Big Think Interview With James Hansen

James Hansen: Well, I'm Jim Hansen. I'm a climatologist. I work at NASA and also at Columbia University.

Question: What is a basic definition of climate change?

James Hansen: Yeah. Well, human-made global warming is caused by changes in the atmosphere which are due to burning fossil fuels, primarily. As we burn oil, gas and coal, this releases carbon dioxide to the atmosphere. And carbon dioxide absorbs heat radiation from the earth, and that traps the heat radiation and makes the planet a bit warmer. So we notice that the world has warmed up about one and one-half degrees Fahrenheit in the last century, with most of that warming in the last 30 years.

Question: What is the latest conclusion on CO2 emissions?

James Hansen: Yeah. Well, there's now 387 parts per million of CO2 in the atmosphere. A hundred and fifty years ago it was 280, so it's increased by 107 ppm. What we thought a few years ago was that it would probably be safe to let CO2 go as high as 450 parts per million. The reason we thought that was that we know that there were previous periods in the earth's history called interglacial periods -- we're now in a warm interglacial period, which we have been in for about 12,000 -- but there were prior periods when the earth was warmer than it is now, and the planet was still pretty much the way it is now. And we thought that -- it was then about a degree or so Celsius, which is about two degrees Fahrenheit, warmer than it is now -- and we thought that might be okay to be that warm. And 450 parts per million would probably take us to that sort of a climate.

But what we now realize is that during those prior warm periods, sea level was about six or seven meters higher than it is now. And also we see what's happening with the current 387 parts per million. That's already enough that the arctic sea ice is melting, mountain glaciers all around the world are melting, which is going to affect the fresh water supply for billions of people. The climate zones are shifting, so the southwest United States and Mediterranean region are becoming hotter and drier; likewise Australia. So you see increased forest fires and reduced water supplies in those regions. Coral reefs are already under stress; many of them are going to be lost if we continue with increasing greenhouse gases. So we realize already that 387 is actually too large. About 350 parts per million is a more realistic target, and that means we're going to have to phase out use of coal over the next couple of decades if we want to be able to get back to 350 parts per million.

Question: Are you critical of the use of fossil fuels?

James Hansen: We simply -- if we look at the fossil fuels and we see how much carbon there is in oil, gas and coal -- and by far the largest is coal -- and we know that we're going to use the oil and the gas; they're very convenient fuels. The big pools are owned by Russia and Saudi Arabia. They're certainly going to sell that gas and oil. If we want to be able to get back to 350 parts per million, it's this huge coal reserves that we're going to have to leave in the ground. Or we could burn the coal and capture the CO2 and put it back in the ground, but that's very difficult. We're going to have to move beyond fossil fuels sometime within the next century anyway, so why not do it now and preserve a climate that will allow our children and grandchildren to have the same sort of planet that we enjoyed, and with all of the species that are still on the planet? [00:05:09.00]

Question: How can we wean ourselves off of coal?

James Hansen: Yeah. There's one huge step, and that is putting a price on carbon emissions. It's really that simple. If we put a gradually increasing price on carbon emissions by putting a tax at the source, at the mine or at the port of entry where the fossil fuel is imported to our country, then as that price rises, then energy efficiency, renewable energies, nuclear power -- the other forms of carbon-free energy -- can compete more effectively against the fossil fuels. But in order for the public to accept this, and in order for the public to have the money to invest in a new vehicle and insulating their home, we have to give all of this money to the public.

If we put a price on carbon equivalent to $1 a gallon of gasoline, that would generate $670 billion in one year in the United States. If you return this to the public, to legal residents of the United States, that would be $3,000 per adult legal resident. And if you give half a share to children, up to two per family, that's $9,000 per family with two or more children. So that would give the public the money to make the changes in their lifestyle that are needed to move us off of fossil fuels into a cleaner future, because right now the fossil fuels are the main source of air pollution, which is killing in the United States about 40,000 to 50,000 people per year; worldwide a much larger number than that, because the pollution is much worse in China and India than it is in the United States. So we have many reasons to want to move beyond the fossil fuel era.

Question: What is the likelihood of this actually happening?

James Hansen: It could happen very easily if our governments would move in that direction. And by the way, this has happened; it is happening now in British Columbia, Canada. They have imposed a carbon tax with the money returned to the public. They do it via a decrease in payroll taxes. I would rather see a dividend because half the people are not on a payroll; either they're retired or they're out of work. But you could use, say, half of it for a payroll tax deduction and half of it for a dividend. 

Question: How would nuclear power work on a large scale?

James Hansen: Well, nuclear power -- the kind of nuclear power we have now is called second-generation nuclear power. It's comparable in cost to coal. Once you have the nuclear power plant, then the fuel is very inexpensive, so nuclear power is quite inexpensive. But it's difficult in the United States to get a nuclear power plant built, and it takes so many years that it drives the cost up. So now in England they've realized that they will need to have nuclear power in the future, so they've put a limit -- once a government commission decides on where the power plants will be built, the public will have one year to object to this and possibly get some changes. But they can't drag it out six or seven years, the way it happens in the United States, because that drives up the price tremendously.

And there's also the possibility for fourth-generation nuclear power. That's a technology which allows you to burn all of the nuclear fuel. Presently, nuclear power plants burn less than 1 percent of the energy in the nuclear fuel. Fourth-generation nuclear power allows the neutrons to move faster, so it can burn all of the fuel. Furthermore, it can burn nuclear waste, so it can solve the nuclear waste problem. And the United States is still the technology leader in fourth-generation nuclear power. In 1994, Argonne National Laboratory, now called Idaho National Laboratory, was ready to build a fourth-generation nuclear power plant, but the Clinton-Gore administration canceled that research because of the antinuclear sentiments in the Democratic Party. Well, we still have the best expertise in that technology, and we should develop it because it's something we could also sell to China and India, because they're going to need nuclear power. They are not going to be able to get all of their energy from the sun and from the wind.

Question: What is the most effective approach to alternative energy?

James Hansen: Well, the most effective one is energy efficiency. We waste a lot of our energy. We can get vehicles that get more miles per gallon. There are many ways to improve energy efficiency. In fact, some states are twice as efficient as other states, just because -- fossil fuels were so cheap we just didn't pay attention to how effectively we were using them. But in addition, there are renewable energies: solar energy, wind energy. And I think that nuclear power has to be part of the solution, because at this time it's the only alternative to coal for base-load electrical power. And we do now have the technology for much safer and more efficient nuclear power, as compared to the old versions that were used in the past several decades.

Question: Will the cap-and-trade proposal curb emissions?

James Hansen: Yeah. You know, Obama is still perhaps our best hope, but he's going to have to study this problem and understand it. Presently, his approach is to let Congress debate it and make their horse trading, and end up with some sort of compromises with the polluters. And then we end up with this cap-and-trade and offsets, and a completely ineffective system. But this situation, in which we can see what we are doing to future climate and what the implications will be for young people -- we're in danger of sending them into a situation where dynamical system will be out of their control. But this -- the intergenerational injustice of that is -- this problem is analogous to that faced by Abraham Lincoln with slavery, or Winston Churchill with Nazism. It's not a problem where you can compromise. Lincoln couldn't say, well, let's reduce the slaves by 50 percent. You can't compromise on this; we have to phase out the carbon dioxide emission over the next several decades. And frankly, that means phasing out coal emissions. And this cap-and-trade system doesn’t do it at all.

Question: Why do you feel many politicians support the bill?

James Hansen: Well, they are -- they're taking the easy way out. They're allowing the polluters to write the bill. The Waxman-Markey bill in the House is 2,000 pages long. Do you think that Representative Waxman wrote this? No, this is written by the polluters; and even by environmentalists -- there are good points in those bills also. It's filled with the polluters' point of view and some environmental things to increase solar power, for example. But that's not going to solve the problem. It's just like the old Kyoto Protocol approach. They have to face the fundamental issue: as long as fossil fuels are the cheapest energy, then they are going to be burned, and their use will continue to increase. You have to face it. That's what the lawmakers are not facing, and that's what President Obama has got to understand. So the only way you can address that is by putting a rising price on the carbon emissions. Then the alternatives -- the renewable energies, energy efficiency, nuclear power, anything that doesn't produce carbon -- will compete more effectively, and those which are most effective will begin to win economically.

Question: Do you feel anybody in Washington sees this?

James Hansen: Yes, there are people in Washington who get it. There is one bill that was introduce in the House which had a gradually increasing carbon price. The Democratic Party -- it was introduced by a Democrat, and I'm sorry I can't think of his name of the moment -- but it was conveniently ignored by the Democratic Party. We've got to have an open discussion of this. I think the public is not excited about this issue the way they were about health care. But we need to have that kind of an open discussion so that we see what the alternatives are, because this approach that is being pushed by the Democratic Party is a disaster.

Question: Can you describe your recent activism efforts?

James Hansen: Well, activism is going to be necessary, it seems. We have to draw attention to the intergenerational injustice in climate change. You know, I went to Massachusetts because I recognized that they're a very progressive state, and I had hoped that -- you know, we have to find one state that will take an approach that works. And that means a carbon price, with the money, 100 percent of the money, returned to the public. There's a province in Canada that 's doing that, but people in the United States don't pay that much attention to what's happening in British Columbia, Canada. If we had one state that would pass a law with carbon price and 100 percent dividend to the public, then I think people would wake up, and they would say, hey, this works, and it's to the advantage of the public, not to the polluters.

 Question: Did you make any progress?

James Hansen: But the problem was that Massachusetts had already been listening, and they had begun to take action a year ago. What action? Cap-and-trade. So getting them to change direction at this point seems very difficult. I'm going to write something soon, trying to find one state -- one out of 50 states -- that is in a position and has leaders that can understand what is needed and may be willing to serve as an example for the other 49 states.

Question: What states do you feel are progressive enough to embrace this change?

James Hansen: Well, there are states that are progressive and have been trying quite hard. California's a good example, but again, I think they have already taken initial steps in a different direction. So I haven't looked carefully enough to say what is the best candidate state.

James Hansen: Well, I have children and grandchildren, and I've decided that I am going to try to make clear what the implications are. And I certainly have every right to do that. And I think that scientific colleagues are now much more willing to go along with that. If you go back a few decades, scientists tended not to like it if other scientists spoke up publicly. But the scientific community recognizes this is an issue where we have to educate the public.

Question: What will life be like if carbon emissions continue to grow?

James Hansen: Well, if we allow emissions to continue at a high rate, in this century we're going to see ice sheets begin to disintegrate. And one of the things I write about in my book is the effect that will have on storms, because as Greenland begins to release more fresh water, cold fresh water, and Antarctica does, what it does is cool the North Atlantic Ocean and the southern ocean, and that increases the temperature gradient between low latitudes and middle and high latitudes. And that will increase the strength of storms that are driven by horizontal temperature gradients. So our children can look forward to increasing storms. And with a rising sea level that is going to lead potentially to a very chaotic situation, because once you have hundreds of cities in the situation analogous to what happened in New Orleans, then we've got an economic situation that's just out of control globally.

In the long run, if that really happened, as I point out in the book, over centuries, we could actually get a runaway greenhouse effect, and then that's it for all the species on this planet. And as I try to point out, there's no practical way to escape from this planet; we can't even transfer one species to another planet. I discuss the monarch butterfly and just how complex it is. And for us to hope that we could transplant life from our planet to another planet is really unrealistic. [00:21:59.17]

Question: What is the runaway greenhouse effect?

James Hansen: A runaway greenhouse effect means once the planet gets warmer and warmer, then the oceans begin to evaporate. And water vapor is a very strong greenhouse gas, even more powerful than carbon dioxide. So you can get to a situation where it just -- the oceans will begin to boil, and the planet becomes so hot that the ocean ends up in the atmosphere. And that happened to Venus. That's why Venus no longer has carbon in its surface. Its atmosphere is made up basically of carbon dioxide because it had a runaway greenhouse effect. Now the earth, it can go unstable either toward a cold climate or toward a hot climate. And the earth has had a runaway snowball earth situation. This happened most recently about 700 million years ago. The earth froze all the way to the equator.

So these runaway situations can occur. We've never had a runaway greenhouse effect, because if we did, that would have been the end. Once -- that's a permanent situation. In the case of a snowball earth, when the earth becomes ice-covered, then the planet can escape from that situation because volcanoes continue to go off, but the weathering process is greatly reduced. So volcanoes put carbon dioxide into the atmosphere, and it builds up more and more until there's enough to melt the ice. But we can't push the planet off of the runaway greenhouse end. That's the end for everybody if we do that.

Question: How long would this take to occur if we stay on this path?

James Hansen: Well, you would have to -- first of all, you'd have to melt the ice sheets, and that takes a while. The Antarctic ice sheet is a couple miles thick. But with continued rapid increase in greenhouse gases, that -- you could melt the ice sheets in less than a century. And then things start to get hotter and hotter. So over a period of several centuries it would be conceivable to have a runaway greenhouse. That would also require bringing into play what we call the methane clathrates or methane hydrates. We already observe in the tundra region in Canada and Siberia that as the tundra is melting, methane, frozen methane, begins to be released. And methane is another powerful greenhouse gas. And there have been times in the earth's history when the methane hydrates on the continental shelves melted and went into the atmosphere and caused global warming of six to nine degrees Celsius, which is 10 to 18 degrees Fahrenheit. So if you add that on to the carbon dioxide warming and the water vapor warming, you could begin to push the planet into a very different state.

Question: How can businesses help fight climate change?

James Hansen: Well, businesses -- you know, Congress does listen to businesses. And they need to -- you know, our -- I call them the captains of industry -- they're the ones who are -- their support is needed to solve this problem. And they need to put some pressure on Congress to do the things that are needed rather than asking for special favors. Business leaders would actually like Congress to set a schedule for changes that are needed, and they would actually favor -- most of them, I think, would favor a gradually increasing, well established carbon price rather than this cap-and-trade which can oscillate, and you don't know how the impacts will be on your business. But if they knew what the increasing price on carbon was going to be, then they can make the changes to their business that are needed in order for them to continue to make money or even make more money; begin to invest in those things that are carbon-free.

Question: Are any businesses doing particularly well in this?

James Hansen: Well, there are businesses that are beginning to emphasize energy efficiency. We need -- in order for that to really work, there does need to be a carbon price. And there are some industries that are beginning to tell Congress it makes more sense to have a carbon tax and dividend than it does to have cap-and-trade.

Question: What are these industries?

James Hansen: Well, you know, one of them, which makes people nervous, is -- the CEO of Exxon Mobil said carbon tax is a good approach. Well, that makes people nervous, because Exxon Mobil has been one of the biggest producers of carbon dioxide. But in fact, that is what's needed. So we're willing to take support from wherever it comes.

Question: Why do you think they support it?

James Hansen: Well, I think that businesses do prefer an approach in which they know what is going to happen. With cap-and-trade you don't know what's going to happen.

 Recorded on November 30, 2009

 

A discussion with the NASA and Columbia University climatologist.

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Why compassion fades

A scientific look into a ubiquitous phenomenon.

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Sex & Relationships

One victim can break our hearts. Remember the image of the young Syrian boy discovered dead on a beach in Turkey in 2015? Donations to relief agencies soared after that image went viral. However, we feel less compassion as the number of victims grows. Are we incapable of feeling compassion for large groups of people who suffer a tragedy, such as an earthquake or the recent Sri Lanka Easter bombings? Of course not, but the truth is we aren't as compassionate as we'd like to believe, because of a paradox of large numbers. Why is this?

Compassion is a product of our sociality as primates. In his book, The Expanding Circle: Ethics, Evolution, and Moral Progress, Peter Singer states, "Human beings are social animals. We were social before we were human." Mr. Singer goes on to say, "We can be sure that we restrained our behavior toward our fellows before we were rational human beings. Social life requires some degree of restraint. A social grouping cannot stay together if its members make frequent and unrestrained attacks on one another."

Attacks on ingroups can come from forces of nature as well. In this light, compassion is a form of expressed empathy to demonstrate camaraderie.

Yet even after hundreds of centuries of evolution, when tragedy strikes beyond our community, our compassion wanes as the number of displaced, injured, and dead mounts.

The drop-off in commiseration has been termed the collapse of compassion. The term has also been defined in The Oxford Handbook of Compassion Science: ". . . people tend to feel and act less compassionately for multiple suffering victims than for a single suffering victim."

That the drop-off happens has been widely documented, but at what point this phenomenon happens remains unclear. One paper, written by Paul Slovic and Daniel Västfjäll, sets out a simple formula, ". . . where the emotion or affective feeling is greatest at N =1 but begins to fade at N = 2 and collapses at some higher value of N that becomes simply 'a statistic.'"

The ambiguity of "some higher value" is curious. That value may relate to Dunbar's Number, a theory developed by British anthropologist, Robin Dunbar. His research centers on communal groups of primates that evolved to support and care for larger and larger groups as their brains (our brains) expanded in capacity. Dunbar's is the number of people with whom we can maintain a stable relationship — approximately 150.

Some back story

Professor Robin Dunbar of the University of Oxford has published considerable research on anthropology and evolutionary psychology. His work is informed by anthropology, sociology and psychology. Dunbar's Number is a cognitive boundary, one we are likely incapable of breaching. The number is based around two notions; that brain size in primates correlates with the size of the social groups they live among and that these groups in human primates are relative to communal numbers set deep in our evolutionary past. In simpler terms, 150 is about the maximum number of people with whom we can identify with, interact with, care about, and work to protect. Dunbar's Number falls along a logorithmic continuum, beginning with the smallest, most emotionally connected group of five, then expanding outward in multiples of three: 5, 15, 50, 150. The numbers in these concentric circles are affected by multiple variables, including the closeness and size of immediate and extended families, along with the greater cognitive capacity of some individuals to maintain stable relationships with larger than normal group sizes. In other words, folks with more cerebral candlepower can engage with larger groups. Those with lesser cognitive powers, smaller groups.

The number that triggers "compassion collapse" might be different for individuals, but I think it may begin to unravel along the continuum of Dunbar's relatable 150. We can commiserate with 5 to 15 to 150 people because upon those numbers, we can overlay names and faces of people we know: our families, friends and coworkers, the members of our clan. In addition, from an evolutionary perspective, that number is important. We needed to care if bands of our clan were being harmed by raids, disaster, or disease, because our survival depended on the group staying intact. Our brains developed the capacity to care for the entirety of the group but not beyond it. Beyond our ingroup was an outgroup that may have competed with us for food and safety and it served us no practical purpose to feel sad that something awful had happened to them, only to learn the lessons so as to apply them for our own survival, e.g., don't swim with hippos.

Lapses

Imagine losing 10 family members in a house fire. Now instead, lose 10 neighbors, 10 from a nearby town, 10 from Belgium, 10 from Vietnam 10 years ago. One could almost feel the emotion ebbing as the sentence drew to a close.

There are two other important factors which contribute to the softening of our compassion: proximity and time. While enjoying lunch in Santa Fe, we can discuss the death toll in the French revolution with no emotional response but might be nauseated to discuss three children lost in a recent car crash around the corner. Conflict journalists attempt to bridge these geotemporal lapses but have long struggled to ignite compassion in their home audience for far-flung tragedies, Being a witness to carnage is an immense stressor, but the impact diminishes across the airwaves as the kilometers pile up.

A Dunbar Correlation

Where is the inflection point at which people become statistics? Can we find that number? In what way might that inflection point be influenced by the Dunbar 150?

"Yes, the Dunbar number seems relevant here," said Gad Saad, PhD., the evolutionary behavioral scientist from the John Molson School of Business at Concordia University, Montreal, in an email correspondence. Saad also recommended Singer's work.

I also went to the wellspring. I asked Professor Dunbar by email if he thought 150 was a reasonable inflection point for moving from compassion into statistics. He graciously responded, lightly edited for space.

Professor Dunbar's response:

"The short answer is that I have no idea, but what you suggest is perfect sense. . . . One-hundred and fifty is the inflection point between the individuals we can empathize with because we have personal relationships with them and those with whom we don't have personalized relationships. There is, however, also another inflection point at 1,500 (the typical size of tribes in hunter-gatherer societies) which defines the limit set by the number of faces we can put names to. After 1,500, they are all completely anonymous."

I asked Dunbar if he knows of or suspects a neurophysiological aspect to the point where we simply lose the capacity to manage our compassion:

"These limits are underpinned by the size of key bits of the brain (mainly the frontal lobes, but not wholly). There are a number of studies showing this, both across primate species and within humans."

In his literature, Professor Dunbar presents two reasons why his number stands at 150, despite the ubiquity of social networking: the first is time — investing our time in a relationship is limited by the number of hours we have available to us in a given week. The second is our brain capacity measured in primates by our brain volume.

Friendship, kinship and limitations

"We devote around 40 percent of our available social time to our 5 most intimate friends and relations," Dunbar has written, "(the subset of individuals on whom we rely the most) and the remaining 60 percent in progressively decreasing amounts to the other 145."

These brain functions are costly, in terms of time, energy and emotion. Dunbar states, "There is extensive evidence, for example, to suggest that network size has significant effects on health and well-being, including morbidity and mortality, recovery from illness, cognitive function, and even willingness to adopt healthy lifestyles." This suggests that we devote so much energy to our own network that caring about a larger number may be too demanding.

"These differences in functionality may well reflect the role of mentalizing competencies. The optimal group size for a task may depend on the extent to which the group members have to be able to empathize with the beliefs and intentions of other members so as to coordinate closely…" This neocortical-to-community model carries over to compassion for others, whether in or out of our social network. Time constrains all human activity, including time to feel.

As Dunbar writes in The Anatomy of Friendship, "Friendship is the single most important factor influencing our health, well-being, and happiness. Creating and maintaining friendships is, however, extremely costly, in terms of both the time that has to be invested and the cognitive mechanisms that underpin them. Nonetheless, personal social networks exhibit many constancies, notably in their size and their hierarchical structuring." Our mental capacity may be the primary reason we feel less empathy and compassion for larger groups; we simply don't have the cerebral apparatus to manage their plights. "Part of friendship is the act of mentalizing, or mentally envisioning the landscape of another's mind. Cognitively, this process is extraordinarily taxing, and as such, intimate conversations seem to be capped at about four people before they break down and form smaller conversational groups. If the conversation involves speculating about an absent person's mental state (e.g., gossiping), then the cap is three — which is also a number that Shakespeare's plays respect."

We cannot mentalize what is going on in the minds of people in our groups much beyond our inner circle, so it stands to reason we cannot do it for large groups separated from us by geotemporal lapses.

Emotional regulation

In a paper, C. Daryl Cameron and Keith B. Payne state, "Some researchers have suggested that [compassion collapse] happens because emotions are not triggered by aggregates. We provide evidence for an alternative account. People expect the needs of large groups to be potentially overwhelming, and, as a result, they engage in emotion regulation to prevent themselves from experiencing overwhelming levels of emotion. Because groups are more likely than individuals to elicit emotion regulation, people feel less for groups than for individuals."

This argument seems to imply that we have more control over diminishing compassion than not. To say, "people expect the needs of large groups to be potentially overwhelming" suggests we consciously consider what that caring could entail and back away from it, or that we become aware that we are reaching and an endpoint of compassion and begin to purposely shift the framing of the incident from one that is personal to one that is statistical. The authors offer an alternative hypothesis to the notion that emotions are not triggered by aggregates, by attempting to show that we regulate our emotional response as the number of victims becomes perceived to be overwhelming. However, in the real world, for example, large death tolls are not brought to us one victim at a time. We are told, about a devastating event, then react viscerally.

If we don't begin to express our emotions consciously, then the process must be subconscious, and that number could have evolved to where it is now innate.

Gray matter matters

One of Dunbar's most salient points is that brain capacity influences social networks. In his paper, The Social Brain, he writes: "Path analysis suggests that there is a specific causal relationship in which the volume of a key prefrontal cortex subregion (or subregions) determines an individual's mentalizing skills, and these skills in turn determine the size of his or her social network."

It's not only the size of the brain but in fact, mentalizing recruits different regions for ingroup empathy. The Stanford Center for Compassion and Altruism Research and Education published a study of the brain regions activated when showing empathy for strangers in which the authors stated, "Interestingly, in brain imaging studies of mentalizing, participants recruit more dorsal portions of the medial prefrontal cortex (dMPFC; BA 8/9) when mentalizing about strangers, whereas they recruit more ventral regions of the medial prefrontal cortex (BA 10), similar to the MPFC activation reported in the current study, when mentalizing about close others with whom participants experience self-other overlap."⁷

It's possible the region of the brain that activates to help an ingroup member evolved for good reason, survival of the group. Other regions may have begun to expand as those smaller tribal groups expanded into larger societies.

Rabbit holes

There is an eclectic list of reasons why compassion may collapse, irrespective of sheer numbers:

(1) Manner: How the news is presented affects viewer framing. In her book, European Foreign Conflict Reporting: A Comparative Analysis of Public News, Emma Heywood explores how tragedies and war are offered to the viewers, which can elicit greater or lesser compassionate responses. "Techniques, which could raise compassion amongst the viewers, and which prevail on New at Ten, are disregarded, allowing the victims to remain unfamiliar and dissociated from the viewer. This approach does not encourage viewers to engage with the sufferers, rather releases them from any responsibility to participate emotionally. Instead compassion values are sidelined and potential opportunities to dwell on victim coverage are replaced by images of fighting and violence."

(2) Ethnicity. How relatable are the victims? Although it can be argued that people in western countries would feel a lesser degree of compassion for victims of a bombing in Karachi, that doesn't mean people in countries near Pakistan wouldn't feel compassion for the Karachi victims at a level comparable to what westerners might feel about a bombing in Toronto. Distance has a role to play in this dynamic as much as in the sound evolutionary data that demonstrate a need for us to both recognize and empathize with people who look like our communal entity. It's not racism; it's tribalism. We are simply not evolved from massive heterogeneous cultures. As evolving humans, we're still working it all out. It's a survival mechanism that developed over millennia that we now struggle with as we fine tune our trust for others.

In the end

Think of compassion collapse on a grid, with compassion represented in the Y axis and the number of victims running along the X. As the number of victims increases beyond one, our level of compassion is expected to rise. Setting aside other variables that may raise compassion (proximity, familiarity etc.), the level continues to rise until, for some reason, it begins to fall precipitously.

Is it because we've become aware of being overwhelmed or because we have reached max-capacity neuron load? Dunbar's Number seems a reasonable place to look for a tipping point.

Professor Dunbar has referred to the limits of friendship as a "budgeting problem." We simply don't have the time to manage a bigger group of friends. Our compassion for the plight of strangers may drop of at a number equivalent to the number of people with who we can be friends, a number to which we unconsciously relate. Whether or not we solve this intellectual question, it remains a curious fact that the larger a tragedy is, the more likely human faces are to become faceless numbers.