Arctic Amplification

Various processes, including albedo change (the change in reflectivity when ice and snow are replaced by open land or ocean), amplify the warming which is observed in the Arctic. Yet the situation is complicated. Cloud cover can change, which also affects reflectivity and can reduce or increase Arctic warming. Atmospheric patterns can likewise change, as can the state of the atmosphere in general. Overall, although we know that the Arctic is warming faster than the planet as a whole, how great this amplification will be in the future remains uncertain.

CO2 Velocity

As I mentioned in an earlier post, I recently modified my smoothing program so that it would record not only the estimated smoothed value, but the estimated smooothed velocity (rate of change) as well. I’m always a little leery of a new analysis method, there could be some unanticipated quirk of its behavior, but let’s apply it anyway to estimate the momentary rate of change (the velocity) of CO₂ on about a 5-year time scale.

Snow+Ice (by request)

Several readers requested an approximation of the total climate forcing caused by the loss of ice and snow during the satellite era. OK

Snow

During the recent discussion of ice albedo and how strongly the warming influence of northern hemisphere sea ice loss outweighs the cooling influence of southern hemisphere sea ice gain, it was mentioned by several readers that snow loss in the northern hemisphere is also a major warming influence, a potent amplifying feedback of global warming.

Oh Shit

Climatesight has a post which is both fascinating and disturbing. It reports recent research that carbon emissions from melting permafrost may have a much bigger impact than had previously been accounted for.

Sea Ice Insolation

I recently posted about the difference in sea ice changes between the Arctic and Antarctic. A comment appeared from Dave Burton which included some nonsense trying to claim that the Antarctic sea ice gain is more important for climate than the much greater Arctic loss. He happened to be the same Dave Burton associated with “NC-20,” a group which tried to get the North Carolina state legislature to outlaw any official use of sea level rise forecasts other than the extrapolation of a linear trend based on past observations.

Sea Level Rise along the Atlantic Coast of North America north of Cape Hatteras

One of those commenting on the paper by Shepard et al. in the journal Natural Hazards was Albert Parker. Rather than dissect his comment on Shepard et al., let’s take a look at another paper he recently published in that same journal, Oscillations of Sea Level Rise along the Atlantic Coast of North America north of Cape Hatteras, (2012, Nat Hazards, DOI: 10.1007/s11069-012-0354-7).

Unnatural Hazards

Christine Shepard has recently published her first peer-reviewed paper as lead author, Assessing future risk: quantifying the effects of sea level rise on storm surge risk for the southern shores of Long Island, New York (Shepard et al. 2012, Nat. Hazards, 60:727–745 DOI 10.1007/s11069-011-0046-8). Such a first is usually (and it should be) a moment of triumph for a young scientist.

Poles Apart

As most of you are aware, Arctic sea ice has shrunk dramatically over the last several decades, because of man-made global warming. This year it has broken the records for lowest area, lowest extent, and lowest volume. Perhaps more to the point, those records were broken not by a little — not even by a modest amount — the were broken by a helluva lot. Yes, a hell of a lot. The loss of Arctic sea ice has been nothing short of astounding.

Arctic Sea Ice: Turning Points

Perhaps the most obvious “turning point” in Arctic sea ice is the stunning decline at the summer minimum of 2007. The annual minimum extent for every year since then has been less than for every year before then. To many, it marks a new era for the ice pack covering the Arctic ocean. The post-2007 era has been makedly different from what happened before.