Ask the Weather Guys: How is the Artic sea ice situation?
STEVEN A. ACKERMAN and JONATHAN MARTIN | UW-Madison department of atmospheric and oceanic sciences
Q: How is the Artic sea ice situation?
A: The sea ice cover in the Arctic Ocean is one of the key components of our climate system.
The brightness of the sea ice reflects more solar energy to space than open water. Global warming is amplified in the Arctic as the ice cover decreases. This is referred to as the ice-albedo feedback.
As the polar regions warm, the amount of sea ice decreases, which allows more solar energy to be absorbed by the Arctic Ocean, which increases the warming, leading to more loss of sea ice. In the winter, the sun is below the Arctic Circle, and so the sea ice can grow back.
DAVID GOLDMAN, ASSOCIATED PRESS
Arctic sea ice coverage has been declining since satellite-based observations started in 1978.
Observing sea ice coverage from satellites started in 1978. Those satellite-based observations have measured rapid changes in ice coverage, and that coverage has been declining. The overall, downward trend in the minimum extent from 1979 to 2021 is 13% per decade relative to the 1981 to 2010 average. The loss of sea ice is about 31,100 square miles per year, equivalent to losing the size of the state of South Carolina.
The Arctic sea ice coverage typically reaches its smallest amount in mid-September. This is in response to the setting sun and falling temperatures. Then, the ice extent begins to increase and does throughout the winter. This year, based on satellite observations, the minimum occurred on Sept. 16 of 1.82 million square miles. The 2021 minimum is the 12th lowest in the satellite record. The last 15 years are the lowest 15 sea ice extents in the satellite record.
Multiyear ice is sea ice that exists for more than one year. Multiyear ice extent is one of the lowest on record.
In August the U.N.-appointed Intergovernmental Panel on Climate Change published a report summarizing the latest authoritative scientific information about global warming. Here are five important takeaways:
Pope, patriarch and Canterbury abbot issue climate appeal in first-ever joint statement
AP FILE
The report says almost all of the warming that has occurred since pre-industrial times was caused by the release of heat-trapping gases such as carbon dioxide and methane. Much of that is the result of humans burning fossil fuels — coal, oil, wood and natural gas.
Scientists say that only a fraction of the temperature rise recorded since the 19th century can have come from natural forces.
AP FILE
The report says almost all of the warming that has occurred since pre-industrial times was caused by the release of heat-trapping gases such as carbon dioxide and methane. Much of that is the result of humans burning fossil fuels — coal, oil, wood and natural gas.
Scientists say that only a fraction of the temperature rise recorded since the 19th century can have come from natural forces.
Pope, patriarch and Canterbury abbot issue climate appeal in first-ever joint statement
AP Photo/Fernando Vergara, File
Almost all countries have signed up to the 2015 Paris climate accord that aims to limit global warming to 2 degrees Celsius (3.6 Fahrenheit) — and ideally no more than 1.5 degrees Celsius (2.7 degrees Fahrenheit) — by the year 2100, compared to the late 19th century.
The report's 200-plus authors looked at five scenarios and concluded that all will see the world cross the 1.5-degree threshold in the 2030s — sooner than in previous predictions. Three of those scenarios will also see temperatures rise 2 degrees Celsius above the pre-industrial average.
About the photo: In this Wednesday, Feb. 17, 2021 file photo, a floating dock sits on the lakebed of the Suesca lagoon, in Suesca, Colombia. The lagoon, a popular tourist destination near Bogota that has no tributaries and depends on rain runoff, has radically decreased its water surface due to years of severe droughts in the area and the deforestation and erosion of its surroundings.
AP Photo/Fernando Vergara, File
Almost all countries have signed up to the 2015 Paris climate accord that aims to limit global warming to 2 degrees Celsius (3.6 Fahrenheit) — and ideally no more than 1.5 degrees Celsius (2.7 degrees Fahrenheit) — by the year 2100, compared to the late 19th century.
The report's 200-plus authors looked at five scenarios and concluded that all will see the world cross the 1.5-degree threshold in the 2030s — sooner than in previous predictions. Three of those scenarios will also see temperatures rise 2 degrees Celsius above the pre-industrial average.
About the photo: In this Wednesday, Feb. 17, 2021 file photo, a floating dock sits on the lakebed of the Suesca lagoon, in Suesca, Colombia. The lagoon, a popular tourist destination near Bogota that has no tributaries and depends on rain runoff, has radically decreased its water surface due to years of severe droughts in the area and the deforestation and erosion of its surroundings.
Pope, patriarch and Canterbury abbot issue climate appeal in first-ever joint statement
AP Photo/Victor Caivano, File
The 3,000-plus-page report concludes that ice melt and sea level rise are already accelerating. Wild weather events — from storms to heat waves — are also expected to worsen and become more frequent.
Further warming is "locked in" due to the greenhouse gases humans have already released into the atmosphere. That means even if emissions are drastically cut, some changes will be "irreversible" for centuries, the report said.
About the photo: In this Thursday, July 29, 2021 file photo, birds fly over a man taking photos of the exposed riverbed of the Old Parana River, a tributary of the Parana River during a drought in Rosario, Argentina. Parana River Basin and its related aquifers provide potable water to close to 40 million people in South America, and according to environmentalists the falling water levels of the river are due to climate change, diminishing rainfall, deforestation and the advance of agriculture.
AP Photo/Victor Caivano, File
The 3,000-plus-page report concludes that ice melt and sea level rise are already accelerating. Wild weather events — from storms to heat waves — are also expected to worsen and become more frequent.
Further warming is "locked in" due to the greenhouse gases humans have already released into the atmosphere. That means even if emissions are drastically cut, some changes will be "irreversible" for centuries, the report said.
About the photo: In this Thursday, July 29, 2021 file photo, birds fly over a man taking photos of the exposed riverbed of the Old Parana River, a tributary of the Parana River during a drought in Rosario, Argentina. Parana River Basin and its related aquifers provide potable water to close to 40 million people in South America, and according to environmentalists the falling water levels of the river are due to climate change, diminishing rainfall, deforestation and the advance of agriculture.
Pope, patriarch and Canterbury abbot issue climate appeal in first-ever joint statement
AP Photo/Julie Jacobson
While many of the report's predictions paint a grim picture of humans' impact on the planet and the consequences that will have going forward, the IPCC also found that so-called tipping points, like catastrophic ice sheet collapses and the abrupt slowdown of ocean currents, are "low likelihood," though they cannot be ruled out.
About this photo: In this Tuesday, July 20, 2021 file photok the Staten Island Ferry departs from the Manhattan terminal through a haze of smoke with the Statue of Liberty barely visible in New York. Wildfires in the American West, including one burning in Oregon that's currently the largest in the U.S., are creating hazy skies as far away as New York as the massive infernos spew smoke and ash into the air in columns up to six miles high.
AP Photo/Julie Jacobson
While many of the report's predictions paint a grim picture of humans' impact on the planet and the consequences that will have going forward, the IPCC also found that so-called tipping points, like catastrophic ice sheet collapses and the abrupt slowdown of ocean currents, are "low likelihood," though they cannot be ruled out.
About this photo: In this Tuesday, July 20, 2021 file photok the Staten Island Ferry departs from the Manhattan terminal through a haze of smoke with the Statue of Liberty barely visible in New York. Wildfires in the American West, including one burning in Oregon that's currently the largest in the U.S., are creating hazy skies as far away as New York as the massive infernos spew smoke and ash into the air in columns up to six miles high.
Pope, patriarch and Canterbury abbot issue climate appeal in first-ever joint statement
AP Photo/Lefteris Pitarakis
The panel is composed of independent experts put forward by governments and organizations to provide the best possible scientific consensus on climate change.
Scores of scientists provide regular reports on a range of aspects of global warming that governments draw on when discussing what countries can contribute to curb greenhouse gas emissions and adapt to the impacts of climate change.
About this photo: In this Friday, Aug. 6, 2021 file photo, smoke spreads over Parnitha mountain during a wildfire in the village of Ippokratios Politia, Greece, about 35 kilometres (21 miles), north of Athens. Thousands of people fled wildfires burning out of control in Greece and Turkey on Friday, as a protracted heat wave left forests tinder-dry and flames threatened populated areas and electricity installations.
AP Photo/Lefteris Pitarakis
The panel is composed of independent experts put forward by governments and organizations to provide the best possible scientific consensus on climate change.
Scores of scientists provide regular reports on a range of aspects of global warming that governments draw on when discussing what countries can contribute to curb greenhouse gas emissions and adapt to the impacts of climate change.
About this photo: In this Friday, Aug. 6, 2021 file photo, smoke spreads over Parnitha mountain during a wildfire in the village of Ippokratios Politia, Greece, about 35 kilometres (21 miles), north of Athens. Thousands of people fled wildfires burning out of control in Greece and Turkey on Friday, as a protracted heat wave left forests tinder-dry and flames threatened populated areas and electricity installations.
