Tuesday, December 5, 2017

Arkansas: Awaiting a Wave

It has been a while since my last post, a lovely coincidence perhaps to Cupid's arrow and new family with a fellow blogger! šŸ’˜

Keeping true to this blog's goal to bring more indigenous Marshallese voices to the dialog surrounding climate change, here is---in my humble opinion---the most well done and certainly most artistic piece of the past year.

Awaiting a Wavecomes from THE WEATHER CHANNEL United State of Climate Change Series, which aims to share "a climate story for every state in the nation." This particular story belongs to the State of Arkansas and features "individuals, communities and businesses responding to the changes that are already happening in America, and how they’re preparing for the changes that have yet to occur." Quoted text from http://features.weather.com/us-climate-change/about/. Some of those individuals include: 

Chris Balos

Kathy Jetnil-Kijiner

Mark Stege

Melissa Lailan

Saturday, July 18, 2015

Tidying up a bit

Last year I saw an article in Science magazine that combines various statements from researchers in a way that "substantiates" the author's message that the climate change prognosis for atolls is perhaps not as bad as people living on atolls such as Kathy Jetnil-Kijiner and Ministry Tony deBrum have made it out to be. The debate has come up several more times in the media, and thus is worth further examination.

The author quotes Dr. Paul Kench of the University of Auckland as having stated that based on data from Jabat Island in the Marshall Islands, coral growth of 10-15mm per year will exceed the rate of sea level rise, thus allowing islands to grow and remain above water. Although this may indeed be the case--that the islands will remain above water--consider for a second how long it would take for 1) coral to grow, 2) be broken up and thrown onto intertidal reefs by waves and currents along with finer sediments, 3) and then for plants to take root and "cement" all these atoll building blocks together, and 4) finally for organic matter to decompose and provide a truly habitable environment for humans to survive. Atolls that are only allowed to build naturally up to the first step mentioned above, before having to build up yet again to keep pace with sea level rise, would not be fit for habitation without significant environmental engineering contributions.

I asked another atoll researcher named Dr. William Dickinson about it, and his take was that "The Kench study of Jabat shows nicely that islands could form near the highstand where buildup of rubbly storm ramparts on reef flats was sufficient (how that eventuality might or might not influence human settlement seems an open question to me, as such places would not be very attractive for habitation)."

Tuesday, June 23, 2015

An Introduction to Atoll Geography

The following is an excerpt from an unpublished thesis paper on “Atoll Habitability Thresholds” by M. Stege, Columbia University M.A. in Climate and Society Program Class of 2014. Above image courtesy Schmidt 2010.

An atoll is a ring of reef surrounding a central lagoon. There are often islands or sand cays interspersed within the reef.  Sand cays and vegetated islets are all that remain visible above water level during high, tide, and represent the only potentially habitable areas on an atoll. It was Charles Darwin who, while observing these unique landforms near the western coast of South America, first theorized how tiny polyps could form barrier reefs grown atop subsiding volcanic edifices (Darwin 1842: 109). Since then reef core and radiocarbon evidence from multiple atoll sites have confirmed Darwin’s theory, and expanded on the important role that sea-level fluctuations due to tectonic- and glacial-controlled forces have played in reef development. (Woodroffe and Webber 2014: 193) In other words, atolls are barrier reefs grown atop both subsiding volcanic edifices dating back tens of millions of years and episodic coral reef growth and discontinuity relative to sea level along millennial timescales. Note that This discussion of atolls does not address the handful of ‘emergent atolls’ and islands that have been lifted above sea level by tectonic forces. Only ‘subsiding atolls’ are discussed.

The last episode of coral reef growth and discontinuity (Figure 3, inset B) is uniformly evidenced among atolls starting around 8,000-10,000 BP with the inundation and submergence of present day atoll platforms due to sea level rise during the Last Interglacial. Coral growth appears to have lagged behind rising sea level during this time, until eustatic sea level stabilized at the ‘mid-Holocene highstand’ around 5,000-6,000 BP (Woodroffe and Webber 2014: 241-243). A period of explosive ‘catch up’ growth followed, during which different reef structures ‘caught up’ to sea level at different times and where margins of the atoll more exposed to wind-driven seawater nutrients generally grew fastest. Sea levels remained stable at the mid-Holocene highstand between 3,000-5,000 BP, a period marked in atolls today by the development of conglomerate platforms which formed after vigorous reef growth had ceased and lateral reef consolidation flourished. (Dickinson 2009: 4-8) These conglomerate platforms are the fossilization of reef, sediment, and boulder deposits, all cemented together to form a durable bedrock on which many of an atoll’s sand cays and islets are today “pinned.” (Dickinson 2009: 7) Excluding major storms these foundations make those pinned atolls resistant to wave damage, and therefore stable over the last few thousand years. As would be expected, these pinned islands are consistently most prevalent on the windward margins of an individual atoll. In lieu of projected sea level rise, Dickinson refers to ‘crossover dates’ when these conglomerate platforms start to become largely awash, as they were during the mid-Holocene highstand.

Looking towards the future, these conglomerate foundations that underpin the stable Pacific atolls are predicted to be become largely swept away by rising seas at some ‘crossover’ point, leading to the atolls being vulnerable to fair-weather wave attack. (Dickinson 2009: 7) When these crossover points occur, atoll erosion processes will become greatly accelerated, signaling a return to the atoll’s previously submerged and uninhabitable state a number of millennia ago. It is worth noting that around 2,000-3,000 BP a gradual ‘post-mid-Holocene sea level decline’ of about 0.8 meters occurred This was caused by oceanic siphoning wherein seawater was required to infill collapsed submarine arches and deepening continental shelves created by geological glacial mass loss (Miltrovica and Peltier 1991, 2002). Near consensus within the scientific community further holds with “very high confidence” that by the end of this century global sea levels will have risen by at least the observed global average since 1900 of about 0.24 meters plus ocean thermal expansion so closer to 0.62 meters (IPCC 2013). This is a conservative estimate of sea level rise which excludes escalations from glacial and ice sheet melt, which would raise the estimate to 1.2 meters (IPCC 2013), and even higher beyond the 21st century. (Joughin et al 2014, Rignot et al 2014) All this on top of several meters of natural sea level variability due to fair-weather ocean dynamics leaves little doubt that coral atolls will ultimately become uninhabitable due to sea level rise.

These “irrefutable, as well as shocking” realities of climate change, as pronounced by US Secretary of State John Kerry in his address to the 2013 Pacific Islands Forum, necessitate a coordinated and scalable response.

Monday, April 20, 2015

What Makes a Place Habitable? Or Livable?

That was the title of a short article I prepared for the M.A. in Climate & Society Program "Hot Topics" page.  Thank you to Brian Kahn, Wed Editor at Climate Central (and C+S alum) for his fine editing assistance.

Thursday, April 16, 2015

Atoll Habitability Thresholds

Its been four months since returning home from the Columbia M.A. in Climate and Society Program, and I am now doing field work to refine my thesis paper on atoll habitability thresholds with intentions to submit to my amazing team of advisors Michael Gerrard and Benjamin Orlove, PhD by July of this year. Wish me luck!

So some people have been asking what is this "habitability thresholds" thing? Well, the basic idea is that as ecosystems that make up areas of the world that different societies inhabit (e.g. atoll ecosystems for Marshallese) incrementally undergo physical and chemical changes due to climate change, the habitability of these ecosystems will incrementally diminish as well. Monitoring these changes and positively affecting their longevity is at the core of this idea.

One of the things I like about it so much is that it is very human focused, and reflects what society determines as acceptable. It is intentionally oriented to allow everyday citizens the opportunity to organize themselves around the process of understanding how climate change affects their lives and ecosystems, and then to act on that information. I believe that potential climate-displaced communities can be empowered in spite of the disempowering phenomena of climate change, and I believe it can be done by framing climate impacts, adaptation, and resilience around internationally recognized, locally refined, concrete measurements of habitability.

It is going to be a wonderful journey of discovery into climate science communication, and I am encouraging people with an interest to delve more into the concept and its demonstration in other settings (e.g. mountainous community settings in Nepal) as well.

Monday, November 3, 2014

Naan ne am Dede

"Your mommy, daddy, bubu, jimma, your country, and your President too -- we will all fight." 

Those are just some of the words still reverberating around the world from poet/activist Kathy Jetnil-Kijiner who opened the UN Climate Summit on behalf of all of the civil sector including the non-profit she and her cousins and friends founded in the Marshall Islands called JoJiKuM. 

  • Kathy addresses the UN Climate Summit, Sept. 23, 2014 on YouTube
  • Kathy's poem "Dear Matafele Peinam" to her daughter on YouTube
  • Statement and poem by Kathy Jetnil-Kijiner at Climate Change Summit 2014

    MilaƱ Loeak, daughter of the Marshall Islands

    Earlier this month a group of Pacific island warriors paddled traditional canoes into the world's largest coal port in a blockade. One of the protesters was quietly spoken MilaƱ Loeak, daughter of the president of the Marshall Islands.