#3: Earth at 2° hotter will be horrific. Now here’s what 4° will look like. | Top 10 2019
Third on the Big Think 2019 countdown reveals this is what the world will be like if we do not act on climate change.
DAVID WALLACE-WELLS: Well, I think when we look outside our windows every day, we see a world that is basically stable, and even if we hear a lot about extreme weather, see horrible news of wildfires and droughts and heat waves that kill people all around the world, we still reorient our emotional expectations for what the world will be like in our own lives. And most of our lives have not been yet all that dramatically disturbed by climate change. But in the decades ahead, I think they will be. There's basically no life on Earth that will be untouched by the force of climate in the decades ahead, and in most cases, that means deformed, damaged, transformed.
I think most scientists would say that the best case scenario is 1.5 degrees Celsius of warming. But personally, I think it'll be practically impossible for us to stay below two degrees without what's called negative emissions technology, which is fanciful tech that has been tested and is successful at a lab scale, but needs to be deployed at global scale to make much of a difference. The UN says that to have any chance of staying below two degrees, we need massive use of this technology, which we don't even know enough to trust. So for me, I orient my best case scenario at two degrees. And unfortunately, that's a level of warming that most scientists describe as the threshold of a catastrophe. Many island nations of the world describe it as genocide. That's how vulnerable they are to especially sea level rise at two degrees. But the impacts wouldn't just affect the island nations of the world. Many of the biggest cities in South Asia and the Middle East would be lethally hot in summer at two degrees, which could happen as soon as 2050. These are cities like Calcutta 5, 10, 12 million people. You wouldn't be able to go outside or certainly work outside without incurring a lethal risk. And that could happen, again, just by 2050, which is one reason why the UN expects that we could have 200 million climate refugees by that same date, 2050. 200 million. They think it's possible that we get as many as one billion, which is as many people as live today in North and South America, combined. I don't think those numbers are realistic. I think they're too high. But even if we get 100 million or 150 million climate refugees, it's important to remember that the Syrian refugee crisis, which totally destabilized European politics, led in its way to Brexit, and has transformed our politics globally through the way it's affected Europe, was the result of just one million Syrian refugees coming to the continent. We're talking about a refugee crisis that is almost certain to be 100 times as large, and it comes at a time when most nations of the world are retreating from our commitments to one another, retreating from our organizations and alliances, retreating from the UN, retreating from the EU, and embracing xenophobia and nativism and nationalism. That's especially concerning when you think about what's ahead, because there are going to be many more people in much more desperate need in the decades ahead. And if we don't welcome them, we'll be committing real moral crimes that from the advantage of today seem unconscionable, but which may become more normal, as we move forward into this new transformed world.
When we talk about worst case scenarios, there are a couple of different factors at play. One is what humans do. This is the most important factor. Will we change course? Will we continue to burn coal? Will we continue to produce fossil fuel emissions? The UN says that the track we're on now, the trajectory we're on now is likely to take us to about 4.3 degrees Celsius of warming by the end of the century if we don't change course. 4.3 degrees would mean $600 trillion in global climate damages. That's double all the wealth that exists in the world today. It would mean parts of the world could be hit by six climate driven natural disasters at once. It would mean more than double the warfare that we see today. And the impacts would be in our economic activity. It would be in flooding and the refugee crisis.
There are so many impacts that we have not really been able to think clearly about, because all of us are so reluctant to consider these horrifying outcomes. But the fact that they are horrifying should not make us turn away. It should make us focus on them more intently. We all have all of these psychological reflexes that make us reluctant to consider horrible possibilities. And for that reason, it's more important for us to take seriously the science, because we need to fight against those impulses to do better planning, to take more aggressive action than we would if we allowed ourselves to slip back into complacency. But there are cases that are worse than 4.3 degrees. There are what are called feedback loops in the climate system that could conceivably accelerate warming beyond what human action does. So there is what's called the albedo effect, which is a little complicated to explain. But sunlight is reflected back into outer space by any surface that's white; that's why when you wear a white shirt, you're cooler than if you wear a black shirt in the summer. The less arctic ice there is, the less reflective white ice there is at the top of the planet. That means more sunlight is being absorbed, which means that more warming would take place. So as arctic ice melts, the planet's ability to reflect solar energy back into space would diminish, and warming would accelerate. There is frozen in the Arctic permafrost a lot of methane, or I should say a lot of carbon, which could be released into the atmosphere as methane if that permafrost melts. Methane is, depending on how you count, at least 30 and perhaps 80 times as powerful a greenhouse gas as carbon dioxide. And there is enough carbon in that permafrost to double the concentration of carbon in the atmosphere that we have today. If that were released, it could accelerate warming by a couple of degrees all on its own. There are many more feedback loops like this.
Just this past week there was a study about cloud formation. If we get to about 1,200 parts per million of carbon, which is much higher than we are today at about 410, but it's conceivable early next century, we would completely disrupt the planet system for cloud formation. And that impact alone, scientists say in this study, would add 8 degrees Celsius of warming to the system. So we'd probably be at already 4 and 1/2 or 5 degrees by then, and we could immediately be brought to 12 and a half or 13 degrees Celsius. And that really would make much of the planet literally uninhabitable, not just the equatorial band, not just the tropics, but there would be places in the mid latitudes that would just be too hot to live. And we have not really begun to think about those possibilities. This is the world that we're entering into now, at just 1.1 degrees, but the whole range of possibilities stretches before us, and even the quite optimistic outcomes are horrifying. Two degrees is genocide, the island nations of the world say. Four degrees is at least twice as bad, depending on how you count. And there are possibilities north of 4 degrees, which are even scarier, because it would mean that the climate system had escaped human control.
- The third most popular video of 2019 presents a frightening truth: The best-case scenario of climate change is that world gets just 2°C hotter, which scientists call the "threshold of catastrophe".
- Why is that the good news? Because if humans don't change course now, the planet is on a trajectory to reach 4°C at the end of this century, which would bring $600 trillion in global climate damages, double the warfare, and a refugee crisis 100x worse than the Syrian exodus.
- David Wallace-Wells explains what would happen at an 8°C and even 13°C increase. These predictions are horrifying, but should not scare us into complacency. "It should make us focus on them more intently," he says.
The Uninhabitable Earth: Life After Warming
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Evolution doesn't clean up after itself very well.
- An evolutionary biologist got people swapping ideas about our lingering vestigia.
- Basically, this is the stuff that served some evolutionary purpose at some point, but now is kind of, well, extra.
- Here are the six traits that inaugurated the fun.
The plica semilunaris<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NjgwMS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY3NDg5NTg1NX0.kdBYMvaEzvCiJjcLEPgnjII_KVtT9RMEwJFuXB68D8Q/img.png?width=980" id="59914" width="429" height="350" data-rm-shortcode-id="b11e4be64c5e1f58bf4417d8548bedc7" data-rm-shortcode-name="rebelmouse-image" />
The human eye in alarming detail. Image source: Henry Gray / Wikimedia commons<p>At the inner corner of our eyes, closest to the nasal ridge, is that little pink thing, which is probably what most of us call it, called the caruncula. Next to it is the plica semilunairs, and it's what's left of a third eyelid that used to — ready for this? — blink horizontally. It's supposed to have offered protection for our eyes, and some birds, reptiles, and fish have such a thing.</p>
Palmaris longus<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NjgwNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzMzQ1NjUwMn0.dVor41tO_NeLkGY9Tx46SwqhSVaA8HZQmQAp532xLxA/img.jpg?width=980" id="879be" width="1920" height="2560" data-rm-shortcode-id="4089a32ea9fbb1a0281db14332583ccd" data-rm-shortcode-name="rebelmouse-image" />
Palmaris longus muscle. Image source: Wikimedia commons<p> We don't have much need these days, at least most of us, to navigate from tree branch to tree branch. Still, about 86 percent of us still have the wrist muscle that used to help us do it. To see if you have it, place the back of you hand on a flat surface and touch your thumb to your pinkie. If you have a muscle that becomes visible in your wrist, that's the palmaris longus. If you don't, consider yourself more evolved (just joking).</p>
Darwin's tubercle<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NjgxMi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0ODUyNjA1MX0.8RuU-OSRf92wQpaPPJtvFreOVvicEwn39_jnbegiUOk/img.jpg?width=980" id="687a0" width="819" height="1072" data-rm-shortcode-id="ff5edf0a698e0681d11efde1d7872958" data-rm-shortcode-name="rebelmouse-image" />
Darwin's tubercle. Image source: Wikimedia commons<p> Yes, maybe the shell of you ear does feel like a dried apricot. Maybe not. But there's a ridge in that swirly structure that's a muscle which allowed us, at one point, to move our ears in the direction of interesting sounds. These days, we just turn our heads, but there it is.</p>
Goosebumps<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NzMxNC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNzEyNTc2Nn0.aVMa5fsKgiabW5vkr7BOvm2pmNKbLJF_50bwvd4aRo4/img.jpg?width=980" id="d8420" width="1440" height="960" data-rm-shortcode-id="8827e55511c8c3aed8c36d21b6541dbd" data-rm-shortcode-name="rebelmouse-image" />
Goosebumps. Photo credit: Tyler Olson via Shutterstock<p>It's not entirely clear what purpose made goosebumps worth retaining evolutionarily, but there are two circumstances in which they appear: fear and cold. For fear, they may have been a way of making body hair stand up so we'd appear larger to predators, much the way a cat's tail puffs up — numerous creatures exaggerate their size when threatened. In the cold, they may have trapped additional heat for warmth.</p>
Tailbone<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NzMxNi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3MzQwMjc3N30.nBGAfc_O9sgyK_lOUo_MHzP1vK-9kJpohLlj9ax1P8s/img.jpg?width=980" id="9a2f6" width="1440" height="1440" data-rm-shortcode-id="4fe28368d2ed6a91a4c928d4254cc02a" data-rm-shortcode-name="rebelmouse-image" />
Image source: Decade3d-anatomy online via Shutterstock<p>Way back, we had tails that probably helped us balance upright, and was useful moving through trees. We still have the stump of one when we're embryos, from 4–6 weeks, and then the body mostly dissolves it during Weeks 6–8. What's left is the coccyx.</p>
The palmar grasp reflex<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NzMyMC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNjY0MDY5NX0.OSwReKLmNZkbAS12-AvRaxgCM7zyukjQUaG4vmhxTtM/img.jpg?width=980" id="8804c" width="1440" height="960" data-rm-shortcode-id="67542ee1c5a85807b0a7e63399e44575" data-rm-shortcode-name="rebelmouse-image" />
Palmar reflex activated! Photo credit: Raul Luna on Flickr<p> You've probably seen how non-human primate babies grab onto their parents' hands to be carried around. We used to do this, too. So still, if you touch your finger to a baby's palm, or if you touch the sole of their foot, the palmar grasp reflex will cause the hand or foot to try and close around your finger.</p>
Other people's suggestions<p>Amir's followers dove right in, offering both cool and questionable additions to her list. </p>
Fangs?<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Lower mouth plate behind your teeth. Some have protruding bone under the skin which is a throw back to large fangs. Almost like an upsidedown Sabre Tooth.</p>— neil crud (@neilcrud66) <a href="https://twitter.com/neilcrud66/status/1085606005000601600?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Hiccups<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Sure: <a href="https://t.co/DjMZB1XidG">https://t.co/DjMZB1XidG</a></p>— Stephen Roughley (@SteBobRoughley) <a href="https://twitter.com/SteBobRoughley/status/1085529239556968448?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Hypnic jerk as you fall asleep<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">What about when you “jump” just as you’re drifting off to sleep, I heard that was a reflex to prevent falling from heights.</p>— Bann face (@thebanns) <a href="https://twitter.com/thebanns/status/1085554171879788545?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script> <p> This thing, often called the "alpha jerk" as you drop into alpha sleep, is properly called the hypnic jerk,. It may actually be a carryover from our arboreal days. The <a href="https://www.livescience.com/39225-why-people-twitch-falling-asleep.html" target="_blank" data-vivaldi-spatnav-clickable="1">hypothesis</a> is that you suddenly jerk awake to avoid falling out of your tree.</p>
Nails screeching on a blackboard response?<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Everyone hate the sound of fingernails on a blackboard. It's _speculated_ that this is a vestigial wiring in our head, because the sound is similar to the shrill warning call of a chimp. <a href="https://t.co/ReyZBy6XNN">https://t.co/ReyZBy6XNN</a></p>— Pet Rock (@eclogiter) <a href="https://twitter.com/eclogiter/status/1085587006258888706?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Ear hair<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Ok what is Hair in the ears for? I think cuz as we get older it filters out the BS.</p>— Sarah21 (@mimix3) <a href="https://twitter.com/mimix3/status/1085684393593561088?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Nervous laughter<blockquote class="twitter-tweet" data-lang="en"><p lang="en" dir="ltr">You may be onto something. Tooth-bearing with the jaw clenched is generally recognized as a signal of submission or non-threatening in primates. Involuntary smiling or laughing in tense situations might have signaled that you weren’t a threat.</p>— Jager Tusk (@JagerTusk) <a href="https://twitter.com/JagerTusk/status/1085316201104912384?ref_src=twsrc%5Etfw">January 15, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Um, yipes.<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Sometimes it feels like my big toe should be on the side of my foot, was that ever a thing?</p>— B033? K@($ (@whimbrel17) <a href="https://twitter.com/whimbrel17/status/1085559016011563009?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Research has shown how important empathy is to relationships, but there are limits to its power.
- Empathy is a useful tool that allows humans (and other species) to connect and form mutually beneficial bonds, but knowing how and when to be empathic is just as important as having empathy.
- Filmmaker Danfung Dennis, Bill Nye, and actor Alan Alda discuss the science of empathy and the ways that the ability can be cultivated and practiced to affect meaningful change, both on a personal and community level.
- But empathy is not a cure all. Paul Bloom explains the psychological differences between empathy and compassion, and how the former can "get in the way" of some of life's crucial relationships.