By "the last temperature change of this rapidity", I assumed the commenter was referring to the end of the Younger Dryas at the end of the last ice age, which is more or less synchronous with a mass extinction in the Americas. The PETM was a remarkable event and a useful example, but as you point out, it was a lot earlier and wasn't as rapid as what we're seeing now.

That's both a bad example and a good one. Many scientists believe those didn't die off due to climate change, but because humans killed them all and ate them. Which means it can't be used as an example of effects of climate change on ecosystems, but it is a good example of how even primitive humans can cause global ecosystem damage.

Look at the Sahara. Look at the Canadian Rockies. Oh shit what happened to your argument?

You are right though, that diversity is higher overall in warmer climates. But *change* in climate is pretty much always bad for diversity, everywhere, as is reducing the number of distinct climate regions.

Ah hah! Denying climate change causes local climate to cool! So if we all wish real hard, and the problem will go away. It's the Tinkerbell Protocol!

They're both pretty full of themselves, but Musk is a pompous engineer at heart whose projects mostly work. Branson is a pompous frat boy at heart whose projects kill people.

WhiteKnightTwo is just an airplane. We've already got plenty of those. Virgin so-called-Galactic has nothing capable of getting anywhere near low earth orbit: even their failed rocket was only suborbital. This "plan" is like planning a trip to Japan, when you've bought a taxi to the airport but no plane ticket.

Hell, your average cell phone user thinks they *are* sat phones.

I'd love to see more competition at the 4 MBps level, but I'm not sure why I need 25 MBps of bandwidth. At 4 MBps, I can stream a couple of 1080p videos simultaneously or download almost any triple-A game in an hour or two.

If I were trying to serve a popular website off my home computer, back up my terabyte hard disk nightly, I might need more, but that would be stupid. If I wanted to stream 5k video, I'd need more, but 5k video is also stupid. For consumer use, there's no way the human eyeball can actually consume data at more than 4 MBps; what am I missing out on by not having what TFA calls "baseline for the full benefits of internet access"?

If you don't want to bother going into space, you can achieve precisely the same effect by staring at a light bulb for a moment.

I said "how computers work *and* how to fix them" because I realize those are two different skills. Most of the kids I work with have neither. No you don't have to know how to build an adder out of NAND gates to be good at computers, but my students are pretty vague on the difference between a file, a program, and a web page.

Everyone talks about how today's young people are computer geniuses, but I'm a college physics professor, and I can tell you that kids coming up from high school are as clueless about tech as their grandparents. They just know how to Twitter and Instagram, but they have no idea how computers or the Internet work.

This isn't new, of course, nobody understands the technology their world is based on. My father and grandfather lived in an era where most people knew how a car worked and how to fix it, but in my generation that's a mystery. I understand how computers work and how to fix them, but the next generation treats them as black boxes. And so on.

This is really a historian problem, not a science problem. India and Pakistan have a long and difficult backstory with regard to nationalist historiography: following the overthrow of the British empire, they quite understandably had a bit of anti-Western sentiment and a re-appreciation of indigenous history and culture. Unfortunately this translated into some pretty jingoistic "we created everything" hypernationalism, which was most prominent in the '60s and '70s, but continues today.

Case in point: I once wrote an essay in college on the science and math knowledge of the Indus Valley civilization circa 1800 BC. One of my sources claimed that these folks invented everything from relativity to calculus to quantum mechanics, but the best bit was an archaeologist who measured the ruins of a circular well, noticed that the ratio of its circumference to its diameter was about 3.1, and argued that this meant the Indus River folks knew the value of pi.

Nobody really needs to be free of malaria and polio either, but it is a pretty nice luxury.

Our goal for the future shouldn't be to get rid of everything we don't need to survive. Our goal should be to see how many of the awesome fruits of modern society we can keep around for the long haul. No, jet aircraft aren't *necessary*, but they make the world a better place in a ton of different ways, and their fossil footprint is small enough that we can afford to keep using them, if we make it a priority. And I think we should.

In our efforts to decarbonize our society, aircraft should be the last to go. There's no renewable technology that's likely to match what a passenger jet can do (try to design a battery-powered Airbus. You won't get far.) Also, the amount of carbon dioxide they emit is pretty minor, relatively speaking. I'm a pretty big global warming doomsayer, but even I want to live in a world where I can fly to the other side of the planet in 24 hours if I really have to.

I already mentioned multiple floors in my comments. If you're imagining something like the Burj Khalifa, imagine ONE THOUSAND of them side by side.
Or maybe you're prefer something wider and flatter, like the U.S. Pentagon building? No problem, just build EIGHT HUNDRED of those stacked on top of each other.

This is the world's largest building by floor area. 430 km^2 would be 400 of them.