Arctic sea ice extent is one of the most iconic indicators of climate change, but we usually give it most attention during the summer melt months. Nonetheless, I try to do a quick catch-up around the beginning of March, which marks peak extent. And this is what we see (Source: National Snow and Ice Data Center here; click for larger image):
Generally, winter ice is not a good predictor of summer ice extent, so I wouldn’t read too much into the fact that we are currently hitting new historical March lows in terms of what will happen this coming summer. That said, what we see in the above chart is still part of the general picture of new climate records being made across the board–especially in northern latitudes where warming is amplified.
The NSIDC is also hosting a series of stunning animated NASA satellite images that illustrate the changing nature of Arctic snow cover, vegetation and frozen ground as well as sea ice extent. The frozen ground page has this inset chart showing the general thaw (click for larger image):
This, in turn, is increasing fears relating to methane release, although as I blogged about here, I still see this as a lesser risk than general CO2 emissions. The Global Carbon Project also has a good backgrounder on methane (here), including a methane budget showing sinks and sources (click for larger image):
At present, we have more to fear from ruminants, rice, landfills and fossil fuels, than from hydrates and thawing peat bogs.
Returning to sea ice, the ‘go to’ site is Neven’s “Arctic Sea Ice Blog” I’ll be checking in regularly to see if what we are seeing now with Arctic sea ice is just a blip or harbinger of another big melt season. Neven has also just highlighted a disturbing Ocean Geographic Magazine photo essay by Jenny Ross that is worth checking out. It’s a surreal and unnerving experience to witness the planet change dramatically before our eyes.