The melting Arctic shows that climate change is already upon us

Melting ice near to Greenland. Image: Getty.

Scientists have known for a long time that as climate change started to heat up the Earth, its effects would be most pronounced in the Arctic. This has many reasons, but climate feedbacks are key. As the Arctic warms, snow and ice melt, and the surface absorbs more of the sun’s energy instead of reflecting it back into space. This makes it even warmer, which causes more melting, and so on.

This expectation has become a reality that I describe in my new book “Brave New Arctic”. It’s a visually compelling story: the effects of warming are evident in shrinking ice caps and glaciers and in Alaskan roads buckling as permafrost beneath them thaws.

But for many people the Arctic seems like a faraway place, and stories of what is happening there seem irrelevant to their lives. It can also be hard to accept that the globe is warming up while you are shoveling out from the latest snowstorm.

Since I have spent more than 35 years studying snow, ice and cold places, people often are surprised when I tell them I once was skeptical that human activities were playing a role in climate change. My book traces my own career as a climate scientist and the evolving views of many scientists I have worked with. When I first started working in the Arctic, scientists understood it as a region defined by its snow and ice, with a varying but generally constant climate. In the 1990s, we realized that it was changing, but it took us years to figure out why. Now scientists are trying to understand what the Arctic’s ongoing transformation means for the rest of the planet, and whether the Arctic of old will ever be seen again.

Arctic sea ice has not only been shrinking in surface area in recent years – it’s becoming younger and thinner as well.

Evidence piles up

Evidence that the Arctic is warming rapidly extends far beyond shrinking ice caps and buckling roads. It also includes a melting Greenland ice sheet; a rapid decline in the extent of the Arctic’s floating sea ice cover in summer; warming and thawing of permafrost; shrubs taking over areas of tundra that formerly were dominated by sedges, grasses, mosses and lichens; and a rise in temperature twice as large as that for the globe as a whole. This outsized warming even has a name: Arctic amplification.

The Arctic began to stir in the early 1990s. The first signs of change were a slight warming of the ocean and an apparent decline in sea ice. By the end of the decade, it was abundantly clear that something was afoot. But to me, it looked like natural climate variability. As I saw it, shifts in wind patterns could explain a lot of the warming, as well as loss of sea ice. There didn’t seem to be much need to invoke the specter of rising greenhouse gas levels.

Collapsed block of ice-rich permafrost along Drew Point, Alaska, at the edge of the Beaufort Sea. Coastal bluffs in this region can erode 20 meters a year (around 65 feet). Image: USGS.

In 2000 I teamed up with a number of leading researchers in different fields of Arctic science to undertake a comprehensive analysis of all evidence of change that we had seen and how to interpret it. We concluded that while some changes, such as loss of sea ice, were consistent with what climate models were predicting, others were not.

To be clear, we were not asking whether the impacts of rising greenhouse gas concentrations would appear first in the Arctic, as we expected. The science supporting this projection was solid. The issue was whether those impacts had yet emerged. Eventually they did – and in a big way. Sometime around 2003, I accepted the overwhelming evidence of human-induced warming, and started warning the public about what the Arctic was telling us.


Seeing is believing

Climate change really hit home for me when when I found out that two little ice caps in the Canadian Arctic I had studied back in 1982 and 1983 as a young graduate student had essentially disappeared.

Bruce Raup, a colleague at the National Snow and Ice Data Center, has been using high-resolution satellite data to map all of the world’s glaciers and ice caps. It’s a moving target, because most of them are melting and shrinking – which contributes to sea level rise.

One day in 2016, as I walked past Bruce’s office and saw him hunched over his computer monitor, I asked if we could check out those two ice caps. When I worked on them in the early 1980s, the larger one was perhaps a mile and a half across. Over the course of two summers of field work, I had gotten to know pretty much every square inch of them.

When Bruce found the ice caps and zoomed in, we were aghast to see that they had shrunk to the size of a few football fields. They are even smaller today - just patches of ice that are sure to disappear in just a few years.

Hidden Creek Glacier, Alaska, photographed in 1916 and 2004, with noticeable ice loss. Image: S.R. Capps, USGS (top), NPS (bottom).

Today it seems increasingly likely that what is happening in the Arctic will reverberate around the globe. Arctic warming may already be influencing weather patterns in the middle latitudes. Meltdown of the Greenland ice sheet is having an increasing impact on sea level rise. As permafrost thaws, it may start to release carbon dioxide and methane to the atmosphere, further warming the climate.

The ConversationI often find myself wondering whether the remains of those two little ice caps I studied back in the early 1980s will survive another summer. Scientists are trained to be skeptics, but for those of us who study the Arctic, it is clear that a radical transformation is underway. My two ice caps are just a small part of that story. Indeed, the question is no longer whether the Arctic is warming, but how drastically it will change – and what those changes mean for the planet.

Mark Serreze, Research Professor of Geography and director, National Snow and Ice Data Center, University of Colorado.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

To beat rising temperatures, Vienna launches a network of 'Cool Streets'

A Vienna resident cools off at one of the city's new Cool Streets installations. (Courtesy Christian Fürthner/Mobilitätsagentur Wien)

Over the past several months, Austria has recorded its highest unemployment rate since World War II, thanks to the economic aftermath of the Covid-19 pandemic. With no job or a suddenly smaller income – not to mention the continued threat of the virus – many Viennese will opt for a staycation this summer.  

At the same time, last year, Austria’s capital experienced 39 days with temperatures of over 30°C (86°F), one of its hottest summers in history according to the Central Institute for Meteorology and Geodynamics.

Climate experts expect a similarly sizzling 2020 season, and city officials are now doubling down on efforts to combat the heat by launching a “Cool Streets” initiative as well as a new, state-of-the-art cooling park.

“As the city councilwoman in charge of climate, it is my job to ensure local cooling,” Vienna’s deputy mayor Birgit Hebein proclaimed at the opening of one of 22 new “Cool Streets” on 22 June.

“In Austria, there are already more heat deaths than traffic fatalities,” she added.

Hebein was referring to the 766 people the Austrian Agency for Health and Food Security included in its 2018 heat-associated mortality statistics. The number was up by 31% compared to 2017, and in contrast to the 409 people who died in traffic collisions the same year.

The project includes 18 temporary Cool Streets located across the city, plus four roads that will be redesigned permanently and designated as “Cool Streets Plus”.

“The Plus version includes the planting of trees. Brighter surfaces, which reflect less heat, replace asphalt in addition to the installation of shadow or water elements,” said Kathrin Ivancsits, spokeswoman for the city-owned bureau Mobilitätsagentur, which is coordinating the project.


Vienna's seasonal Cool Streets provide shady places to rest and are closed to cars. (Petra Loho for CityMetric)

In addition to mobile shade dispensers and seating possibilities amid more greenery provided by potted plants, each street features a steel column offering drinking water and spray cooling. The temporary Cool Streets will also remain car-free until 20 September.

A sensor in the granite base releases drinking water and pushes it through 34 nozzles whenever the outside temperature reaches 25°C (77°F) . As soon as the ambient temperature drops to 23°C (73°F), the sensor, which operates from 10 a.m. to 8 p.m., turns off the water supply.

The sensors were included in part to allay concerns about legionella, a pathogenic bacteria that can reproduce in water.  

“When the spray stops, the system drains, and therefore no microbial contamination can develop,” said Dr. Hans-Peter Hutter, deputy head of the Department of Environmental Health at the Center for Public Health at Medical University Vienna, in a televised interview.

Hutter also assured the public that there is no increased risk of a Covid-19 infection from the spray as long as people adhere to the one-meter social distance requirement.


But Samer Bagaeen of the University of Kent's School of Architecture and Planning notes that air cooling systems, like the ones used in Germany at abattoirs, have been found recently to be a risk factor for Covid-19 outbreaks.

“The same could be said for spay devices,” he warned.

Vienna’s district councils selected the 22 Cool Street locations with the help of the city’s Urban Heat Vulnerability Index. The map shows where most people suffer from heat by evaluating temperature data, green and water-related infrastructure, and demographic data.

“Urban heat islands can occur when cities replace the natural land cover with dense concentrations of pavement, buildings, and other surfaces that absorb and retain heat,” as the US Environmental Protection Agency states.


A rendering of Vienna's planned park featuring a Coolspot, which is scheduled to open in August. Click to expand.
(Courtesy Carla Lo Landscape Architecture)

Vienna’s sixth district, Mariahilf, is such an area. The construction of the capital’s first “Cooling Park”, a €1 million project covering the 10,600 square-metre Esterházypark, is designed to provide relief. 

Green4Cities, a centre of excellence for green infrastructure in urban areas, designed the park’s main attraction, the “Coolspot”. The nearly 3.40-metre high steel trellis holds three rings equipped with spray nozzles. Textile shading slats, tensioned with steel cables, cover them.

The effects of evaporation and evapotranspiration create a cooler microclimate around the 30 square-metre seating area, alongside other spray spots selectively scattered across the park.

The high-pressure spray also deposits tiny droplets on plant and tree leaves, which stimulates them to sweat even more. All together, these collective measures help to cool their surroundings by up to six degrees.

The landscape architect Carla Lo and her team planned what she calls the “low-tech” park components. “Plants are an essential design element of the Cooling Park,” Lo says. “By unsealing the [soil], we can add new grass, herbaceous beds, and more climate-resistant trees to the existing cultivation”.

Light-coloured, natural stone punctuated by grass seams replaces the old concrete surfaces, and wooden benches meander throughout the park.

Living near the park and yearning for an urban escape close by, Lo says she’s motivated to ensure the park is completed by mid-August.

“If we don't do anything, Vienna will be another eight degrees Celsius hotter in 2050 than it already is,” Hebein said.

Vienna recently came in first in the World's 10 Greenest Cities Index by the consulting agency Resonance.

“There is no one size fits all on how cities respond to urban heat,” says the University of Kent’s Bagaeen, who points out that Vienna was one of the first European cities to set up an Urban Heat Islands Strategic Plan in 2015.

In the short term, prognoses on the city’s future development may be more difficult: Vienna votes this autumn.

Petra Loho is a journalist and photographer based in Austria.