Climate and the Peninsula

 I mentioned climate change in passing in an earlier entry and I wanted to take this opportunity to elaborate on this subject as it relates specifically to the Antarctic Peninsula.  Climate change is such an enormously complex issue scientifically, politically, ethically, socially, and geographically, that it is impossible to make generalizations that answer the scariest and also the simplest questions about the future.  I have known that this controversial topic is one of the most difficult to communicate, but it has actually been the cruise ship passengers that have reminded me of its intrigue and mystery among general audiences that don't live and breath these thoughts and words daily. 
       Our boss, Hugh Ducklow, is a master of climate change communication and I never would have suspected it.  He has a scientific presentation about changes they have observed on the peninsula that had me on the edge of my seat because he makes it into such a good story.  I will not be able to reproduce the story here (I lack his practice), but I will try to explain the highlights of the picture that has started developing from the information collected in the very project that I am a part of.  I will spoil one punch line to emphasize how fascinating this system is.  The western side of the Antarctic Peninsula is the fastest-warming place on the planet.  It seems like a self-centered statement coming from an antarctic researcher, but the records don't lie - average winter air temperatures have already risen 11 degrees F in the last several decades.  While this is a huge number, I find it interesting (and wonderfully scientifically pure) that Hugh speaks about the data and his curiousity before he taints the topic with socio-political dramatics and fear-driven woes.  (This description should not leave you with the impression that he is unconcerned.  Rather, it seems as though he can turn his science and social switches on and off, which is an ability that I admire).  
        If I have learned one thing about Antarctic ecology, it is that sea ice matters.  As it turns out, sea ice matters a great deal.  Sea ice is important for all of the animals in the food web, but most importantly, it is absolutely essential for the teeny-tiny plants that support all life in the ecosystem.  The microscopic plants are eaten by vegetarian sea-insects such as itty-bitty shrimp and krill, which are in turn eaten by sea birds such as penguins.  And we all know what eats penguins!  That's right, the seals. Imagine sea ice as a very thick, retractable roof in a greenhouse that is designed to give the plants the perfect amount of light and warmth (or cold).  Clearly, it is not simply the presence or absence of a roof that the plants depend on, but their growth changes depending on how thick the glass is and how many days of the year it covers them.  Sea ice shades the plants underneath during the winter but the thick layer of freshwater sitting at the sea surface also prevents the water from mixing.  Mixing is neither good or bad, but these plants are used to a specific amount of mixing, just as they are adjusted to a specific amount of sun and nutrient-rich food.   
       So, what happens when temperatures warm up?  Simply put, less sea ice forms.  In some places where there used to be permanent sea ice, it now breaks up during the summer.  In this case, the plants are getting more light than they used to and are actually growing more than they used to.  More plants means more krill.  In other areas, such as our own Arthur Harbor, the story is changed slightly.  Here the sea ice traditionally only covers the surface in the winter.  Now there is no ice to keep the surface calm, so the winds mix up the water and the plants are sent much deeper than they are used to being.  And just like people, plants need to take in more energy than they use, and once they sink to where it is too dark for them to get energy, they die.  This is a problem for krill, people who try to study and collect krill, and mostly the penguins.  More complicated, it is not bad for all penguins.  The Adelies have suffered the most within recent decades, but the gentoo and chinsrap penguins have moved in from south america and find these krill patterns very well suited to their breeding season.   
        One common misconception (possibly the biggest), is that all of these small changes will even out in a geographic region, or even across the globe.  Unfortuantely for the Adelie penguins and other long-lived animals such as tigers or bears, old habits die hard.  Penguins return to the same historical nesting colonies for decades and if those areas no longer overlap with krill hotbeds, they cannot simply move in search of more food.  This is a complex idea known as the match-mismatch hypothesis that is well-known in ecological circles.  It happens everywhere and at unpredictable rates.  This is the largest fear for ecologists worldwide, not because they are all tree-hugging, panda-loving idealists, but because of the natural products and processes that we depend on.  Of course, no one wants to see the world's last polar bear, of course, but there are so many other interesting and complex implications of change. 
      Not to delve too deeply into these issues, but one last misconception is that this mismatching would find balance again, similar to a pendulum that always finds equilibrium.  This would certainly be true except for two main problems: time and space.  These changes are happening so fast and we have not left animals and plants the space to move to where they find it most comfortable.  The issue of space is irrelevant for Antarctica, so I will return to the topic at hand. 
        The tip of the peninsula is slowly becoming warmer and wetter while the southern reaches are becoming colder and drier (bad news for those dull conversations at McMurdo!).  The reason that it is warming so quickly here is the strong ocean current that continuously circles the continent unimpeded by land.  The water stores a great amount of heat and energy from the friction and runs right into the peninsula finger!  An interesting point that Alice made clear for me is that the reason Antarctica became so cold in the first place (hundreds of millions of years ago) is that this strong current completely isolates it from the weather patterns that are driven by winds nearer to the equator.  This current alone shows how complex and interconnected everything is, from weather to sun to seals - it's a very old system.
       My intentions with this post were no more or less than to show how hugely complex one relatively small area of the planet can be when talking about change.  Complexities abound and this is what is hardest to explain when someone asks a pointed question about the ice core carbon dioxide or how fast the glaciers are melting.  So, I think if I could have one wish or suggestion for anyone thinking about these difficult issues now and into the future, it would be to step back and think simultaneously about the intricacy of even the smallest areas and the interconnectedness of the world at large.  It makes me think, wow.