Climate change news of the day

Decreasing Arctic albedo boosts global warming

Arctic Sea Ice Blog,

A new paper in PNAS, called Observational determination of albedo caused by vanishing sea ice, reminds me of scientific work Peter Wadhams published a year and a half ago wherein he showed Arctic ice melt is 'like adding 20 years of CO2 emissions'. He based this assertion on calculations, as can be read in thisBBC article from around that time.

This new paper by Pistone et al., however, is based on observations (as it says in the title) and similarly concludes that the "decrease in albedo is equivalent to roughly 25 percent of the average global warming currently occurring due to increased carbon dioxide levels"

I've taken this last quote from a livescience article. Here's more:

Since as early as the 1960s, scientists have hypothesized that melting sea ice amplifies global warming by decreasing Arctic albedo. Researchers have since devised climate models to demonstrate this phenomenon but, until now, nobody had relied entirely on satellite data to confirm this effect through time. [See Stunning Photos of Earth's Vanishing Ice

]

Now, scientists based at the University of California, San Diego have analyzed Arctic satellite data from 1979 to 2011, and have found that average Arctic albedo levels have decreased from 52 percent to 48 percent since 1979 — twice as much as previous studies based on models have suggested, the team reports today (Feb. 17) in the journal

Proceedings of the National Academy of Sciences.

The amount of heat generated by this decrease in albedo is equivalent to roughly 25 percent of the average global warming currently occurring due to increased carbon dioxide levels, the team reports.

"Although more work is needed, a possible implication of this is that the amplifying feedback of Arctic sea ice retreat on global warming is larger than has been previously expected," study co-author Ian Eisenman told Live Science.

Previous models of Arctic albedo have suggested the reflectiveness of white cloud cover could potentially mitigate a portion of albedo loss due to melting ice; but these new observations show that cloud cover has had a negligible effect on overall Arctic reflectivity, the team says.

While Arctic sea ice will not likely return to 1979 values in the near future, the ice does change from year to year and might still experience some comeback this century, though the extent to which this might happen remains unclear, Eisenman said.

Read the rest here.

Here's another quote from the September 2012 BBC article mentioned above:

The melting ice could have knock-on effects in the UK. Adam Scaife, from the Met Office Hadley Centre told Newsnight it could help explain this year's miserable wet summer, by altering the course of the jet stream.

"Some studies suggest that there is increased risk of wet, low pressure 

summers over the UK as the ice melts."

There may be an effect for our winters too: "Winter weather could become more easterly cold and snowy as the ice declines," Mr Scaife said.

The increased risk of wet summers in the UK has shown its ugly face already in recent years. As fellow blogger Chris Reynolds shows on his Dosbat blog, 4 of the 10 wettest summers since 1910 all occurred in the last 7 years. The chance that this is due to natural variation, is 0.14%.

In fact, Chris says: "The UK is experiencing cooler wetter summers, likely as a result of sea ice loss. And this has lead to damaging flooding events in 2007, and 2012. This is not happening by chance, it is climate change, ongoing and causing damaging consequences to lives, property and agriculture."

Tewkesbury, in Gloucestershire, after the floods in July 2007. Photograph: Getty Images

Nevertheless, there's a lot of ongoing brouhaha in the deniosphere over the Met Office giving conflicting forecasts. It could be that what the Met Office isn't getting, and fake skeptics will probably never (want to) get, is that the very real risk for now is that weather systems get stuck because of changes in the jet stream.

Coincidentally, the BBC published another article a couple of days ago,explaining how this works:

The meandering jet stream has accounted for the recent stormy weather over the UK and the bitter winter weather in the US Mid-West remaining longer than it otherwise would have.

"We can expect more of the same and we can expect it to happen more frequently," says Prof Francis

The jet stream, as its name suggests, is a high-speed air current in the atmosphere that brings with it the weather.

It is fuelled partly by the temperature differential between the Arctic and the mid-latitudes.

If the differential is large then the jet stream speeds up, and like a river flowing down a steep hill, it ploughs through any obstacles - such as areas of high pressure that might be in its way.

If the temperature differential reduces because of a warming Arctic then the jet stream weakens and, again, like a river on a flat bed, it will meander every time it comes across an obstacle.

This results in weather patterns tending to becoming stuck over areas for weeks on end. It also drives cold weather further south and warm weather further north. Examples of the latter are Alaska and parts of Scandinavia, which have had exceptionally warm conditions this winter.

Perhaps the most spectacular example has been on Svalbard in the last 30 days (besides the fact that Svalbard is circumnavigable in February!) where the average temperature was -1.0 °C, 15.0 °C above the normal. This is Europe's northernmost territory, just 10 degrees latitude from the Pole. According to NOAA all of the Arctic Circle could be heading towards this kind of anomaly as the century progresses.

See that black line towards the bottom? That's the 1961-1990 average

So, when you get easterly cold and snowy, you keep getting easterly cold and snowy. When you get westerly storms and rainy, you keep getting westerly storms and rainy, as some folks in the UK have been noticing this winter.

Again, from the BBC article.

With the UK, the US and Australia experiencing prolonged, extreme weather, the question has been raised as to whether recent patterns are due to simple natural variations or the result of manmade climate change? According to Prof Francis, it is too soon to tell.

"The Arctic has been warming rapidly only for the past 15 years," she says.

"Our data to look at this effect is very short and so it is hard to get a very clear signal.

"But as we have more data I do think we will start to see the influence of climate change."

Prof Francis was taking part in a session on Arctic change involving Mark Serreze, the director of the US National Snow and Ice Data Center in Colorado.

He said the idea that changes in the polar north could influence the weather in middle latitudes - so-called "Santa's revenge" - was a new and lively area of research and somewhat controversial, with arguments for and against.

"Fundamentally, the strong warming that might drive this is tied in with the loss of sea-ice cover that we're seeing, because the sea-ice cover acts as this lid that separates the ocean from a colder atmosphere," Dr Serreze explained.

"If we remove that lid, we pump all this heat up into the atmosphere. That is a good part of the signal of warming that we're now seeing, and that could be driving some of these changes."

Which brings us back again, full circle. Or perhaps I should say full meander.

Canada’s Arctic ice caps melting rapidly since 2005, according to documents

Ice floes float in Baffin Bay above the Arctic circle as seen from the Canadian Coast Guard icebreaker Louis S. St-Laurent on July 10, 2008.

Photograph by: Jonathan Hayward/The Canadian Press/Files , Postmedia News

Vancouver Sun,

18 February, 2014

OTTAWA — Glacier monitoring conducted by the federal government in Canada’s High Arctic shows the shrinking of ice caps that started in the late 1980s “has accelerated rapidly since 2005” and is part of a “strongly negative trend,” according to internal government documents.

The federal government data raise a number of questions about climate change in Canada’s North and what the melting ice caps mean for the country’s economy and environment in the future.

A memo requested by the deputy minister of Natural Resources Canada (NRCan) — and obtained by Postmedia News under access-to-information legislation — highlights what the federal government acknowledges are rapidly melting ice caps in Canada’s Arctic over the last nine years.

The data were obtained through NRCan’s Climate Change Geoscience Program, which monitors annual glacier mass fluctuations and sea level changes at sites across the Canadian High Arctic.

The federal government maintains glacier monitoring sites in the Canadian High Arctic for four ice caps: Devon, Meighen, Melville and Agassiz.

“Glacier monitoring conducted by the Earth Sciences Sector (ESS) in Canada’s High Arctic indicates that shrinking of ice caps started in the late 1980s, and has accelerated rapidly since 2005,” says an October 2013 memo to NRCan’s deputy minister, who reports to federal Natural Resources Minister Joe Oliver.

Preliminary data and observations — including on Arctic sea-ice coverage, upper atmospheric temperatures and field camp observations — indicate 2013 was cooler than the recent trend.

While the ice melt in 2013 doesn’t appear as bad as recent years, “it does not significantly alter the strongly negative trend observed since 2005 for this region,” say the briefing materials.

David Burgess, research scientist and glaciologist with Natural Resources Canada, explained that since 2005 there has been a persistent high-pressure system over Greenland, which has acted to draw in more warm air from southerly latitudes and contributed to a warming High Arctic.

This same kind of system didn’t develop in 2013, which may explain the cooler temperatures last summer, he said.

Federal data show the Devon ice cap’s northwest sector has lost 1.6 per cent of its mass since the 1960s, the Meighen approximately 11 per cent of its mass and the Melville about 13 per cent, he said. However, approximately 30 to 40 per cent of the ice mass lost has happened since 2005.

“Since 2005 it has enhanced quite significantly,” Burgess said in an interview.

The main consequence of shrinking Arctic ice caps is increasing sea levels, he said, which can impact Canadian coastlines depending on their resiliency to erosion and inundation.

Green Party Leader Elizabeth May, a former senior policy adviser to the federal environment minister in the Mulroney government, said the federal information on melting ice caps is “very troubling” but also not surprising because other international data have reached similar conclusions.

All Canadians should be concerned about climate change in the Arctic, she said. Along with directly impacting Inuit hunting, melting Arctic ice also will contribute to more extreme weather events in Canada such as droughts and flooding, she said.

“What’s shocking is that the internal documents reflect this information. The government of Canada can’t claim it doesn’t know or isn’t being warned, doesn’t understand that we are rapidly losing ice in the Arctic,” May said.

“Yet, it (federal government) is basically in a state of willful blindness to a major threat to the future of the country.”

Canada signed onto the Copenhagen Accord in 2009 and committed to reduce the country’s greenhouse gas emissions to 17 per cent below 2005 levels by 2020. However, Environment Canada’s latest emissions trends report released last fall projects Canada will slowly drift away from that target as the economy grows, unless more is done to reduce emissions.

Greenhouse gas emissions from the oilsands, the fastest growing source of carbon pollution in Canada, increased approximately 62 per cent between 2005 and 2011, to 55 million tonnes of CO2 equivalent emissions, from 34 million tonnes.

Oilsands emissions are projected to nearly triple between 2005 and 2020, to 101 million tonnes, according to Environment Canada.

Since coming to power in 2006, the Harper government has repeatedly promised to introduce greenhouse gas regulations for the oil and gas sector. However, Prime Minister Stephen Harper and successive environment ministers have repeatedly delayed those rules.

The data from Natural Resources Canada on melting ice caps support what other international assessments have concluded in recent months.

Data compiled by the National Snow and Ice Data Center, based at the University of Colorado Boulder, revealed that summer Arctic sea ice in 2013 was more than one million square kilometres below the average observed between 1981 and 2010.

Also, the Intergovernmental Panel on Climate Change reported in fall 2013 that “human influence has been detected” in the warming of the atmosphere and ocean, reductions in snow and ice, in global mean sea level rise as well as changes in some climate extremes.

The report, approved by most governments around the world, including the Conservative government, concluded human activity — largely through greenhouse gases released from the consumption of fossil fuels as well as deforestation and other land-use changes — had “very likely contributed to Arctic sea ice loss since 1979.”