What is, and is not, climate “data”?

The word “data” is misused a lot in conversations and publications about climate change. How many times have you heard or read the phrase “future climate data”?

Data, according to the Webster-Miriam dictionary, is factual information (as measurements or statistics) used as a basis for reasoning, discussion, or calculation. It is something that was measured. Numbers, words, sounds, emotional responses can all be data, so long as they were observed and recorded. Without a time machine, there is no “data” about the future.

Future projections from climate models are not, strictly-speaking, data. A numerical model, whether a complicated computer model of the atmosphere or a Newtonian physics equation from high school, may rely on actual data as initial inputs. The numbers produced by that model are not data. They were not directly measured. They are predictions derived from inputting the measurements into a simplified representation of the system being studied.

To clearly distinguish between actual data and numbers produced by models, climate scientists usually refer to the numbers produced by a model as “model output”, or sometimes “model results”.

The line between data and output can sometimes be blurry. For example, the ocean temperatures from a remote sensing group like NOAA Coral Reef Watch are the result of an algorithm integrating a series of point satellite observations over a region or “grid cell”, and controlling for factors like clouds. It is therefore the output of a simple model, which is why it is common to refer to those values as “satellite-derived data” rather than “satellite data”.

And if you really decompose the way much “data” is physically measured, you will find the line between data and output disappear entirely. Often the instrument, whether a simple thermometer or a complicated fluorometer, used to make measurements itself relies on some embedded empirical relationship that translates a raw independent observation into the desired variable.

Regardless, the rhetorical confusion between climate “data” and climate model “output” is not just semantics. In some settings, people’s choice of wording reflects a real confusion about what climate science can do for the world.

One of the central challenges in helping the developing world adapt to climate change is the gap between the desire for precise information about the future and the uncertain, probabilistic projections that science can deliver. During workshops, research interviews and private conversations in the Pacific Islands, I often here laments that “we need the data”. The use of the word data to describe future climate projections exemplifies that gap. People want precise, down-scaled climate predictions for their island or village, not a probabilistic range for an entire region. People want science to deliver something – precise answers – that is not possible.

Explaining and demonstrating the difference between data and output can go a long way to bridging the gap between the ability and the demands of climate science.


The climate, coral reefs, and energy policy must learn to cope with commitment


Bleached corals, Fiji, April 2014

This week, the U.S. government announced it would be listing 20 coral species found in American waters as “threatened” under the Endangered Species Act. Part of the rationale is the threat posed by climate change and ocean acidification, a potentially groundbreaking policy move. What may be missed in this announcement is that the original proposal included a longer list of 66 coral species.

The decision begs a broad question. If we are considering the research on climate change and ocean acidification in the decision, then why not list all coral species as threatened?

The Coral Specialist Group of the IUCN, of which I’ve been a part, submitted a detailed comment to the U.S. proceedings. My meager contribution to the group’s terrific dissection of coral ecology and physiology was the argument that committed climate warming may alone be sufficient evidence for all coral species to be listed as threatened. Here is the excerpt, with wording vastly improved by my colleagues:

The projected increase in sea surface temperatures due to the physical commitment from the present accumulation of greenhouse gases due to anthropogenic activity, as well as the socioeconomic commitment (i.e. it is logistically impossible to instantly eliminate anthropogenic emissions, regardless of policy decisions, because of inertia to the existing energy system), is sufficient to cause frequent and higher magnitude heat stress for the majority of the world’s coral reefs by 2050 (Donner, 2009). The primary source of uncertainty in this forecast is the ability of the coral holobiont to acclimate and/or adapt to heat stress. The fact that the future abundance of coral species depends on a rate of adjustment to heat stress that is unprecedented in geological history should be sufficient to warrant a minimum status of threatened for all coral species.

The problem of coping with commitment, the title of that cited 2009 paper, was highlighted by a terrific new paper that happened to be released almost simultaneously with the U.S. coral decision. In “Commitment Accounting of CO2 emissions”, Stephen Davis and Rob Socolow calculate the committed emissions from the operation of new energy investments, like coal plants, over the expected lifetime of those investments (see Dot Earth for a lengthy discussion). They conclude that it would  be sensible to use committed emissions, rather than the annual emissions, to inform public policy.

The socioeconomic commitment or capital “lock-in” to future emissions has implications for everything from these species listings to oil pipeline decisions. We can’t perfectly project the future of each coral species, but we can say that the oceans are committed to physical and chemical changes which may be dangerous or fatal to corals. These changes do not guarantee widespread extinction or endangerment, given potential adaptability of many species and the potential refuges in the ocean, but certainly could classify as threatening.


June was the hottest month on record for the ocean

GCDC oceanThe  oceans in June may have set an all-time heat record, according to data from the U.S. National Oceanic and Atmospheric Administration (NOAA). The global average sea surface temperature may have topped 17 °C for the first time in any month of any year since 1880.

The NOAA State of the Climate analysis reported that last month was the warmest June on the planet since records began, thanks in large part to ocean warmth. It was the 7th warmest June on land but the warmest June in the ocean, with the highest departure from normal recorded in the dataset for any month.

The temperature of 17.04°C should be seen as an estimate, given the challenge of defining “normal” for the oceans. However, we can still say with some confidence June may have been the warmest month for the ocean since these records began.

The record ocean warmth is seen particularly in the tropical Pacific, where currents, winds and temperature measurements have scientists forecasting a possible El Nino event.


Concerns about global warming… since the 1930s

1101390102_400“Gaffers who claim that winters were harder when they were boys are quite right—except that the change is too small to be detected except by instruments and statistics in the hands of professional meteorologists. Weather men have no doubt that the world at least for the time being is growing warmer.”

- “Warmer World“, Time Magazine, January 2, 1939

Yes, that’s with a 1, 9, 3 and another 9. The suspicions of weather “men” of the time were correct. The world was warming, and it would eventually continue to do so.

This article came before the upward trend in global temperatures actually slowed for two decades, thanks to a combination of air pollution, natural variability and land use change. Concern about the warming climate waned somewhat, but scientists continued to study the physical impact of adding carbon dioxide and other greenhouse gases to the atmosphere. By the late 1970s, the consensus among scientists studying the climate was that a continued increase in atmospheric CO2 levels will continue to warm the planet.


The NHL may be on thin ice, due to climate change

A new sustainability report from the NHL warns that climate change affects “opportunities for hockey players of all ages to learn and play the game outdoors”.

The report on sustainability initiatives may look like a bit of greenwashing from a sports league whose business can involve air-conditioning large stadiums to refrigerator levels in southern U.S. cities during June in order to play a winter activity. Nevertheless, the effect of climate change on outdoor ice, and the culture of Canadians and northern Americans is a real concern.

Liberty02The “ice season” on lakes and rivers all across the Northern Hemisphere has been shrinking. One of the longest records is from Lake Mendota, in Madison, Wisconsin, where I went to graduate school. The lake may be most famous for this Planet of the Apes stunt, first done by students back in 1979.

Welcome to the newest sequel, Melting of the Planet of the Apes.

The Mendota ice season averaged 122 days long back when observations began in the 1800s (1885-1875 average). Thanks to climate warming, the ice season is now more than a full month shorter! The average winter over the past twenty years featured only 85 days of ice.

mendota-durThis coarse metric of ice duration only tells part of the story. A lake that once froze in its entirety may now have portions that remain unfrozen all winter. During the record short 2001-2 ice season, enough of Mendota and other neighbouring lakes remained unfrozen that I considered taking my kayak out in mid-February, just for the sheer novelty of paddling in the middle of a Wisconsin winter.

A 2012 study in Environmental Research Letters suggested the shrinking ice trend extends even to artificial outdoor skating rinks. Using rink officials’ rules for deciding when the weather is safe enough to start the ice, scientists calculated that the skating season had shrunk over the past fifty years across Canada.

If the world continues on this greenhouse gas emissions trajectory, learning to skate on an outdoor rink may become a thing of the past, as will a number of key economic activities, like traveling safely by vehicle across the roadless, lake-dotted landscape of northern Canada. In a few more decades, when we’re on to the thirtieth Planet of the Apes sequel, the UW students may have to haul Miss Liberty out on pontoons.

The NHL is smart to be concerned about climate change. A favourable climate is foremost among the reasons that hockey – and watching hockey – is so fundamental to Canadians, and also Minnesotans and Wisconsinites. As the climate changes, culture may too, as we warn in this video. Kids may be less likely to get interested in skating and ice sports… or parents may be less likely to drag their crying kids to the indoor rink to practice.  Next thing you know, they may be playing and watching other sports.


Is El Niño on the way?

Following on a study by my former student Sandra Banholzer and I about the influence of different types of El Niño on global temperatures, I sat down with UBC Public Affairs to answer some questions about the possible return of El Niño this winter.

When should we start to see El Niño develop and how will the average person notice it?

El Niño typically develops during our fall and reaches peak strength during our winter and early spring. Scientists are watching conditions in the Pacific Ocean to check early suspicions that a new figure4event is on the way.

El Niño itself begins far away in the equatorial Pacific. A reversal of winds and currents brings unusually warm waters to an area between the coast of South America and the International Date Line. This is like dropping a huge rock in a stream. The warm waters release so much energy into the atmosphere that the normal flow of air is diverted, affecting weather all over the planet.

If a strong event develops, people across Western and Central Canada should see an unusually mild, dry winter and spring. On the other hand, people across parts of the southern U.S. should see unusually wet conditions. 

Will climate change play a role in strengthening this El Niño?

Climate change affects everything that happens in the atmosphere and the ocean. The jury is still out on exactly how climate change affects the development of El Niño events.

One thing is certain: as the planet has warmed, El Niño events have also warmed. Our research shows that, all else being equal, an El Niño event today is warmer around the world than an identical event 100 years ago.

How could El Niño affect global agriculture and fishing?

El Niño is no joke. Regional heat and drought brought by a classic “Eastern Pacific” El Niño can be devastating to farmers in southern Africa, India, Southeast Asia, Australia, the Pacific Islands, and even the Canadian prairies. The warm El Niño waters also choke off the supply of nutrients to the great fisheries off the coast of South America. We’d all see the effect in global food prices.

One silver lining may be California. El Niño rains could offer a respite from the intense three-year drought that has crippled production in the Central Valley.

Will a potential El Niño affect global temperatures in the coming months?

In general, El Niño events are expected to cause a spike in global average temperature. But not all El Niño events are created equal. Research led by my former student Sandra Banholzer shows that only the classic events with the ocean warming in the eastern Pacific–as last happened in 1997/1998–definitely lead to an increase in global average temperature.

Since then, El Niño events have been more of the “Central Pacific” variety, which are not necessarily warm globally. The supposed “pause” in global warming over the past 15 years is nothing of the sort. The planet has been warming, but thanks to these naturally variable conditions in the Pacific, more heat than usual has gone into the ocean.

The overall global warming trend is so strong that even a weaker El Niño is enough to break global temperature records. This past May was already the warmest May in recorded history. If the overall Pacific  pattern flips in the coming months, bringing a strong classic El Niño, we’re likely to shatter global temperature records.


Finding the balance between science and values in public engagement about climate change

Researchers in the public eye have always struggled to find a balance between representing their results and being effective communicators. This was the subject of my recent essay in Climatic Change.875735-130928-kudelka

One solution, proposed by Roger Pielke Jr., is to be an “Honest Broker of Policy Alternatives” who provides all the available information and options. Thus, rather than pre-selecting policy options to present, which inevitably involves some value judgements, the honest broker presents all the options and allows the decision-makers to reduce the scope of options.

It is a very reasonable solution to avoid having the researcher’s personal values influence their public statements.  From my article:

Failure to consider the possible influence of normative judgements on one’s thinking can lead to “covert” or “stealth” issue advocacy, in which scientists do not perceive the implied advocacy position in their research or public statements (Lackey 2007; Pielke 2007). This can undermine one’s objective of informing the public and policymakers about science and policy options.

Yet many science communicators question whether it is possible to be an honest broker, since the process of filtering and synthesizing research for public consumption involves value judgements. This is especially the case if the data or knowledge is incomplete; the researcher must make a judgement on what information to include.

A recent Twitter exchange with Pielke about his USA Today op-ed piece about hurricane trends and storm protection demonstrated just how hard it can be to control for all personal judgements*.

My suggestion the op-ed was misleading led to some back and forth about the research methods and wound to a close with an honest, funny tweet from Pielke: “Guilty — Most aspects of hurricane mitigation/preparation did not appear in my 700-word op-ed”

The tweet rightly pointed out the absurdity of my complaining about what is and is not included in a short op-ed. How could anyone fully explain the difficulty of estimating for the influence of storm preparation on the costs of storm damage, let alone all of the other research studies on the subject, in 700 words? Especially if you want those 700 words to be interesting enough to be accepted by a major newspaper?

Inclimate-change-science-v-politics-cartoon presenting the findings to the public, subjective judgements had to made about which findings warrant mention. Yet this is what someone playing the honest broker would seek to avoid. A partial solution to this dilemma, suggested years ago by Stephen Schneider and discussed in my article, is to make backup materials available. Today, a blog is an easy, accessible way to present the detailed evidence behind a position taken in a shorter public statement. Many of us, including Pielke, maintain blogs for that reason.

The problem is that we are still making choices in preparing that backup material. And, regardless, few people will ever read the material. We’re lucky if they read the whole op-ed, rather than just the headline! One outcome of this is that even if a researcher perceives herself or himself to be close to the honest broker ideal, others may not.

It is for these reasons that I encourage students to understand their motivations and personal biases, rather than strive to be objective automatons. We can’t remove all personal judgements. But we can strive to be honest with ourselves about our values and motivations and take them into account when engaging with the public. From my essay:

Finding a comfortable and effective position on the science-advocacy continuum requires analyzing ourselves with the same rigour we would use to analyze our data.We are scientists, but we are also citizens, voters, taxpayers, parents, children and homeowners. Research on science communication suggests that we must consider our knowledge, our motivation, our cultural values and our ability to reach different audiences in order to be effective at public engagement… This self-analysis is critical to making personal biases explicit and separate from scientific findings, to recognizing the limits of your communication abilities, and to protecting the hard-won public trust in science.


Global warming or Climate Change? It depends when and where

For years, people have argued over the best term to describe what is happening to the climate: global warming or climate change.

Market-savvy environmental groups have tried re-branding the issue entirely, producing terms like global heating, global weirding, global melting, climate crisis, climate disruption, climate chaos, springtime for CO2, climate farklempt, I’ve got some coastline in Florida to sell, etc. etc. The two originals, global warming and climate change, continue to corner the market like the Coke and Pepsi of the climate world.

A recent study by the Yale Project on Climate Change Communication found that global warming is more “effective” from a communications standpoint than climate change. Detailed public opinion analysis showed that “global warming” instills more concern about the issue and generates more motivation to take action.

The study also points out that the American public has for years used global warming far more than climate change, at least according to Google search data. However, if you dig further into the search data, you find some changing patterns.

Here is the U.S. search volume going back to 2004:

US search volume2Global warming certainly dominated the “aughts”. Since then, its relative use has declined. If we look at the ratio of searches for global warming and climate change in the above data, you see that word preferences have been changing:

US vs. Canada ratio in searchesIn the US (blue), the ratio has declined towards the 1:1 line (black), meaning that today there is close to an equal proportion of searches for global warming and climate change. That’s a big change since the mid-2000s, when global warming vs. climate change was like the Harlem Globetrotters vs. the Washington Generals.

In Canada, global warming was never nearly as dominant term north of the border. Climate change is now searched more often (52% of combined searches in 2014). This is no surprise to Canadians; the term climate change was adopted here years ago by most political parties and the media. That decision probably reflects the more moderate Canadian political climate, where people are more likely to trust authority, in this case, scientists and their preferred term. Granted, it also may reflect the actual climate; the term “global warming” may be scary if you live in Phoenix, but dreamy if you live in Winnipeg.

Narrowing the U.S. search data by region shows a huge geographic divide in the preferred term and the interest in the subject. For example, the next graph compares the search ratio for Texas and for the Bay Area. I tried using individual metropolitan areas in Texas and other conservative states, like Dallas-Ft. Worth or Houston, but none featured consistently high enough search volume for the past ten years. As it is, the Texas data had large gaps before 2007 (and one in 2008), when search volume was too low for the Google metric.

Texas vs. Bay Area ratio in searchesThe ratio is dropping in both Texas and the Bay Area. Texans, however, still prefer global warming by 2:1 or more over climate change. People in the Bay Area, however, are almost evenly split (52% global warming in 2014).

If you examine the overall data state by state, a clear pattern emerges. Republican-leaning states in the southeast and central U.S. have the highest global warming to climate change search ratio, whereas Democratic-leaning states have the lowest ratio. Texas is actually not even among the top ten in global warming preference. tableWashington DC is the only “state” where climate change is the preferred term, no doubt related at least in part to its use in government.

Harry Enten at fivethirtyeight came to a somewhat similar conclusion using data from U.S. Congress and cable news channels. Enten found that democrats prefer “climate change” and Republicans prefer “global warming”. He then argues that the Yale research would recommend the exact opposite:

If the polling is to be believed, Democrats, Republicans and the news channels they watch are actually having the opposite effect they are intending. We’ll have to see whether the Yale study makes them reverse course.

There are many unresolved questions, including whether the influence noted in the Yale Study is changing over time, and what that means for language choices. Does the choice of wording matter among people who are already motivated, like many in the Bay Area, or those whose attitudes are unlikely to change?  And would re-labeling by either party be so obvious to the public as to undermine the objective?

Regardless of the answers, one thing is clear from the search data. We are not paying nearly enough attention to ocean acidification:acidification search


Coral-eating starfish: An outbreak of Crown-of-Thorns Starfish in Kiribati

Last year, people in Butaritari Atoll, at the northern end of Kiribati’s Gilberts Islands began noticing these large spiny starfish depicted in the video above and photo below. The exotic-looking “crown-of-thorns” starfish, known as Acanthaster planci to scientists and latin-speakers in Brooklyn, is famous for preying on reef-building corals. Outbreaks of crown-of-thorns starfish can lead to drops in the amount of living coral on reefs, as has happened in places as varied as the Middle East and the Great Barrier Reef.

COTs off Betio, Tarawa

Crown of Thorns Starfish off Betio, Tarawa (S. Donner)

The Kiribati outbreak spread south to the central atolls of Abaiang and Tarawa over the past year. I filmed the shaky video above while conducting a coral reef survey in a, hmm, fast-flowing channel between the open ocean and the Abaiang lagoon (the word ‘drift’ is too passive to describe this dive; it was more of a ‘raging river’, ‘don’t hit anything’ or ‘I hope the boat can find us’ dive).

In the video, you can see the crown-of-thorns damage looks a lot like coral bleaching. One key difference is the spatial pattern. With a crown-of-thorns outbreak, as in the video, you often see isolated patches of whitened corals or large white circles on otherwise healthy looking mound or table corals.

We’re not absolutely sure what initiated this particular outbreak or any other outbreak for that matter. Marine scientists generally suspect that over-exploitation of the few predators of the crown-of-thorns, like triton or ‘conch’ shells, is the most likely cause of such outbreaks. It is also possible that nutrient pollution can indirectly promote the spread of the starfish through increased survival of their larvae. I hope that, if funding allows, we can at least track the long-term effect of the outbreak on the coral reefs of the island chain.