Climate change costs and benefits

Meant to do a post on this a few weeks ago, but climate change and how we deal with it is not going anywhere, so…

Anyway, really interesting piece from Carolyn Kormann in the New Yorker that asks us to re-think how we look at climate change mitigation policies in terms of costs and benefits:

A modest carbon tax of the sort Nordhaus proposed decades ago—one that was then palatable to conservatives—will therefore no longer bring us anywhere near the Paris Agreement targets. But it’s one of many weapons in the arsenal that policymakers need to employ. “The real challenge is finding ways to reduce emissions and maintain economic growth on the timeline demanded by the nature of climate change,” Kenneth Gillingham, an associate professor of economics at Yale University, told me. But, as much as the costs of climate mitigation will undoubtedly increase, the question is whether the benefits of mitigation exceed those costs. “It’s a straw man—and terrible economics—to just point out the costs while ignoring the benefits,” Burke said. He and two co-authors published a paper in Nature last May that shows that the economic benefits of mitigation are going to be much larger than previously believed. Cooler temperatures would help maintain and grow productivity, and reducing carbon emissions means reducing air pollution—specifically particulate matter, or soot—which brings immediate health benefits. They found that keeping global warming to one and a half degrees Celsius (which is nearly impossible at this point), as opposed to two degrees Celsius, would potentially save more than twenty trillion dollars around the world by the end of the century, and significantly reduce global inequality. Beyond two degrees, they wrote, “we find considerably greater reductions in global economic output.” [emphases mine] If nations met their commitments under the Paris Agreement, the world would still see the average global temperature rise by two and a half to three degrees Celsius, which, according to Burke’s paper, would result in a fifteen-to-twenty-five-per-cent reduction in per capita output by 2100. “To just complain about the costs of this transition and ignore the benefits, as is common in the discussion from this Administration,” Burke said, “is some pretty poor cost-benefit analysis from an Administration that prides itself on economic savvy.”

Of course, there’s lots of uncertainty in all this and this is just one set of estimates.  That said, I do think it makes a fundamental point to be emphasized whenever skeptics argue that it is just too expensive to really do anything about climate change and that is that is almost surely far more expensive to do nothing and cost/benefit-wise we’ll likely come out way ahead by trying to tackle this problem.

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Photo of the day

Love this Atlantic gallery looking back at photos from 1969

A wide view of the Moratorium Day demonstration in Washington, D.C., on October 15, 1969. The Moratorium to End the War in Vietnam was a broad single-day protest calling for the end of U.S. involvement in the Vietnam War. 

AP

Genetically modified foods will kill you!

If you eat so much of them that you become obese and develop really bad cardiovascular health.  Otherwise, you’re probably okay.

So, we’ll stick with a food misconception theme here this morning.  I doubt anybody’s done any good work on diet soda misconceptions (hey, maybe that should be me!), but some very good work on GMO misconceptions and I kind of love the findings (via Jesse Singal).  The headline pretty much nails it:

People Who Are Most Fearful Of Genetically Modified Foods Think They Know The Most About Them, But Actually Know The Least

And some of the details:

There are few subjects where a larger gap exists between public opinion and expert opinion than people’s views on foods, like corn or wheat, that have been genetically manipulated to, for example, increase crop yields or bolster pest-resistance. Experts generally view so-called GM foods as totally safe to consume, while the public is suspicious of them — and this divide is massive. One Pew Research Center survey found that just 37 per cent of the American public believed GM foods are safe to eat, compared with 88 per cent of members of the American Association for the Advancement of Science [emphases mine] (public attitudes are similarly negative in the UK, with a 2014 poll finding that 40 per cent of adults felt the government should not promote GM foods, compared with 22 per cent in favour, and the rest unsure).

Unlike some subjects where this divide between layperson and expert opinion is heavily mediated by politics, such as climate change caused by human activity — in the U.S. and elsewhere, conservatives are far less likely to believe in it than are liberals and climate scientists — the GM-food divide doesn’t really have a political dimension: Liberals, centrists, and conservatives are all about equally likely to have what are, from the point of view of experts, unfounded fears about the safety of GM foods…

This can be seen as a subject-specific version of the Dunning-Kruger effect, or people’s tendency to be ignorant about their own ignorance. The finding held across the samples in different countries…

This can be seen as a subject-specific version of the Dunning-Kruger effect, or people’s tendency to be ignorant about their own ignorance. The finding held across the samples in different countries…

As Fernbach and his colleagues note at the end of their paper, even for less-politicised issues like GM foods, their findings suggest that improving public awareness of basic scientific consequences might be more complex than previously realised, since those holding onto the most severe forms of misinformation are also least likely to seek out more facts or be open to hearing the other side. “This suggests that a prerequisite to changing people’s views through education may be getting them to first appreciate the gaps in their knowledge.” Which is a whole other task — and a very important one.

So, eat up those GM foods while consuming your diet soda :-).

Hydrate with caffeinated diet sodas!

That is, if you like soda.  Don’t take up the habit.  I’m not so motivated-reasoning here (can I use motivated reasoning as a compound verb?) on this issue that I would ever argue against the idea that just plain water is best.  But damn am I sick of hearing from everybody about how the diet soda is going to kill me.  “But chemicals!!”  Anyway, I actually had to put up with hearing somebody going on about the cancer link.  Yeah, yeah, come back to me when I consume half my body weight in artificial sweetener.  Here’s what the national cancer institute says on the matter:

Is there an association between artificial sweeteners and cancer?

Questions about artificial sweeteners and cancer arose when early studies showed that cyclamate in combination with saccharin caused bladder cancer in laboratory animals. However, results from subsequent carcinogenicity studies (studies that examine whether a substance can cause cancer) of these sweeteners have not provided clear evidence of an association with cancer in humans. Similarly, studies of other FDA-approved sweeteners have not demonstrated clear evidence of an association with cancer in humans.

As those who eat lunch with me know, I generally consume massive quantities of Diet Dr Pepper (and Diet Coke if its an okay day and on sad days, the damnable Diet Pepsi).  So, there I am drinking 40 ounces or more of liquid which is 99% or so water and people telling me that I am actually dehydrating myself because of the caffeine.  Oh please!  Maybe drinking 40 ounces of caffeinated is like drinking 38 ounces of non-caffeinated, but the idea that I would have a net loss of water?!  Of course, there’s science on this, too:

RESULTS:

The available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg, equivalent to the amount found in 2-3 cups of coffee or 5-8 cups of tea) results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action.

CONCLUSION:

The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine containing drinks in situations where fluid balance might be compromised.

I know, I know, recent research on elevated stroke risk and older women; possible impact on the microbiome, etc., but people really need to stop treating diet soda like I’m drinking turpentine.  I’ll keep taking my chances here.

(Just a few more) quick hits

Some more good links from lasts week I couldn’t let die:

1) Love this on letting your child have their own inner life.

As my children get older, I’m realizing how profoundly my instincts have been shaped by this culture of constant supervision, which wants to believe that it’s the same thing as intimacy. I still prefer it, over all, to the enormous distance that I sometimes felt as a teen-ager toward my parents. But I want to ask: Who is speaking up, today, for a young person’s right to a private life, to secrets, unshared thoughts, unmonitored conversations and relationships?

2) Really like what Drum has been writing about climate change lately:

I don’t have such a plan in mind, of course, but I do have a few guidelines that I think could help someone win this game:

  • Think international. Yes, yes, the Republican Party is hopeless right now and that makes America a non-player. But you shouldn’t obsess about America anyway. Any plan that’s worth the paper it’s written on will focus on things that are most likely to work all around the world.
  • Focus on getting the biggest bang for the buck. “Biggest bang” is pretty obvious: it just means reducing carbon emissions as much as possible as fast as possible. But “for the buck” means more than just the lowest possible price tag. “Price” should be seen as both dollars and as personal sacrifice. The more sacrifice you ask of people, the bigger the cost. The lower the sacrifice, the better chance you have of getting widespread buy-in.
  • Forget the free market. There’s no profit in addressing climate change. In fact, the profit is almost entirely on the other side. This means that any plausible plan has to include lots of government subsidies: subsidies for solar, subsidies for wind, subsidies for electric cars, subsidies for reforestation, etc. Basically, you should accept that virtually every policy you support will happen only to the extent that the government subsidizes it.
  • Lots of shared R&D. We could address climate change solely with existing technology. The problem is that even with truckloads of subsidies, it would demand more sacrifice than people are likely to accept. That means that we desperately need new and better technology on all fronts as soon as possible. This should be a Manhattan Project kind of thing, and in this case it’s OK to be America-centric. Obviously other countries do scientific research as well, but America does the most. What’s more, a project like this really would motivate other countries to get on board with R&D of their own.

And how will all this be paid for? The obvious answer is a whopping big progressive carbon tax. This would provide plenty of money for all those subsidies and would provide a tailwind for all the other carbon-reduction policies you come up with. However, a whopping tax means a big sacrifice, and that probably dooms it to fail. A carbon tax that starts small but steadily increases is one compromise that might work. A carbon tax that pays for more than just climate change might also reduce opposition.

There are plenty of other possibilities. The main thing is to be rigidly realistic at all times. If you ask too much of people, they won’t support your ideas no matter how great they are. And even if they do, they aren’t likely to respond appropriately to the scale of the problem on their own. I haven’t, after all. Neither have you. But that’s OK: climate change won’t be affected much by personal action anyway. It’s too big. Like a war, it requires action on a governmental scale. Unlike a war, however, it has no human enemy to spur citizens to accept the sacrifice it takes to win. It’s up to us to come up with an alternative. [emphasis mine]

3) Charles Pierce on McCabe, Trump, and supine Republicans:

All weekend, the president*’s defenders pounded away at McCabe’s 60 Minutesinterview as proof of the “deep state” conspiracy to undermine the administration*. On Tuesday, McCabe told Today that he had informed the so-called “Gang of Eight”—the bipartisan congressional intelligence chiefs—that he was launching the investigations and that none of them raised any objections. From Politico:

On Tuesday, McCabe disputed the insinuation made by some of his critics that he had made the decision to investigate Trump on his own, arguing that the decision was not a spurious one. “Opening a case of this nature, not something an FBI director — not something that an acting FBI director would do by yourself, right? This is a recommendation that came to me from my team,” he added. “I reviewed it with our lawyers. I discussed it at length with the deputy attorney general… and I told Congress what we’d done.”

The former FBI deputy director warned that just because investigations had been opened it did not mean the agency had drawn any conclusions about them thus far.But, he argued, “you have to ask yourself, if you believe the president might have obstructed justice for the purpose of ending our investigation into Russia, you have to ask yourself why. Why would any president of the United States not want the FBI to get to the bottom of Russian interference in our election?”

The Gang of Eight is made up of the Democratic and Republican leadership in both houses of Congress, plus the chairman and ranking members of the House and Senate Intelligence Committees. In 2017, at the time McCabe requested the investigation, these would have included Senator Mitch McConnell, Speaker Paul Ryan, Richard Burr, and White House lawn ornament Devin Nunes from the House. According to McCabe, even Nunes didn’t object to the investigation. This is just a bit astounding, considering the supine performance of congressional Republicans once the president* got sworn in.

They all know. That’s the main thing. They all know and they’ve done nothing. Historians one day will fall out of their anti-gravity chairs.

4) This is good, “Stop Using the Word “Collusion”—How to Frame the Critical Question at the Heart of Trump-Russia.”

5) CNN’s hiring of a totally unqualified Republican hack to be a “political editor” is do disappointing.  “Liberal media” my ass.  Margaret Sullivan:

In early 2017, Isgur was summoned to meet with President Trump in the Oval Office, where she needed to pledge her loyalty to be named the Justice Department’s spokeswoman by Attorney General Jeff Sessions.

Now CNN has hired Isgur — who has no journalism experience and once slammed her new employer as the “Clinton News Network” — as a political editor.

The network, under heavy fire for the move, was insisting by Tuesday night that she wouldn’t be directing political coverage, although that surely is what a political editor might be expected to do.

That sounds a lot like damage control.

But why CNN made this move to begin with is the deeper and more troubling question.

It strongly suggests that the network’s big thinkers — including head honcho Jeff Zucker — are aiming for a kind of false fairness: a defensive, both-sides-are-equal kind of political coverage that inevitably fails to serve the voting public.

This approach is not guided by what’s good for citizens, but by a ratings-first effort to position the network in the middle of Fox News Channel on the right and MSNBC on the left…

If you’re trying to deepen understanding, bridge the divide or do excellent journalism, this is one of the last moves you’d make.

6) NYT with a “how self-compassionate are you quiz.”  Very.  Honestly, I am probably too self-compassionate :-).

7) Among things I will never feel guilty for– struggling to use “they” as a personal pronoun for a single person.  Sorry, decades of linguistic use wires the brain pretty hard.  I think Virginia Heffernan needs more self-compassion.  Also, I think person who really don’t want to use he or she need to find an entirely new pronoun.  We already have a they and it means more than one person.  And, yes, I accept that languages evolve in change, but not typically in ways that are almost impossible to organically adapt to.

8) Why the Catholic priesthood needs women.  My views on the role of women in the Catholic Church are an area where keeping an open-mind (and some good impetus from my progressive, feminist mother) allowed me to undergo as dramatic a change of opinion as on anything.

9) Interesting research on how the number of push-ups you can do is more predictive of future heart health than a treadmill test.  The best category was 40+ push-ups before muscle failure.  Much to my dismay, I can get into the 30’s, but not quite 40.

Does economic inequality lead to over-parenting?

Yes!  Says some really cool cross-national comparative research.  Great piece in the Post by Economics professors Matthias Doepke and Fabrizio Zilibotti highlighting their research on the matter.  Really, really interesting.

In many American circles, “helicopter parents” monitor their children’s every move, and outliers who let their kids walk home from the playground on their own risk rebuke by local police. Meanwhile, in Switzerland, even kindergartners walk to schoolwithout adult supervision. And Sweden and Germany offer popular “forest kindergartens,” where children stay outdoors in nearly all weather, playing and exploring with minimal adult guidance. In those countries, unlike in U.S. classrooms, early literacy and numeracy are not part of the curriculum, even in regular preschools; teachers emphasize play and craftsinstead. In China, by contrast, strict parenting is a much-discussed part of national life — and was the subject of a hugely popular television series, “Tiger Mom.”

Discussions of differences like these often focus on culture. China’s Confucian tradition, for instance, emphasizes respect for elders, which some observers suggest could be one influence on authoritarian parenting. But we have found in our research that varying parenting styles among nations are rooted primarily in economics — specifically, economic inequality. The common denominator in countries where intense, achievement-oriented parenting abounds is a large gap between the rich and the poor. Conversely, where inequality is low and governments provide safety nets, a more relaxed, permissive parenting style holds sway. [emphases mine]

That suggests that to reduce the epidemic of hypercompetitive and overinvolved parenting in the United States, simply exhorting people to be more laid back won’t work. The only solution is to attack the problem at the root: by combating inequality…

In the United States, about two-thirds of parents include hard work on the list of top values to instill in children; in Sweden, only about 11 percent of parents place hard work that high. This lines up with differences in economic inequality: In the United States, households in the top 20 percent of the income distribution earn on average almost nine times more than households in the bottom 20 percent. In Sweden, the top quintile earns 4.3 times more than the bottom…

Japan serves as an interesting test for our thesis, since it shares some cultural characteristics with China (both countries are influenced by Buddhist and Confucian traditions), yet it’s more economically egalitarian. In Japan, the economic inequality ratio is higher than in Sweden but lower than in China and the United States. Indeed, Japan’s parenting attitudes, as reflected in the World Values Survey, are closer to those in culturally remote Germany and the Netherlands than to China’s.

Across all postindustrial economies, in fact, we found that the share of parents emphasizing “hard work” lines up remarkably consistently with the degree of economic inequality.

Damn that’s interesting stuff!  I’ll just be over here in America trying to parent Swedish style. Okay, realistically, maybe more like Japanese or Italian style. But no helicopters for me.

(Real) quick hits

1) I’m a big fan of the the big 5 personality inventory.  538 with a nice explanation and a nice version of the quiz.  I still get frustrated by “openness to experience” being a single concepts as in some aspects I am very open to experience and I love culture and learning new things, but this is also the guy who would happily eat pizza for lunch five days a week (and often does).

2) Krugman on Elizabeth Warren’s smart plan for universal child care.  I don’t know if Warren would make the best president, but I’m pretty damn confident she has the best policy ideas.

For millions of Americans with children, life is a constant, desperate balancing act. They must work during the day, either because they’re single parents or because decades of wage stagnation mean that both parents must take jobs to make ends meet. Yet quality child care is unavailable or unaffordable.

And the thing is, it doesn’t have to be this way. Other wealthy countries either have national child care systems or subsidize care to put it in everyone’s reach. It doesn’t even cost all that much. While other advanced countries spend, on average, about three times as much as we do helping families — so much for our vaunted “family values” — it’s still a relatively small part of their budgets. In particular, taking care of children is much cheaper than providing health care and retirement income to seniors, which even America does.

Furthermore, caring for children doesn’t just help them grow up to be productive adults. It also has immediate economic benefits, making it easier for parents to stay in the work force…

For the Warren proposal is the kind of initiative that, if enacted, would change millions of lives for the better, yet could actually happen in the near future.

Among other things, unlike purist visions of replacing private health insurance with “Medicare for all,” providing child care wouldn’t require imposing big new taxes on the middle class. The sums of money involved are small enough that new taxes on great wealth and high incomes, which are desirable on other grounds, could easily raise sufficient revenue.

The logic of the Warren plan is fairly simple (although some commentators are trying to make it sound complex). Child care would be regulated to ensure that basic quality was maintained and subsidized to make it affordable. The size of the subsidy would depend on parents’ incomes: lower-income parents would get free care, higher-income parents would have to pay something, but nobody would have to pay more than 7 percent of income.

Warren’s advisers put the budget cost at $70 billion a year, or around one-third of one percent of G.D.P. That’s not chicken feed, but it’s not that much for something that could transform so many lives…

The bottom line is that Warren’s proposal is impressive: It’s workable, affordable, and would do a huge amount of good.

And while this isn’t a horse-race column — I’m not arguing that Warren necessarily will or even should be the Democratic presidential nominee — the field needs more policy ideas like this: medium-size, medium-priced proposals that could deliver major benefits without requiring a political miracle.

3) Really nice Post piece on just went down with even all the Republicans finally admitting we need a new election for NC-9.

4) I was a little disheartened that my son’s middle school health teacher is actually teaching health myths.  In this case, the eight glasses of water a day myth.  Aaron Carroll took it apart back in 2015.

5) Really enjoyed reading John McWhorter on Smollet and victimhood culture:

6) Just in case you didn’t hear the story of the high school that gave out cheerleading awards like the “big boobie award.”  Just ugh.

7) The thinking-man’s libertarian, Will Wilkinson, with a nice piece, “Don’t Abolish Billionaires:
Abolish bad policy instead.”

The empirical record is quite clear about the general form of national political economy that produces the happiest, healthiest, wealthiest, freest and longest lives. There’s no pithy name for it, so we’ll have to settle for “liberal-democratic welfare-state capitalism.” There’s a “social democratic” version, which is what you get in countries like Sweden, Norway and the Netherlands. And there’s a “neoliberal” (usually English-speaking) version, which is what you get in countries like Canada, New Zealand and the United States.

You may prefer one version over the other, but they’re not all that different. And in comparative terms, they’re all insanely great. The typical citizen of these countries is as well-off as human beings have ever been. These places are the historical pinnacle of policy success.

But guess what? There are billionaires in all of them. Egalitarian Sweden, an object of ardent progressive adoration, has more billionaires per capita than the United States.

8) Ah damn was that Dutch historian taking down Tucker Carlson so awesome.

9) Terrific unanimous Supreme Court decision last week on excessive fines and policing for profit:

The Supreme Court struck an extraordinary blow for criminal justice reform on Wednesday, placing real limitations on policing for profitacross the country. Its unanimous decision for the first time prohibits all 50 states from imposing excessive fines, including the seizure of property, on people accused or convicted of a crime. Rarely does the court hand down a ruling of such constitutional magnitude—and seldom do all nine justices agree to restrict the power that police and prosecutors exert over individuals. The landmark decision represents a broad agreement on the Supreme Court that law enforcement’s legalized thefthas gone too far.

10) A nice explanation of how California’s lawsuit against Trump’s emergency is perfectly written to appeal to conservative Justices.  All we need is a modicum of intellectual honesty (I’m actually optimistic on that matter) and we’re good:

This lawsuit joins a series of others that have already been filed by watchdog groups. While they all argue that there is no actual emergency at the southern border, that is not the gravamen of their complaint. Instead of asking the courts to second-guess Trump’s intent, these challengers ask them to decide whether Trump had authority to act in the first place.

The answer, they assert, is no. The Presentment Clause is straightforward: For a bill to become law, it must pass both houses of Congress, then be presented to the president for approval. Yet Congress never passed a bill authorizing and funding the border wall Trump now demands. It never presented such legislation to the president for his signature. This is the stuff of Civics 101. Whatever powers the National Emergencies Act may grant to the president, a federal statute cannot override the Constitution. The executive cannot use funds Congress did not appropriate. He cannot amend statutes himself to create money for pet projects. Trump asked Congress for a large sum of money to construct a border wall; Congress resoundingly and provably said no. The National Emergencies Act does not give him leeway to contravene Congress’ commands.

These problems ought to be catnip for SCOTUS’ conservative justices—particularly Justice Neil Gorsuch. In his very first dissent on the Supreme Court, Gorsuch extolled the virtues of this pristine constitutional system. “If a statute needs repair,” he wrote, “there’s a constitutionally prescribed way to do it. It’s called legislation.” Gorsuch continued:

To be sure, the demands of bicameralism and presentment are real and the process can be protracted. But the difficulty of making new laws isn’t some bug in the constitutional design: it’s the point of the design, the better to preserve liberty.

A year later, in his rightly celebrated opinion in Sessions v. Dimaya, Gorsuch hammered this same point home again. “Under the Constitution,” he wrote, “the adoption of new laws restricting liberty is supposed to be a hard business, the product of an open and public debate among a large and diverse number of elected representatives.” The courts abdicate their responsibility when they ignore the Constitution’s “division of duties” between the branches of government. These “structural worries” form the bedrock of American constitutional governance, whose ultimate goal is to safeguard “ordered liberty.” These new challenges demonstrate that Trump is circumventing these “structural worries” and harming “ordered liberty” in the process.

11) Sorry, but have no sympathy for Americans who betrayed their country to join the brutal, murderous cult that is ISIS and now want to come home and have all be forgiven.

12) There’s a u-curve for the amount of free time that brings you the most happiness.  Honestly, I suspect that I’d be good with more free time than lots of people, “How Much Leisure Time Do the Happiest People Have? Too little, and people tend to get stressed. Too much, and people tend to feel idle.”

13) Not at all surprising to anyone paying attention and not blinded by right-wing Christian ideology, “Meta-Analysis Over Almost 20 Years Has Declared Its Verdict on Abstinence-Only Sex Ed.”  It doesn’t work.

14) Since the opioid crisis is particularly bad in New Hampshire a lot of people are pushing back against legalizing marijuana.  Because smoking pot leads to opioid addiction.  Oh wait.

15) Loved this story on the new, small tyrannosaurs discovered (by a NC State professor!!):

But at just 170 pounds and six feet long from nose to tail, this new human-size dinosaur was muchsmaller than its more famous relative. Growth rings in the bones, much like those in a tree trunk, showed that the individual was at least seven years old and nearly mature. “It’s certainly not a very young individual of a very large species,” Zanno says. Instead, it was an adult—just a small one.

Zanno named it Moros, after the embodiment of impending doom in Greek mythology. It’s a rather dramatic name for such a diminutive dinosaur, but it’s apt considering the creature’s age. Moros lived 96 million years ago, preceding Tyrannosaurus by a good 30 million years. It was a miniature harbinger of the bone-crunching tyrants to come—impending doom, indeed. And its age and size offer important clues about one of the most dramatic plot twists in the dinosaur story.

During the late Jurassic period, at a time when Asia and North America were connected to each other, the first tyrannosaurs evolved in the former continent before crossing over into the latter. At first they were just one of many groups of small-bodied hunters, all skulking subordinately in the shadow of far bigger predators, such as the allosaurs, a family of toothy, two-legged dinosaurs with dangerous claws. But at some point during the Cretaceous period, the allosaurs died out. The tyrannosaurs quickly usurped them, evolving into apex predators that ruled unchallenged in the northern continents until an asteroid strike (perhaps in combination with volcanic activity) ended their reign.

That switch from allosaurs to tyrannosaurs “was a defining event in dinosaur evolution, but we still don’t know very much about it,” says Steve Brusatte from the University of Edinburgh. “We’re not really sure exactly when it happened, if it happened quickly or was more of a prolonged battle, or if it happened across the northern continents all at once.” …

So what the hell happened to the Allosaurs anyway?!

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