(IPCC graphic of Arctic sea ice change from 2006 to 2080-2100)
For sea ice melt trackers, 2007 was a long, long time ago. Things were quite a bit different then, before that record year obliterated all past records for sea ice loss and made projections like the one above seem silly and quaint. Since these predictions were made, we’ve lost nearly 2 million square kilometers of sea ice — an area nearly the size of Greenland and melt rates indicate an end to Arctic sea ice by late summer within the next decade.
If such an event were to occur, it will happen more than 60 years ahead of IPCC predictions. As an aside, it is worth noting that the graph doesn’t represent what a small remnant of sea ice will probably look like. The actual north pole will be free of ice and all that remains will huddle against the north of Greenland for protection and insulation from the insults of heat from all directions.
As the record melt season of 2012 has continued to progress, more and more Arctic scientists are validating a melt trend that is devastating the northern polar sea ice. PIOMAS has been collecting data that shows a potential for sea ice disintegration by end of summer within the next 5-10 years. And this summer a team of British researchers validated PIOMAS findings using satellite data. Then, Cambridge professor and sea ice expert Peter Wadhams made a stunning prediction that most sea ice could be gone by 2015.
Now, the Norwegian Polar Institute is chiming in. The Arctic sea-ice big melt of 2012 “has taken us by surprise and we must adjust our understanding of the system and we must adjust our science and we must adjust our feelings for the nature around us”, says Kim Holmen, NPI international director.
“As a scientist, I know that this is unprecedented in at least as much as 1,500 years. It is truly amazing – it is a huge dramatic change in the system”, noted NPI’s Dr Edmond Hansen. The melt is “not some short-lived phenomenon – this is an ongoing trend. You lose more and more ice and it is accelerating – you can just look at the graphs, the observations, and you can see what’s happening.”
What has happened is that nature is moving the goal posts faster than scientists can establish them.
The heat we are seeing doing work on the sea ice now. What will happen to it once it has finished with the sea ice? It’s not just going to sit there in the ocean for decades and centuries. It’s going to go right to work on Greenland. And we can see that happening now. According to scientific reports, the tipping point for Greenland ice melt is between .8 and 3.2 degrees Celsius above pre-industrial average. We are at .8 C now. And the forcing of human climate change keeps pushing that number higher.
This summer saw a massive new record melt for Greenland and it’s really just the beginning.
IPCC findings were for a very mild sea level increase for the 21rst Century. However, with the sea ice melting so fast and Greenland and West Antarctica next in the line of fire, it appears that these break-downs are more and more likely to occur sooner. Possibly starting within this decade and intensifying through mid century. It is more likely that a 2 meter rise or greater will occur before 2050, if greenhouse gas emissions aren’t dramatically brought into check. And based on where we are now, it would take a major effort to remove carbon from the atmosphere to prevent sea level rises in excess of 1 meter by end of century.
As we’ve noted in previous posts, a 365-405 ppm level of CO2 is enough to melt both Greenland and West Antarctica and raise sea levels up to 75 feet. We are in this range now. Yet with current emissions and amplifying feedbacks from traditional carbon sinks, it looks like we are on track for between 450 and 550 ppm CO2 by mid-century. At 550 ppm CO2, there is enough heat energy in the atmosphere to take out all the ice sheets.
This is a very powerful forcing that will almost surely have gone to work substantially softening Greenland and West Antarctica by the period of 2040-2060.
The goal posts are moving swiftly and it is fair to say that human-caused greenhouse gas emissions are both knocking Earth out of its comfortable homeostasis as well as knocking the once static and slow-seeming study of climate into a period of rapid change.