Entries tagged with “climate variability”.


In the New England I knew as a child, people commonly paraphrased Mark Twain’s famous line “If you don’t like the weather in New England now, just wait a few minutes.” This was true year-round, but when it comes to rapidly changing temperatures, winter really had its moments. Most years, there seemed to be a day in the middle of January when the usual freezing days would give way to one that reached 50 or 60 degrees F. This prompted everyone to go outside in shorts before returning to the layers of winter for another three months. Why everyone had shorts at hand in the middle of January in New England is a regional mystery that remains unexplained.

When it comes to temperature, New England has always been a pretty variable place. When I moved back, I assumed it still would be. But after returning and living in the region for a year, that variability started to feel odd. For example, I became acutely aware of the surprising number of December days that reached the high 40s or low 50s, mostly because there is no indoor track in Worcester so I train outdoors all year (a note to the city of Worcester: Seriously? Nine colleges and lord-knows-how-many high schools, all looking for somewhere to train and race, and nobody thought to build an indoor track? 1). While the temperature is still marked by significant and relatively rapid changes, these temperature swings seem more drawn out than I remember. Where my understanding of variable temperatures was formed around a world marked by a day or two of outlying conditions followed by a return to expected temperatures, in 2017 October averaged 57 degrees Fahrenheit for the month, wildly out of line with even the 2010-present average of 52.

NOAA defines extreme temperatures as falling in the upper 10th percentile (for warm temps) or lowest 10th percentile (cold temps) across the time for which records were kept. In terms of heat, the figure below shows the percentage of days where the daytime high meets this definition of extreme. It is important to note that in the chart these extremes are relative to the month in question. In December, an extreme high is a temperature above 51.1 F, while in July it is above 87.1 F. Both are significant deviations from the norm, but the human experience of each is quite different.

In fact, the number of days marked by extreme/unusual high temperatures, just under 43 per year, has not changed since my childhood. However, as the chart shows, the distribution of these extremes throughout the year has changed. September has seen the greatest increase in these unusually hot days, which contributes to the sense of a longer summer season. On the other hand, the average number of days with extreme high temperatures in January and February has not changed much. We still have unusually warm periods in those months, but their frequency and duration is similar to that I knew as a child. March, June, and August are marked by fewer such days.

There has been a more dramatic change in the patterns related to extreme cold days – annually, there are now 26 fewer unusually cold days than seen in my childhood. This decline is visible in every month. August has more than three fewer unusually cold days, a change that means that today we see one such a day every five years. Along with overall increased average temperatures, and a longer duration and larger number of increased temperatures, this makes for a summer that feels more consistently summery.

There are four fewer extremely cold days in December, and these days now occur less than once a year. This is both a staggering change, but also a marker of a past that is now gone. Part of my identity is based on my ability to shrug off really cold temperatures, an ability borne of being sent outside to play regardless of the temperature throughout my childhood. Who from my generation did not make the mistake of coming inside, using the bathroom, and washing their hands under hot water too soon? If you have not done this, it really shocks the nerves and feels like someone is jamming dozens of needles into your hands. Generally, you make this mistake once. My kids are big Star Wars fans, but unless they concentrate on outdoor play during February, the warming temperatures mean they will probably not be reenacting versions of the Hoth scene from Empire Strikes Back as frequently as I did with my friends, and probably complain more when it is cold.

In my head, this image of my childhood home is still what winter should look like

The wild swings in temperature I recall from my childhood also appear to have become less frequent. There is a reason most New Englanders my age or older have an innate sense of layering in their wardrobes. That said, there’s also something very New Hampshire about a nostalgia for the days when you’d start sweating in your snowsuit because you needed it when you first went out, but it had since warmed up into the 50s while you were outside.

“Hey kid, if you’re big enough to sled, you’re big enough to help shovel the driveway!”

To better understand this change, I looked for days where the high temperature either increased or decreased by 20F or more from the day before. The charts below show what I found – overall, it appears that we see fewer of these swings now than in the past.

Where once there was an average of about 18 days per year where the temperature was 20 F warmer or cooler than the day before, today there are fewer than 13 days. As with most other temperature-related conditions, the deep winter period of January and February is much as it was in my childhood. Nearly every other part of the year has changed. For example, it appears the swings in temperature that I used to associate with March are being displaced into April and May. While July, August, and September rarely saw such swings in the past, they have now disappeared completely. Again, summer is becoming more consistently summery. Where November and December were once ground zero for this sort of day-to-day temperature change, today the temperature in these months has become more stable than in the period from January through April. Those warm days in December reflect high temperatures relative to my memory, but it doesn’t get as cold in December as it used to. Those temperatures feel unusually warm to me, but relative to current conditions they simply don’t qualify as extreme.

Once upon a time, you had to pack sweaters and jeans for a Salsbury beach vacation because even in early August you were going to get one of those days…

Even contemporary daily temperature changes are less pronounced than in my childhood. The chart below shows that the average day now operates in a somewhat smaller temperature window than in the past – across the year, the difference between the daily average high temperature and the average low temperature has shrunk by 1.3 degrees Fahrenheit since I was a child. This trend is true in every month, but very pronounced in October and December. Most of this change can be attributed to the fact that daily average low temperatures are rising faster than daily average high temperatures.

Taken together, this evidence suggests that, at least when it comes to temperature, the New England of “if you don’t like the weather, wait a minute” is going away. Since my childhood the weather has become a bit more predictable and a lot warmer. For a guy who prided himself on his resilience in the face of very cold and rapidly changing weather conditions, a resilience borne from a childhood outdoors in New England, this feels sad. It also challenges an identity I’ve carried throughout my adult life, which I lived almost entirely outside New England. I lived mostly in more temperate (if not tropical) climates. In those places I enjoyed being the New Englander, relatively unbothered by swings in temperature that made those around me complain. I took some pride in the ways in which my childhood had inured me to such discomforts. But now New England is warmer and, let’s be honest, just a little more boring when it comes to temperatures. My children are unlikely to develop quite the same sense of identity. Then again, this might be for the best. Compared to their father, they’ll be less insufferable when confronting cold or highly variable weather alongside those from warmer climates.

Notes:

  1. If you happen to have some capital laying around and are into track, I can help you spend it in Worcester – you are sure to make a mint, and I can stop freezing my ass off while trying to work out in January

Over the past year, I’ve been working with Mary Thompson (one of my now-former students – well done, Dr. Thompson) on a report for USAID that explores how the Agency, and indeed development more broadly, approaches the issue of gender and adaptation in agrarian settings. The report was an idea that was hatched back when I was still at USAID. Basically, I noticed that most gender assessments seemed to start with a general “there are men, and there are women, and they are different, so we should assess that” approach. This binary approach is really problematic for several reasons.

  • First, not all women (or men) are the same – a wealthy woman is likely have different experiences and opportunities than a poor woman, for example. Lumping all women together obscures these important differences.
  • Second, different aspects of one’s identity matter more or less, depending on the situation. To understand the decisions I make in my daily life, you would have to account for the fact that sometimes my decisions are shaped by the fact I am professor (such as when I am in the classroom), and other times where what I do is influenced by my role as a father. In both cases, I am still a man – but I occupy two different identity spaces, where my gender might not be as important as my profession or my status as a (somewhat) responsible adult in the house.
  • Third, this approach assumes that there are gendered differences in the context of adaptation to climate change and variability in all situations. While there are often important gendered differences in exposure, sensitivity, and adaptive capacity in relation to the impacts of climate change and variability, this is not always the case.

My colleagues in both the Office of Gender Equality and Women’s Empowerment (GENDEV) and the Office of Global Climate Change agreed that these issues were problematic. They enthusiastically supported an effort to assess the current state of knowledge on gender and adaptation, and to illustrate the importance of doing gender differently through case studies.

Mary and I reviewed the existing literature on gender and adaptation in agrarian settings, exploring how the issue has been addressed in the past. We also focused on a small emerging literature in adaptation that takes a more productive approach to gender that acknowledges and wrestles with the fact that gender roles really take much of their meaning, responsibilities, and expectations from the intersection of gender and other social categories (especially age, ethnicity, and livelihood/class). You can find a first version of this review in the annex of the report. However, Mary and I substantially revised and expanded this literature review for an article now in press at Geography Compass. A preprint version is available on the preprints page of my website.

The bulk of the report – and the part probably of greatest interest to most of my readers – are three case studies that empirically illustrate how taking a binary approach to gender makes it very difficult to identify some of the most vulnerable people in a given place or community, and therefore very different to understand their particular challenges and opportunities. These cases are drawn from my research in Ghana and Mali, and Mary’s dissertation work in Malawi. They make a powerful case for doing gender assessments differently.

This report is not the end of the story – my lab and I are still working with GENDEV and the Office of Global Climate Change at USAID, now identifying missions with adaptation projects that will allow us to implement parallel gender assessments taking a more complex approach to the issue. We hope to demonstrate to these missions the amount of important information generated by this more complex approach, show that greater complexity does not have to result in huge delays in project design or implementation, and ideally influence their project design and implementation such that these projects result in better outcomes.

More to come…

So, climate change and conflict is back in the media, seemingly with the strength of science behind it.  I’ve been a rather direct, harsh critic of some work on this connection before, at least in part because I am deeply concerned that work on this subject (which remains preliminary) might disproportionately influence policy decisions in unproductive or even problematic directions (i.e. by contributing to the unnecessary militarization of development aid and humanitarian assistance).  So, when CNN, the Guardian, and other media outlets jumped on a new paper in Science (sorry, paywalled) last week, and one of the authors was responsible for the paper I critiqued so harshly before, I felt compelled to read it – especially after seeing Keith Kloor’s great post on the issue. After reading it, I feel compelled to comment on it.

My response is lengthy, so for those on a time budget, I offer some takeaway points. The main post, with details, follows.

Takeaway points

  • The Hsaing, et al paper in Science makes claims that are much more nuanced than what is represented either in the press releases from Princeton and Berkeley, or in many of the media stories (especially the big outlets) about them.
    • The actual findings of the paper simply reiterate long-held understandings of the connection between climate change and conflict
    • These findings are, in summary:
      • The climate affects many arenas, including food supplies, markets, and employment. The climate affects each of these in different ways in different places.
      • Climate-related changes in one or more of those arenas could (but do not always) affect rates of conflict
      • Even when climate-related changes to these arenas do provoke conflict, the provocation can occur in any number of locally-specific ways
      • Therefore, all we can really say is that climate change might affect rates of conflict in different ways in different places in the future
    • We already knew all of this
      • The authors’ claims (as stated in this press release from Princeton) that this study was necessary to establish a causal relationship between changing climate conditions and conflict is based on a straw man of “people” who have been skeptical of “an individual study here or there.”
      • Much of the literature, and those working on this issue, have long accepted the idea of a complex link between changing climate/weather conditions and conflict. The real question is that of how climate variability and change contribute to rates of conflict.
      • The paper does not answer this question
  • The quantification of increased risk of conflict in the paper is problematic, as the authors appear to assume a constant relationship, year-to-year or season-to-season, between climate conditions and their influence on various drivers of conflict.
    • This assumption has long been discarded in studies of food security and famine
    • This assumption likely introduces significant margins of error to the findings of this paper regarding increased risk of conflict associated with climate change
  • The paper does not address the real research frontier in the study of conflict and climate change because it does not further our understanding of how climate variability and change result in increased risk of conflict
    • To the author’s credit, the paper does not purport to explain how observed climate variability and change are translated into conflict
    • The paper merely summarizes existing literature exploring this issue
    • The findings of the paper do not present an opportunity to adjust policy, programs, or diplomacy to avoid future conflicts, as they do not identify specific issues that should be addressed by such efforts.
    • To some extent, this makes the critique under #2 above irrelevant – the “risk of conflict” figures were never actionable anyway
  • Media coverage of this paper amounts to much ado about nothing new

 

Main Post

The Hsaing, et al paper bears little resemblance to the media stories written about it. It makes very measured, fairly contained claims about climate change and conflict that, if represented accurately in the media, probably would not have made for interesting stories. That said, the article deserves critical attention on its own terms so we can understand what, if any, new information is here.

First, I want to start with the good in this paper. This is a substantially more careful paper than the one I critiqued before, both with regard to its attention to existing work on the subject and to the claims it makes about the connections between climate change and conflict. The authors deserve credit for noting the long history of qualitative work on conflict and the environment, a literature often ignored by those conducting large, more quantitative studies. They also should be commended for their caution in identifying causal relationships, instead of basic correlations.

In my opinion, this much more measured approach to thinking about climate change and conflict has resulted in more nuanced claims. First, as the authors note:

“Social conflicts at all scales and levels of organization appear susceptible to climatic influence, and multiple dimensions of the climate system are capable of influencing these various outcomes.”

But later in the paper, the authors temper this point:

“However, it is not true that all types of climatic events influence all forms of human conflict or that climatic conditions are the sole determinant of human conflict. The influence of climate is detectable across contexts, but we strongly emphasize that it is only one of many factors that contribute to conflict.”

And in the end, the big summary (my emphasis):

“The above evidence makes a prima facie case that future anthropogenic climate change could worsen conflict outcomes across the globe in comparison to a future with no climatic changes, given the large expected increase in global surface temperatures and the likely increase in variability of precipitation across many regions over coming decades”

Every bit of this is fine with me. Indeed, had the reporting on this paper been as nuanced as the claims it actually makes…there probably wouldn’t have been any reporting on the paper. The hook “the climate affects a lot of things, and some of those things could affect rates of conflict, so climate change might affect rates of conflict in different ways in different places in the future” isn’t exactly exciting.

And this is where I have to critique the article. My critique has two sides, one intellectual and one from a policy perspective. They are closely linked and blend into one another, and so I present them both below.

Intellectually, I fundamentally question the contribution of this paper. In a nutshell, there is almost nothing new here. Yes, there appear to be some new quantifications of the risk of conflict under different climate situations, and I will return to those in a minute. But overall, the claims made in this paper are exactly the claims that have been made by many others, in many other venues, for a while. For example, the Office of Conflict Management and Mitigation at USAID put out a report back in 2009 (yes, four years ago) that reviewed the existing literature on the subject and came to more or less the same conclusions as this “new” article.  So I was a little bothered by the Princeton press release for this paper in which quoted lead author Solomon Hsaing several times, because I think his justification for the paper is based on a straw man:

“We think that by collecting all the research together now, we’re pretty clearly establishing that there is a causal relationship between the climate and human conflict,” Hsiang said. “People have been skeptical up to now of an individual study here or there. But considering the body of work together, we can now show that these patterns are extremely general. It’s more of the rule than the exception.

I’d love to know who the “people” are who think there is no relationship between climate conditions and human conflict. Critiques of the study of this connection (at least credible critiques) have not so much argued that there is no connection, but that the connections are very complex and not well-captured in large-scale studies using quantitative tools.  So, when Hsaing goes on to say:

“Whether there is a relationship between climate and conflict is not the question anymore. We now want to understand what’s causing it,” Hsiang said. “Once we understand what causes this correlation we can think about designing effective policies or institutions to manage or interrupt the link between climate and conflict.”

…he’s really making a rather grand claim for an article that just tells us what we already knew – that there is a connection between climate conditions and human conflict. And he is burying the real lede here…that the contribution we need, now, is to understand how these causal relationships come to be. This argument for “where we should go next” is also a bit grand, seeing as everyone from academics to USAID’s Office of Conflict Management and Mitigation have been conducting detailed, qualitative studies of these relationships for some time now because we already knew a) that there were relationships between climate and conflict and b) we needed to establish what caused those relationships.

Second, I feel this article suffers from a critical methodological flaw, in that the authors never address the variable coupling of climate outcomes and changes in even those drivers of conflict identified in the literature. For example, it is not at all uncommon to have market shifts take place seasonally, in a manner that can be either coupled or uncoupled with shifts in climate: that is, sometimes a bad rainy season damages local harvests and drives market prices for food up, while other times it could be a great rainy season and a very productive harvest, but factors on regional or global markets could still generate price spikes that end up limiting people’s access to food. In both situations, the people in question would experience a food stress, one closely linked to climate variability, and the other experience a food stress uncoupled from climate. This is why, as I argued back during the Horn of Africa Famine, drought does not equal famine. Famines are far more highly correlated to market conditions than climate conditions. Sometimes climate events like a failed rainy season can trigger a famine by pushing markets and other factors over key thresholds. However, we’ve also had famines in times of normal or even favorable climatic conditions for agriculture.

Simply put, the authors appear to assume a constant relationship between a conflict driver like access to food and the local/regional/global climate. To be fair, this seems to be a pretty prevalent assumption in the literature.  But to the point, this is a bad bet. As best I can tell, the authors have not managed to address the intermittent coupling of conflict drivers like access to food and markets with climatic conditions in their analysis. This, to me, casts significant doubt on their findings that risk of inter-group conflict will rise 14% at one standard deviation of temperature rise – in short, this is far too precise a claim for a study with such large margins for error built into its design.  My suspicion here is that the margin of error introduced by this problem is probably larger than their analytical findings, rendering them somewhere between weak and meaningless. And this, to be honest, was the only really original contribution in the paper.

Third (as I begin to pivot from intellectual to policy critique), while the authors claim to have focused on causal relationships (a claim I think should be tempered by my methodological concerns above), they cannot explain those relationships. I’ve made this point before: in the social sciences, causality is not explanation. Even if we accept that the authors have indeed established causal relationships between climate variability and change and the risk of conflict/rates of conflict, they do not know exactly how these changes in climate actually create these outcomes. This is clear in the section of the paper titled “Plausible Mechanisms”, in which the authors conduct a review of the existing literature (much of which is qualitative) to lay out a set of potential pathways by which their observed relationships might be explained. But nothing in this study allows the authors to choose between any of these explanations…which means that all the authors have really accomplished here is to establish, by different means, exactly what the qualitative literature has known for a long time. To repeat:

  1. The climate affects many arenas, including food supplies, markets, and employment. The climate affects each of these in different ways in different places.
  2. Climate-related changes in one or more of those arenas could (but do not always) affect rates of conflict
  3. Even when climate-related changes to these arenas do provoke conflict, the provocation can occur in any number of locally-specific ways
  4. Therefore, all we can really say is that climate change might affect rates of conflict in different ways in different places in the future

We already knew all of this.

At this point, allow me to pivot fully to my fourth critique, which comes from a policy perspective. People tend to see me as an academic, and forget that I served as the first climate change coordinator for the Bureau for Democracy, Conflict, and Humanitarian Assistance (DCHA) at USAID. I was Nancy Lindborg’s first climate advisor – indeed, it was in this role that I found myself first dealing with issues of conflict and climate change, as I was responsible both for briefing my Bureau’s leadership on these issues and guiding the programming of the Bureau’s dedicated climate change budget (some of which I directed into more research on this topic). In short, I do know something about policymaking and the policy environment. And what I know is this: this paper gives us nothing actionable to address. Even if I accept the finding of 14% greater risk of intergroup conflict at one standard deviation of temperature increase, what am I supposed to do about it? Without an explanation for how this temperature rise produces this greater risk, I have no means of targeting programs, diplomacy, or other resources to address the things that create this greater risk. In short, this paper tells me what I already knew (that climate variability and change can contribute to conflict risk) without giving me anything concrete I can work on. If I were still briefing Nancy, my summary of this paper would be:

  1. There is nothing new in this paper. Its key findings are those of CMM’s (four-year-old) report, and are already well-established in the literature
  2. The paper does not provide any new information about how climate change and variability might contribute to increased conflict risk, and therefore presents nothing new that might serve to guide future policy, programs, or diplomacy
  3. I have methodological concerns with the paper that lead me to believe that the rates of increased risk of conflict reported in this paper are likely stated with too much confidence. These rates of heightened risk should not be cited until put under significant scrutiny by the academic and policy community*.

In summary, the supportable parts of this paper are nothing new – it is a reasonable summary of the issues with establishing a connection between climate change and conflict, and a decent (if truncated) review of the existing literature on the subject (I’d suggest that a real review article of this subject would have to go wider and look at the conflict and environment literature more broadly). But it doesn’t say anything new that really bears up to scrutiny, and even if the “risk of conflict” figures are correct, the paper provides no information that might guide policy, programs, or diplomacy in a manner that could avoid such conflicts. For that information, we have to return to the qualitative research community, which has long espoused the same general findings as those in this paper.

The press releases from Princeton and Berkeley, and the more hyped of the media coverage we’ve seen around this paper (likely driven by those press releases) is much ado about nothing new.

 

 

*In my third point I am indeed taking issue with the peer review process that brought this paper to publication. I believe that Science wanted this paper for the same reason Nature wanted the last one: headlines. Let’s see how the findings here stand up to serious scrutiny.