Climate change attacked crucial Arctic sea ice thickness in two sudden big gobbles instead of steady nibbling, a new study says.
A little more than 15 years ago, sea ice quickly lost more than half its thickness, becoming weaker, more prone to melting and less likely to recover, according to the study that emphasizes the importance of two big "regime shifts" that changed the complexion of the Arctic.
Those big bites came in 2005 and 2007. Before then, Arctic sea ice was older and misshapen in a way that made it difficult to move out of the region. That helped the polar area act as the globe's air conditioner even in warmer summers. But now the ice is thinner, younger and easier to push out of the Arctic, putting that crucial cooling system at more risk, the study's lead author said.
The midnight sun shines across sea ice July 23, 2017, along the Northwest Passage in the Canadian Arctic. A new study says the thickness of sea ice dropped sharply in two sudden events about 15 years ago.
Before 2007, 19% of the sea ice in the Arctic was at least 13 feet thick (4 meters) — taller than most elephants — but now only about 9.3% of ice is at least that thick. And the age of the ice has dropped by more than a third, from an average of 4.3 years to 2.7 years, according to the study in Wednesday's journal Nature.
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It cited "the long-lasting impact of climate change on the Arctic sea ice."
"Ice is much more vulnerable than before because it's thinner, it can easily melt," said study lead author Hiroshi Sumata, a sea ice scientist at the Norwegian Polar Institute. Thicker sea ice is crucial to all sorts of life in the Arctic, he said.
The study shows "how the Arctic sea ice environment has undergone a fundamental shift," said Walt Meier, a scientist at the National Snow and Ice Data Center, who wasn't part of the research. "This paper helps explain why the sea ice has not recovered from those big drops."
Past studies concentrated more on the extent of Arctic sea ice, or how widespread it is, because that's easily measured by satellites, which don't observe volume well. But 90% of the sea ice eventually is pushed out of the Arctic through the Fram Strait by Greenland, so Sumata overcame the challenges of measuring from space by focusing his observations on that ground-based choke point.
He found that first ice was getting younger, which made it thinner and more uniform, and easier to push out through the Fram Strait. Thicker ice has all sorts of edges and weird shapes that make it harder to force out of the Arctic because of aerodynamics, but that's not the case for sleeker, younger ice, Sumata said.
Scientists had known before that sea ice was shrinking in extent and getting thinner, but this "flushing" is key, said Mark Serreze, director of the National Snow and Ice Data Center, who wasn't part of the study.
"Such flushing episodes have reduced the residence time of ice in the Arctic Ocean by more than a year so there's less time for it to thicken and it's the thick ice that's resistant to melting out," Serreze said in an email. "But since the Arctic is quickly warming up, we're probably past the point of hoping the Arctic Ocean can recover."
What likely happened in 2005 and 2007 were periods with warm, large, ice-free open water in the Arctic that exceeded periods of previous summers, Sumata said. White ice reflects the sun's rays, but the dark ocean absorbs it and warms up — something called ice albedo feedback. This cycle of warmer water made it harder for ice to form, survive and get thicker, he said.
Once the ocean has accumulated that heat, it can't go back easily. So in the future more big warmer shifts can happen to make ice thinner and weaker, but don't count on sudden, healing cooling changes, scientists said.
Sumata and Serreze think those sudden warm jumps will happen soon and are surprised they haven't quite happened yet. Recent projections predict the Arctic ocean will be ice free in parts of summer in 20 to 30 years.
Sea ice thickness and overall Arctic health is crucial even to areas thousands of miles away that don't freeze up, Sumata said.
"It will affect the entire Earth because the north and south pole is something like a radiator of the Earth, the air conditioning system of the Earth," Sumata said. "And the situation we observed indicates the air conditioner is not working well."
8 things to do right now in your community to prepare for climate change
8 things to do right now in your community to prepare for climate change
Climate anxiety and climate-related trauma are mental health concerns rooted in real experiences, such as natural disasters, and existential worry for the future.
Roughly half of young people—those who will inherit the consequences of climate change complacency and live through the most severe effects of extreme weather—report that climate change negatively affects their daily lives, according to a global survey of 10,000 people between the ages of 16 and 25. The majority of respondents said that in the context of climate change, they are frightened of the years ahead.
This concern is prevalent in the United States as well, with more than half of Americans stating climate change is the single most important issue facing society today. Large swaths of the U.S. are facing climate-related flood risks due to rising sea and freshwater levels and increased rainfall. Roughly 80% of the country is experiencing unusually dry conditions, most notably the Western U.S., which has been gripped by a megadrought. Cities are getting hotter, while wildfires are growing in frequency and intensity. At present, virtually every bit of the U.S. is impacted by climate change.
And yet, most people have done little, or nothing at all, to change their behavior to mitigate their own impact on the environment. When facing a problem so extensive, it can be overwhelming even to attempt to find a manageable solution. But starting small—and starting at all, really—is one of the most important things you can do.
Westfield compiled a list of eight ways people can prepare their communities for the impacts of climate change. Building climate resilience, or the ability to prepare for and respond to climate-related events, may also help ease climate anxiety, improving both the environment and one's quality of life.
Plant a rain garden or install a rain barrel
Rain gardens can help prevent erosion, absorb standing water, redirect and filter polluted runoff, and recharge groundwater supplies. A single rain garden can treat 25,000 gallons of water each year. In regions of the county like the Northeast, where climate change is predicted to lead to more heavy downpours and flooding, rain gardens can mitigate those issues. In severely drought-prone areas, a rain garden won't be effective, but a rain barrel can help collect water.
Remove invasive plant species from parks
Invasive species often thrive under the extreme conditions of climate change. Plants grow larger and faster when higher carbon dioxide levels—a key consequence of climate change—are present. Research suggests invasive species are more effective at utilizing higher CO2 concentrations. As they grow larger and more prolific, they outcompete native species for space, water, light, and nutrient resources. Removing invasive species cancels this competition and allows native species to thrive.
Replace grass lawns with eco-alternatives
According to the Environmental Protection Agency, Americans use a combined 8 billion gallons of water every day for lawn and garden irrigation, some of which is lost to evaporation and runoff. The majority of household water usage is diverted to outdoor purposes. This is a hugely wasteful use of scarce water resources in severely drought-ridden areas like the American West, and as a result, nonfunctional turf grass is banned in many places. Climate-friendly alternatives include no-mow lawns, turf lawns allowed to grow wild, lawns comprised of drought-tolerant native plants that thrive under local conditions, usually requiring less water, or xeriscaping.
Use renewable energy options
Some households have the option to choose the source and supplier of their electricity. Where wind or solar is available and compatible, customers may opt for these cleaner sources compared to fossil-fuel-generated electricity. Alternatively, getting set up with solar panels and other renewable energy sources will provide greater energy independence in the face of power outages from natural disasters.
Use natural methods to repel mosquitoes
Climate change has already prolonged mosquito season by more than a month, with more mosquito days expected in the future. Mosquitoes thrive in temperatures between 50-95 degrees Fahrenheit and relative humidity of 42% or higher. An analysis of 239 sites across the U.S. revealed these conditions are becoming more common due to climate change. These changes bring an increased risk for the spread of mosquito-borne illnesses like West Nile virus. Some natural ways to repel mosquitoes as mosquito days increase include essential oils, witch hazel, and citronella.
Plant trees
Trees are stalwart defenders against climate change, particularly in urban heat islands, which often lose trees to housing and infrastructure development. Trees can mitigate the impacts of extreme heat by releasing water vapor and cooling the air around them, as well as shading the ground beneath them. Their absorbent roots reduce flooding and prevent soil erosion. Residents can seek out community planting or beautification organizations that plant and maintain trees in public spaces.
Support local farmers
Farmers are facing less reliable growing seasons due to climate change. Some have been forced to fallow fields because there isn't enough water to sustain their crops. In other parts of the country, too much rain is drowning young plants. Invasive species which thrive under extreme conditions are decimating the crops that do succeed. Supporting local farmers contending with these variables will not only keep the cost to consumers down but will also ensure growers stay in business. Community-supported agriculture groups exist across the country, and many communities and local co-ops sponsor regular farmers markets, where local farmers have direct access to the buying public.
Get elected to HOA or neighborhood association
Getting involved at a hyper-local level through a homeowner or neighborhood association can position you to effect small but impactful immediate changes, initiate climate-centric conversations, and find a group of people working towards the same goal. HOAs often provide access to volunteering opportunities, as well as standardized maintenance protocols, which can mitigate the overuse of water and other resources.
This story originally appeared on Westfield and was produced and distributed in partnership with Stacker Studio.
