Life as a climate change poster child: the new Scientific American article about Kiribati

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???????????????????????????????I have a feature (“Fantasy Island”) in the latest issue of Scientific American and accompanying online slideshow about the reality of sea-level rise in Kiribati.

The article summarizes the complicated science of sea-level rise in coral islands and the even more complicated politics of being a poster child for the impacts of climate change on the developing world. In reflecting on years of research on the ground and on (and in) the water, I try to provide an antidote to all those well-meaning but generally inaccurate pieces of popular disaster porn written about remote island nations like Kiribati and Tuvalu.

If you are interested in what actually is happening in places like Kiribati, I encourage you to buy the issue. An excerpt:

A North American or European traveling to Kiribati may as
well be stepping through a wormhole into another universe. Combine
that naïveté with the reserved nature of the Kiribati people,
the custom of deferring to outsiders, the legacy of countless
past i-Matang asking about climate change and the lack of local scientific
capacity to verify claims, and a naturally flooding village
becomes a victim. Add in the geopolitics—the legitimate need for
a tiny country lacking agency on the world stage to raise awareness
of a threat to its existence—and the exaggeration about the
impacts of sea-level rise can look intentional, whether it is or not.
As my friend Claire Anterea of the Kiribati Climate Action Network
says, “This is not a story that you will just journalize in one
week or two weeks.”

The article is  a testament to all the wonderful people in Kiribati that I have interviewed and worked with over the years, as well as to Mark Fischetti and the editors at Scientific American, who were willing to embrace a story about the incredibly important but less glamourous nuances of climate change.

Corals suggest El Niño may become more frequent

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By Jessica Carilli, Assistant Professor UMass Boston

IMG_5126

The author at work

In a warming world, key ocean-atmosphere processes, like the El Niño / Southern Oscillation, are expected to change. An important question is whether the frequency or nature of climate oscillations like El Niño will change in the future.

During El Niño, trade winds that normally blow warm surface waters from east to west across the equatorial Pacific Ocean weaken. The extra-warm surface waters that normally pile up in the west, called the Warm Pool, slosh back towards the east, shutting off upwelling off South America and reducing fishery productivity there. Rainfall patterns also change, moving to the east over the central Pacific and causing droughts in the west. El Niño also has global knock-on effects, like higher rainfall in California and drought in Australia.

In 2010, Simon Donner and I went to the Gilbert Islands, in the Republic of Kiribati, to collect core samples from large coral heads with the intent to learn how climate and the local coral reefs had changed over the past century.

Corals build their calcium carbonate skeletons from seawater, and in the process record changes in their environment – like water temperature and salinity – within the chemistry of their skeletons. Coral skeletons also have rings like trees, so assigning dates to the resulting skeletal environmental records is straightforward.

Gilbert Islands study region map

Butaritari is near the northern edge of the Gilbert group of Kiribati

The Gilbert Islands sit near the eastern edge of the Warm Pool, and are particularly sensitive to a recently discovered variant of El Niño, called El Niño Modoki or central Pacific El Niño. These events seem to be increasing in frequency, which makes this region particularly interesting.

Along with a team of researchers in Australia, we reconstructed water temperature and salinity at Butaritari, in the northern Gilbert Islands, from 1959-2010 and compared trends to other Pacific coral records. The gradient in water temperature from east to west across the Pacific is intrinsically linked to an atmospheric circulation cell called the Walker Circulation, comprised of the trade winds at the surface, rising warm air and rainfall in the west, and sinking, cool dry air in the east.

The records from Butaritari indicate that waters there have not warmed as much as water farther east along the equator. This means the west-east water temperature gradient has weakened over the past half century, and that the Walker Circulation – which breaks down during El Niño events – is weakening.

A weaker Walker Circulation in turn means that El Niño events will be more likely to occur. We could therefore be in for a future of increased El Niño events, which has consequences for fisheries, farming, and freshwater availability – not to mention increased likelihood of natural disasters like flooding and wildfire in some parts of the world.

The original publication can be accessed here or contact Jessica for a PDF.

Warming El Niños on a warming planet

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According to the World Meteorological Organization, this year is on pace to be the warmest in recorded history. Whether or not 2014 is awarded the gold, silver or bronze in the global warming’s equivalent of the 100 m dash will probably depend on the temperature dataset. The precise placement of any one year on the medal standings is, of course, immaterial to the broader issue of the longer term trend, described beautifully by Eric RostonENSO-temps-v2-wTrends-638x431.

What is remarkable to many observers is that a record might be set without the help of a “full El Niño”, to use the WMO’s term. In the last few decades, global average surface temperature records have generally been set by a combination of the long-term warming trend and the bump from everyone’s favourite Latin American weather nickname. An increasingly common way to plot global average surface temperatures is with additional labels for El Niño, La Niña and neutral years, as was done in the WMO report and this figure from Skeptical Science. The take-home message – El Niño, La Niña, neutral, it is all warming.

The labeling is the tricky part, for two reasons. First, El Niños normally develop and peak over the “boreal” or northern hemisphere winter, which means they span two calendar years. There’s usually a few months lag between the development of El Niño and the global temperature effect. Thus, for the global temperature analysis purposes, the “El Niño” year is the year after the onset of the event. The best example is the 1997/98 event which helped bump 1998 to a warmest year gold medal.

Second, there’s no one perfect way to classify El Niño events. For example, in the Skeptical Science plot, 2005 is classified as an El Niño year. In a plot in the WMO report, 2005 is classified as a neutral year. These conflicts arise with “weak” El Niño years because different groups use different classification systems. The U.S. agencies NOAA and NASA disagreed as to whether 2004/05 was an El Niño event.

The suggestion that El Niño events be divided into types or flavours may address some of this potential disagreement. The recent paper led by my former student Sandra Banholzer concluded that the global average surface temperature is anomalously warm – statistically-speaking – during the canonical or traditional “Eastern Pacific” El Niño events like 1997/98, but not during “Central Pacific” events or “Mixefig2 - banholzer and donnerd” events. A more nuanced classification system allows 2004/05 to get status as El Niño-ish, but not a classic El Niño.

There are a variety of ways to perform the classifications and it is safe to say that the scientists involved do not agree on the “best” method. Whatever method is used, the underlying surface warming trend is the same. As is clear from this figure from the recent paper, the warming trend is robust.

NOTE: We will have a poster on this subject at AGU on the afternoon of Wednesday, December 15th, 2014.

A blast from the coral past

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20141117_140418This blue coral specimen was collected during the U.S. Navy expedition to Bikini Atoll, in advance of the famous hydrogen bomb tests and forced evacuation of the Bikinians.

After years essentially collecting dust in someone’s basement, a group of corals from that expedition were donated to the California Academy of Sciences in San Francisco.

I took the photo during a recent visit to give a talk and to tour their incredible collections.

Message from communications research: Climate change is real. Repeat. Repeat again.

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There is an ongoing feud about value in communicating the scientific consensus on climate change to the public. One side argues that we need to talk about the consensus in order to raise public awareness about climate change. A new review article by John Cook and Peter Jacobs (also described in the Guardian) reviews the evidence for “consensus messaging”.  The counterargument, proposed by Dan Kahan and others, is that talking about consensus will increase political polarization about climate change.

A recent paper by Kahan called “Climate Science Communication and the Measurement Problem” suggests the disagreement among communications researchers is related to the “contamination of education and politics with forms of cultural status competition”. It is a fascinating paper with a lot of important findings. But I wonder if, deep in the data, there may be evidence that the drumbeat of climate change news and outreach campaigns has actually been effective.

The core result of the paper is described by the following figure:

Kahan 2014 - Fig 7 - no legendIf people were rationally assessing scientific information, higher science comprehension would translate into higher perceived risk from climate change (left panel). Kahan’s experiments find the opposite for people on the right of the political spectrum (red, right panel). That’s been the headline: for conservatives, better knowledge of climate science might mean less concern about climate change.

In other words, when people go beyond the basics, opinions become polarized. That is not very surprising, given that someone on the right of the political spectrum with greater interest and/or ability in science who looks for information about climate change may head to right-wing media and blogs, which often house an alternate universe of “facts” about climate change.

What is more surprising are the results for people with low “science comprehension”.

Why are people with low science comprehension on both the left and the right of the political spectrum perceiving moderate to high risk from climate change? If people’s views on climate change are defined more by their cultural identity than by the facts of the case, why would people on the right of the spectrum with low science comprehension have even moderate concern about climate change?

This opinion about the risk from climate change must derive from something. It isn’t a detailed knowledge of the science, or the problem. Otherwise, the people would fall elsewhere on the graph. It also isn’t their community. Their community, if defined correctly, generally believes the risk from climate change to be low.

What’s happening? Perhaps there has been enough mention of climate change in the public domain, whether on the news, in private conversations, etc., that even those who pay scant little attention to science have been able to develop some level of concern about climate change.

It may be that, current polarization aside, the much-maligned information deficit model has actually worked, at least with very basic information, and in the way political messaging works. Years of repeating the general facts of the case – climate change is real, caused by humans, and poses a risk to the future – appears to have created a basic public consciousness about climate change.