Friday, July 29, 2022

Melting glaciers show us how much climate change is impacting the environment, Dr Heïdi Sevestre says
Heïdi was a teenager when she decided that she wanted to pursue a career as a glaciologist.(Supplied)

Being a glaciologist is like being an astronaut in a frozen world, Dr Heïdi Sevestre says.

The 34-year-old has been studying glaciers for about 10 years. In 2022, she was named the inaugural recipient of the Shackleton Medal for Protection of the Polar Regions for her work as a researcher, climate activist and expedition leader.

"There's something hypnotising, something absolutely mesmerising, about the icy environments," Dr Sevestre tells ABC RN's Late Night Live.

"This is probably one of the reasons why, as [a] scientist, [I] feel so strongly about protecting these environments."
'In love with these glaciers'

Dr Sevestre's unwavering passion for nature began when she was growing up in the French Alps.

"I started hiking, climbing, mountaineering, and eventually I discovered the high-altitude environments and I simply fell in love with these glaciers," she says.

Dr Sevestre devotes her time to scientific research and science outreach.
(Supplied: Silje Smith Johnsen)

At the age of 17, a mountain guide suggested she might be interested in pursuing a career in glaciology. Since then, she studied physical geography, geology, and glaciology, and has been on numerous expeditions in the polar regions.

Sometimes she has carried out these expeditions in the harshest conditions, trekking in 140 kilometres per hour winds and in temperatures dipping below minus 15 degrees Celsius.

"Last year, I got the chance to do probably one of the most challenging expeditions of my life with some of my brightest and brilliant female colleagues," she says.

In 2021, a small team called the Climate Sentinels took part in a month-long expedition to gain a better understanding of the drivers of Arctic change.

It meant travelling 450 kilometres on skis across the Norwegian archipelago of Svalbard, in the Arctic Ocean, to collect ice and snow samples.
Collecting ice and snow samples in the Arctic.(Supplied)

The small archipelago of Svalbard sits between Northern Norway and the North Pole.

It holds a very dear place in Dr Sevestre's heart.

"[The archipelago is] covered 60 per cent by glaciers, so it's truly paradise for a glaciologist like me. But it's also a place where you feel the true power of nature," she says.

Indeed, the team faced such bad weather on their 2021 expedition that they had to bury themselves in snow to protect themselves and avoid losing their tents.

"We got to experience some of the most terrifying conditions I've ever seen on the archipelago. And bear in mind that I've been travelling to Svalbard since 2008," she says.

"We got hit by a series of scary and dramatic storms, which are the expression of climate change."

Svalbard is also home to about 3,000 polar bears and on that trip, the team had to escape one.

But while this work has its perils, it's a risk Dr Sevestre is willing to take to raise awareness of the impact climate change is having on glaciers and the implications this has on rising sea levels.

"What's super important about the surging glaciers is that they are game changers when it comes to predicting future sea level rise. This is a big part of our work right now," she says.
'Surging glaciers are so erratic'

Dr Sevestre belongs to an organisation called Glaciers on the Move, which tracks the speed of surging glaciers.

She says results can sometimes be surprising.

"When you look at glaciers around the world, you might think that they are pretty static, that these glaciers don't do much apart from melting," she says.

However, the results for Svalbard have shown that these types of glaciers can change their behaviour.

Ahead of the expedition, Dr Sevestre and her team prepared themselves for avalanches.(Supplied)

"For most of their lives they are lazy, they don't do very much, they move extremely slowly," she says.

"And suddenly, for reasons that we still struggle to understand, they can move extremely rapidly."

According to Dr Sevestre, the organisation has recorded glaciers moving over as much as 10 to 50 meters per day, over several years.

"These surging glaciers are so erratic, so chaotic, that they can suddenly, over the space of a few months, bring huge amounts of ice into the oceans and completely change our projections of future sea level," she says.

"A moving glacier is pretty much like a bulldozer that is unstoppable. It will destroy anything that is in its way."

She points to a recent disaster in Pakistan where an ice-dammed lake burst into a valley and destroyed houses and agricultural land.

Fortunately, no lives were lost as the incident was pre-empted when the glacier started to surge back in 2018.

Fine particles of black carbon

The Climate Sentinels spent 32 days in freezing temperatures collecting snow samples for their expedition. (Supplied)

In Svalbard, she's working on the frontline of climate change: a recent study has claimed that the North Barents Sea region in the Arctic is warming five to seven times faster than the rest of the world.

She says that they now know that these ice masses are being greatly affected by the increasing global temperatures linked to the burning of fossil fuels.

Dogs often accompany Dr Sevestre and the other scientists on their expeditions. (Supplied: Nina Adjanin )

There's another significant effect too.

"Every time we burn fossil fuels — whether it's wood, coal, gas, natural gas or oil — we emit fine particles and among those fine particles, you get this black carbon," she says.

These fine particles of black carbon can travel thousands of kilometres.

"For example, every time there are wildfires in California, the soot [or] the black carbon can travel as far as Greenland," she says.

"Today, we see that the Arctic is melting faster, not only because global temperatures are increasing, but also because we have more and more air pollution, more and more of this black carbon being deposited on snow and ice."

Glaciers are important water resources, she says. 
As temperatures rise, they are melting which affects sea levels.
(Supplied: Frederic de La Mure)

She says about 40 per cent of the melting of the Arctic today can be attributed to deposits of black carbon.

There's still time to stop it from getting worse, she adds, but only if we start taking action immediately.

"I have to stay optimistic. This is my duty," she says.

"If us the scientists, if the people who are so passionate about the polar regions give up, why should people care about those regions? Why should people act?"

"But it's truly now or never."


No comments: