full transcript
From the Ted Talk by David Keith: A critical look at geoengineering against climate change
Unscramble the Blue Letters
I'll tell you very quickly how the effect works. There are a lot of fun complexities that I'd love to spned the whole evening on, but I won't. But let's say you have sunlight hittnig some particle and it's unevenly heated. So the side facing the sun is warmer; the side away, cooler. Gas molecules that bounce off the warm side bocune away with some extra velocity because it's warm. And so you see a net force away from the sun. That's called the photophoretic force. There are a bunch of other versions of it that I and some collaborators have thought about how to exploit. And of course, we may be wrong — this hasn't all been peer reviewed, we're in the middle of tnnkhiig about it — but so far, it seems good. But it looks like we could achieve long atmospheric lifetimes — much logenr than before — because they're levitated. We can move things out of the ssaeorptrthe into the meohrpesse, in principle solving the ozone prlobem. I'm sure there will be other problems that arise. Finally, we could make the particles migrate to over the poles, so we could arrange the cltamie erneienging so it really focused on the poles. Which would have minimal bad impacts in the mildde of the planet, where we live, and do the maximum job of what we might need to do, which is cooling the poles in case of planetary emergency, if you like.
Open Cloze
I'll tell you very quickly how the effect works. There are a lot of fun complexities that I'd love to _____ the whole evening on, but I won't. But let's say you have sunlight _______ some particle and it's unevenly heated. So the side facing the sun is warmer; the side away, cooler. Gas molecules that bounce off the warm side ______ away with some extra velocity because it's warm. And so you see a net force away from the sun. That's called the photophoretic force. There are a bunch of other versions of it that I and some collaborators have thought about how to exploit. And of course, we may be wrong — this hasn't all been peer reviewed, we're in the middle of ________ about it — but so far, it seems good. But it looks like we could achieve long atmospheric lifetimes — much ______ than before — because they're levitated. We can move things out of the ____________ into the __________, in principle solving the ozone _______. I'm sure there will be other problems that arise. Finally, we could make the particles migrate to over the poles, so we could arrange the _______ ___________ so it really focused on the poles. Which would have minimal bad impacts in the ______ of the planet, where we live, and do the maximum job of what we might need to do, which is cooling the poles in case of planetary emergency, if you like.
Solution
- bounce
- longer
- mesosphere
- middle
- climate
- engineering
- thinking
- stratosphere
- spend
- hitting
- problem
Original Text
I'll tell you very quickly how the effect works. There are a lot of fun complexities that I'd love to spend the whole evening on, but I won't. But let's say you have sunlight hitting some particle and it's unevenly heated. So the side facing the sun is warmer; the side away, cooler. Gas molecules that bounce off the warm side bounce away with some extra velocity because it's warm. And so you see a net force away from the sun. That's called the photophoretic force. There are a bunch of other versions of it that I and some collaborators have thought about how to exploit. And of course, we may be wrong — this hasn't all been peer reviewed, we're in the middle of thinking about it — but so far, it seems good. But it looks like we could achieve long atmospheric lifetimes — much longer than before — because they're levitated. We can move things out of the stratosphere into the mesosphere, in principle solving the ozone problem. I'm sure there will be other problems that arise. Finally, we could make the particles migrate to over the poles, so we could arrange the climate engineering so it really focused on the poles. Which would have minimal bad impacts in the middle of the planet, where we live, and do the maximum job of what we might need to do, which is cooling the poles in case of planetary emergency, if you like.
Frequently Occurring Word Combinations
ngrams of length 2
collocation |
frequency |
climate change |
4 |
reduce emissions |
3 |
cutting emissions |
3 |
moral hazard |
3 |
red line |
2 |
arctic sea |
2 |
sea ice |
2 |
cheap meaning |
2 |
ozone layer |
2 |
cut emissions |
2 |
national academy |
2 |
climate engineering |
2 |
climate impacts |
2 |
Important Words
- achieve
- arise
- arrange
- atmospheric
- bad
- bounce
- bunch
- called
- case
- climate
- collaborators
- complexities
- cooler
- cooling
- effect
- emergency
- engineering
- evening
- exploit
- extra
- facing
- finally
- focused
- force
- fun
- gas
- good
- heated
- hitting
- impacts
- job
- levitated
- lifetimes
- live
- long
- longer
- lot
- love
- maximum
- mesosphere
- middle
- migrate
- minimal
- molecules
- move
- net
- ozone
- particle
- particles
- peer
- photophoretic
- planet
- planetary
- poles
- principle
- problem
- problems
- quickly
- reviewed
- side
- solving
- spend
- stratosphere
- sun
- sunlight
- thinking
- thought
- unevenly
- velocity
- versions
- warm
- works
- wrong