BBC's Frozen Planet: On Thin Ice

From the offset I want to state that the BBC has not (unfortunately) given me any incentive to endorse their series of Frozen Planet narrated by David Attenborough. Focused on the Arctic and Antarctica, this series has mainly being orientated to the biology in these frozen landscapes with the sixth episode dedicated to the Inuit tribes that live on the ice shelves. However, the last episode entitled 'On Thin Ice', was dedicated to the impacts that climate change is having in these polar regions, of which certain aspects were highly relevant to this blog.

It is important to acknowledge that the documentary does not state where it gets its statistics for ice melt rate and increasing air temperatures, or the uncertainties associated with these models. Despite this the use of time-lapse imagery and different case studies mean it expresses historic and future changes in a way that is easy to understand for those who may have a limited knowledge on climate change.

In the episode, David Attenborough states that the thickness of the Arctic icesheet has decreased by around half since 1980 and is now only a couple of metres in places. Attenbourgh then goes on to add that if the current trends continue, in the summer these areas may become open ocean in the next few decades with similar observations occurring in the Antarctic. Containing 75% of the world's freshwater, it is predicted that  Antarctic surface temperatures have increased by 3°C which is ten times the average rate for the rest of the Earth. Although David Attenborough states that the rise in temperature itself is unlikely to cause significant melting of the Antarctic Ice sheet (unlike the Arctic), rising temperatures could cause ice shelves that are containing the icesheet to melt at the iceshelf-ocean interface. If these iceshelves melt then the icesheet will advance to meet the ocean where it could potentially be melted by the warmer ocean surface water below. Surveys have indicated that iceshelves are melting six times faster that historic rates, with seven major ice shelves such as Larsen B in 2002 and more recently the Wilkins iceshelf already breaking up (The Guardian, 7th December, 2011). This 'wave of melting' that David Attenborough refers to is moving south towards the poles as is anticipated to start to affect the ice shelves holding back the Antarctic continental ice sheet in the next few decades.

The most fundamental point that the episode highlights is the impact that the melting will have on the global climate. As I have previously discussed, ice melt will significantly affect the albedo of the surface, and the replacement of ice by the darker open ocean will cause a positive feedback accelerating temperature rise in these polar regions. Attenborough also states that ice on land (including alpine glaciers) are more important than sea-ice as it can significantly alter sea levels. This emphasises the point that I have been trying to convey about the impacts that glaciers can have on not only a local but also a global scale.

Also, unlike animals such as the Adelie penguin (Pygoscelis adeliae) which can currently migrate further towards the poles, animals such as the snow leopard (Unica unica) in the Himalayas may be under a greater threat to climate change as they are more restricted in the extent that they can migrate to higher altitude locations. This draws attention the biological impacts that climate change may have on the ecosystems in alpine environments and goes beyond the scope of this blog. However, changes to biodiversity and ecosystem functions will likely have impact on local alpine communities as seen in the changing practices of native Inuit tribes in the Arctic.

If you can spare an hour amongst all of the Christmas shopping and present wrapping then I would strongly suggest watching this episode of Frozen Planet. Not shown in the US because of its strong support for climate change, this episode provides an easy introduction into the affect that climate change has had on our polar regions, and as David Attenborough states, 'it is apparent that animals are already adapting to climate change, the question now is can we?'.

To watch the episode go to the BBC website.
For more information, there is also an interactive website produced by the Open University which provides further details about the making of the series and photos from the series.

Reference:
Rees, D (2011) 'Frozen planet: capturing the Wilkins ice shelf in full collapse', The Guardian, 7th December 2011.