside the body, visualizing certain bacteria, to name a few.

“I can’t even really enumerate them. The vast majority of those applications I would never have foreseen,” she told AFP in an interview.

The Nobel Prize committee recognized Bertozzi’s pioneering advances on Wednesday, making her only the eighth woman to win the chemistry prize, at just 55 years old.

– Lego pieces –

Her journey began when she found she had a passion for organic chemistry, while taking pre-medicine courses at Harvard. 

The subject is notoriously — many say fiendishly — difficult, but she credits an “amazing professor,” the late David Evans, for bringing it to life — and changing the course of her life.

“I said, forget the med school thing. I’m going to be a chemist,” said Bertozzi, whose sister is a professor of applied mathematics, and father a retired professor of physics.

After completing her post-doctorate and joining the faculty at UC Berkeley, she wanted to take a closer look at glycans: complex carbohydrates, or sugars, located on the surface of cells, which “go through structural changes” when they become cancerous.

At the time, “there was no tool to image sugars, like in a microscope, for example,” she said.

She had an idea that would require two chemical substances that fit together perfectly, like pieces of lego.

The first lego is fed to cells via a sugar. The cell metabolizes it and places it on the tip of the glycan. The second piece of lego, a fluorescent molecule, is injected into the body.

The two lego pieces click together, and voila: hidden glycans reveal themselves under a microscope.

This technique is inspired by “click chemistry” developed independently by Denmark’s Morten Meldal and American Barry Sharpless — Bertozzi’s co-winners. But their discoveries relied on using copper as a catalyst, which is toxic to the body. 

One of Bertozzi’s great leaps was achieving the same type of ultra-efficient reaction without copper.

The other tour de force: making it all happen without wreaking havoc with other processes in the body.

“The beauty of it is that you can take the two Legos and click them together, even if they’re surrounded by millions of other very similar plastic toys,” she explained.

She coined the term “bioorthogonal chemistry,” meaning a reaction that doesn’t interfere with other biochemical processes. Perfecting the technique took 10 years.

– ‘Cycle of science’ –

Researchers are now leveraging these breakthroughs to develop cancer treatments. 

Glycans on cancer cells “are able to hide the cancer cell from the immune system — and so your body can’t fight it, it can’t see it,” she explains.

Using bioorthogonal chemistry, “we made a new type of medicine, which basically acts like a lawnmower,” says Bertozzi.

The first lego attaches to the cancer cell’s surface, and the second, which clips onto it, is equipped with an enzyme that “mows off the sugars as if they’re just grass, it cuts the grass and the sugars fall off,” she says with a smile.

The drug is currently being tested in the early stages of a clinical trial.

Another company is seeking to use bioorthogonal chemistry to better target cancer treatment. The first lego piece is injected into a tumor, then a second, which carries the drug, attaches itself and acts only on its target.

“So that allows the oncologist to treat the tumor and kill the tumor without exposing the person’s entire body to a toxic chemical,” she says.

“What the future holds is hopefully an impact in human health,” says Bertozzi. “But the people who decide that more so than myself, are the students and postdocs that join my lab.”

Hundreds of them, current and former, filled her email box with messages of congratulations this morning.

“That really is the cycle of science —  it’s being mentored and then mentoring” she adds. And “mentoring students gives you an opportunity to amplify the impact of your science.”

The Nobel Chemistry Prize was awarded to three scientists on Wednesday for their work on click chemistry, a way to snap molecules together like Lego that experts say will soon “change the world”.

But how exactly does it work?

Imagine two people walking through a mostly empty room towards each other then shaking hands. 

“That’s how a classical chemical reaction is done,” said Benjamin Schumann, a chemist at Imperial College London.

But what if there was lots of furniture and other people clogging up the room?

“They might not meet each other,” Schumann said.

Now imagine those people were molecules, tiny groups of atoms that form the basis of chemistry.

“Click chemistry makes it possible for two molecules that are in an environment where you have lots of other things around” to meet and join with each other, he told AFP.

The way click chemistry snaps together molecular building blocks is also often compared to Lego.

But Carolyn Bertozzi, who shared this year’s chemistry Nobel with Barry Sharpless and Morten Meldal, said it would take a very special kind of Lego.

Even if two Legos were “surrounded by millions of other very similar plastic toys” they would only click in to each other, she told AFP.

– ‘Changed the playing field’ – 

Around the year 2000, Sharpless and Meldal separately discovered a specific chemical reaction using copper ions as a catalyst which “changed the playing field” and became “the cream of the crop”, said Silvia Diez-Gonzalez, a chemist at Imperial College London.

Copper has many advantages, including that reactions could involve water and be done at room temperature rather than at high heat which can complicate matters.

This particular way of connecting molecules was far more flexible, efficient and targeted than had ever been possible before.

Since its discovery, chemists have been finding out all the different kinds of molecular architecture they can build with their special new Lego blocks.

“The applications are almost endless,” said Tom Brown, a British chemist at Oxford University that has worked on DNA click chemistry.

But there was one problem with using copper as a catalyst. It can be toxic for the cells of living organisms — such as humans.

So Bertozzi built on the foundations of Sharpless and Meldal’s work, designing a copperless “way of using click chemistry with biological systems without killing them”, Diez-Gonzalez said.

Previously the molecules clicked together in a straight flat line — like a seat belt — but Bertozzi discovered that forcing them “to be a bit bent” made the reaction more stable, Diez-Gonzalez said.

Bertozzi called the field she created bioorthogonal chemistry — orthogonal means intersecting at right angles.

– ‘Tip of the iceberg’ –

Diez-Gonzalez said she was “a bit surprised” that the field had been awarded with a Nobel so soon, because “there are not that many commercial applications out there yet”.

But the future looks bright.

“We’re kind of at the tip of the iceberg,” said American Chemical Society President Angela Wilson, adding that this “chemistry is going to change the world.”

Bertozzi said that there are so many potential uses for click chemistry, that “I can’t even really enumerate them”.

One use is for developing new targeted medicines, some of which could involve “doing chemistry inside human patients to make sure that drugs go to the right place,” she told the Nobel conference. 

Her lab has started research on potential treatments for severe Covid, she added.

Another hope is that it can lead to a more targeted way to diagnose and treat cancer, as well make chemotherapy have fewer, less severe side effects.

It has even created a way to make the bacteria that causes Legionnaires’ disease become fluorescent so it is easier to spot in water supplies. 

Already, click chemistry has been used “to create some very, very durable polymers” that protect against heat, as well as in forms of glue in nano-chemistry, Meldal told AFP.

Wilson said other future applications include personalised medicines, antibacterial and antiviral drugs, brightening agents and more.

“I think it’s going to completely revolutionise everything from medicine to materials,” she said.

Human-caused climate change made this summer’s drought across the Northern Hemisphere at least 20 times more likely, according to a rapid analysis released Wednesday that warns such extreme dry periods will become increasingly common with global heating. 

The three months from June-August were the hottest in Europe since records began, and the exceptionally high temperatures led to the worst drought the continent has witnessed since the Middle Ages. 

Crops withered in European breadbaskets, as the historic dry spell drove record wildfire intensity and placed severe pressure on the continent’s power grid. 

Successive heatwaves between June and July, which saw temperatures top 40 degrees Celsius (104 degrees Fahrenheit) in Britain for the first time, saw some 24,000 excess deaths in Europe.

China and North America also experienced unusually high temperatures and exceptionally low rainfall over the period.

An international team of climate scientists have determined the warming caused by human activity made such extreme weather significantly more likely than it would have been at the dawn of the industrial age. 

The World Weather Attribution service calculated that the agricultural and ecological drought over the Northern Hemisphere was at least 20 times likelier thanks to global heating. 

“The 2022 summer has shown how human-induced climate change is increasing the risks of agricultural and ecological droughts in densely populated and cultivated regions of the North Hemisphere,” said Sonia Seneviratne, a professor at the Institute for Atmospheric and Climate Science at ETH Zurich in Switzerland and one of the study contributors.

– ‘Faster than expected’ –

To quantify the effect of human-caused climate change on soil moisture levels, the team analysed weather data and computer simulations to compare the real climate as it is today — that is, some 1.2C hotter than pre-industrial levels — with a climate absent of any human-induced heating.

They found that western and central Europe experienced particularly severe drought and substantially reduced crop yields.

Moisture in the top 7cm of soil across the Northern Hemisphere was made five times likelier to experience severe drought due to climate change, the study found. 

For the top one metre of soil — known as the root zone — this summer’s dryness was made at least 20 times likelier due to global heating.

“Really what is most relevant for agriculture and ecological impacts is the top one metre of the soil because that’s where plants have their roots,” said Seneviratne.

Overall, a Northern Hemisphere drought such as this summer’s was now likely to occur once every 20 years in today’s climate, compared to once every 400 years in the mid eighteenth century.

Producers in Europe and China have warned of significantly lower than expected harvests in crop staples due to the dry spell, after food prices spiked to multi-year highs following Russia’s invasion of Ukraine in February.

Friederike Otto, senior lecturer in climate science at the Imperial College London, called the crop shortfall “particularly worrying”.

“It followed a climate change-fuelled heatwave in South Asia that also destroyed crops, and happened at a time when global food prices were already extremely high due to the war in Ukraine,” she said.

Otto said the Northern Hemisphere in general was showing a “pure climate change signal” in its overall warming trends. 

Maarten van Aalst, director of the Red Cross Red Crescent Climate Centre and professor of climate and disaster resilience at University of Twente, said governments needed to do far more to prepare for future heat and drought shocks, which will become ever more frequent as temperatures rise. 

“We’re talking tens of thousands of people killed by these phenomena and one thing that we’re seeing is the impacts compounding and cascading across regions and sectors,” he said. 

“It’s playing out in front of our eyes even faster than we might have expected.”