4 ms·

Isn't it better to meet in a place where one of the people is already located? Then one less person has to fly, and they can use their saved time to work and of

Isn't it better to meet in a place where one of the people is already located? Then one less person has to fly, and they can use their saved time to work and offset the CO2 spent by the additional time traveled by the others.

wolrah 4y ago
> Isn't it better to meet in a place where one of the people is already located? Then one less person has to fly, and they can use their saved time to work and offset the CO2 spent by the additional time traveled by the others. I'm not sure if the tool specifically accounts for that or if the math just ends up working out, but I was testing with various combinations of my family and it always ended up at someone's home airport.
- capableweb 4y ago
  > I'm not sure if the tool specifically accounts for that or if the math just ends up working out, but I was testing with various combinations of my family and it always ended up at someone's home airport. Not sure. But if you put the two locations of Caracas, VE and San Francisco, US, they suggest meeting in Houston, US. Does it make sense? Is it more environmental friendly for two people to meet in the middle rather than having one person staying and the other going there? My gut says the latter should be more environmental friendly.
  - kortilla 4y ago
    Better for one to travel. A disproportionate amount of a flight’s fuel is in takeoff and climb. Meeting in Houston is far worse because you’ve doubled the required takeoff rolls.
    - jamilton 4y ago
      The tool claims to take that into account, it breaks it down in the "show report" button. Liftoff is 3 tons of CO2.
    - gabrielhidasy 4y ago
      Unless it's accounting for no direct flights between Caracas and San Francisco, which would mean either the Caracas person needs to fly to SF connecting in Houston, or both go to Houston in a direct flight, meet there and go back. It's the same 4 takeoffs. (Disclaimer, I have no idea if there are direct flights from Caracas to SF, but from Brazil I always need to stop by in a hub)
      - kortilla 4y ago
        Even with a layover, it’s better for one to do it because it’s one less hotel room, airport transport, etc.
- jameshart 4y ago
  It's certainly not always the case. In planar Euclidean geometry, for any three points, if the triangle formed by those three points has all its angles less than 120 degrees, then the sum of the distances from the three points to certain points inside the triangle will be smaller than the sum of the shortest two sides. Only if one of the angles exceeds 120 degrees will one of the three points always have the shortest total travel distance. The relevant concept is the 'Fermat point', which is the point that minimizes total distance from the vertices of a triangle. In spherical geometry, it gets more complicated, but the same logic applies to spherical triangles that aren't too large. You can definitely find sets of three points on a sphere, such that points inside the triangle are the one which minimizes travel distance.
  - Kwpolska 4y ago
    Does this still hold if you count the flown distance twice, because the meeting participants would probably like to get back home after it ends?
    - winnit 4y ago
      Of course, the lengths are just doubled. If someone travels twice as far to get to someone’s home they also have to travel twice as far back. If the two met in the middle instead there would be four journeys but each would be half as long (2+2=1+1+1+1).
  - wiml 4y ago
    The carbon cost of a flight isn't a linear function of its distance, though — takeoff is much more expensive than cruise, and on long flights there's the cost of hauling the fuel itself, rocket-equation style. (Presumably the data underlying this website accounts for all that.)
    - seabass-labrax 4y ago
      Indeed; furthermore, some air traffic control regions have adopted a direct routing strategy, replacing the conventional routing strategy of published airways. This means that a flight from, say, Prague to Bucharest should be ever so slightly more efficient than the equivalent distance from London to Venice because of the direct routing.
dheera 4y ago
I guess if you're optimizing on the other metrics, yes, but if you're optimizing for CO2 only the best solution may not necessarily be where someone is already located. However, I did try putting in e.g. 10 x Boston, 1 x London, 1 x Paris, and it did in fact suggest Boston as the meeting point. Realistically, it is often also the case that the announced location of a meeting influences who attends it, as compared to travelling for a conference (flights + lodging + meals), the costs are much, much lower for people who already live in that city, who need to only buy the entry ticket. So if you announce a conference in Paris instead of Boston you might expect a bunch of people who already live in Paris to suddenly want to attend. This effect is hard to account for.
bagels 4y ago
If you enter two locations, it picks one of the two as the meeting place.
- jamilton 4y ago
  Not necessarily. San Francisco and New York give me Chicago.
Eric_WVGG 4y ago
Agreed. If > 50% of the attendees are already in a central-ish location, that changes the calculation by quite a lot. Fun and well-designed tool, though.

wolrah 4y ago

> Isn't it better to meet in a place where one of the people is already located? Then one less person has to fly, and they can use their saved time to work and offset the CO2 spent by the additional time traveled by the others. I'm not sure if the tool specifically accounts for that or if the math just ends up working out, but I was testing with various combinations of my family and it always ended up at someone's home airport.

capableweb 4y ago
> I'm not sure if the tool specifically accounts for that or if the math just ends up working out, but I was testing with various combinations of my family and it always ended up at someone's home airport. Not sure. But if you put the two locations of Caracas, VE and San Francisco, US, they suggest meeting in Houston, US. Does it make sense? Is it more environmental friendly for two people to meet in the middle rather than having one person staying and the other going there? My gut says the latter should be more environmental friendly.
- kortilla 4y ago
  Better for one to travel. A disproportionate amount of a flight’s fuel is in takeoff and climb. Meeting in Houston is far worse because you’ve doubled the required takeoff rolls.
  - jamilton 4y ago
    The tool claims to take that into account, it breaks it down in the "show report" button. Liftoff is 3 tons of CO2.
  - gabrielhidasy 4y ago
    Unless it's accounting for no direct flights between Caracas and San Francisco, which would mean either the Caracas person needs to fly to SF connecting in Houston, or both go to Houston in a direct flight, meet there and go back. It's the same 4 takeoffs. (Disclaimer, I have no idea if there are direct flights from Caracas to SF, but from Brazil I always need to stop by in a hub)
    - kortilla 4y ago
      Even with a layover, it’s better for one to do it because it’s one less hotel room, airport transport, etc.
jameshart 4y ago
It's certainly not always the case. In planar Euclidean geometry, for any three points, if the triangle formed by those three points has all its angles less than 120 degrees, then the sum of the distances from the three points to certain points inside the triangle will be smaller than the sum of the shortest two sides. Only if one of the angles exceeds 120 degrees will one of the three points always have the shortest total travel distance. The relevant concept is the 'Fermat point', which is the point that minimizes total distance from the vertices of a triangle. In spherical geometry, it gets more complicated, but the same logic applies to spherical triangles that aren't too large. You can definitely find sets of three points on a sphere, such that points inside the triangle are the one which minimizes travel distance.
- Kwpolska 4y ago
  Does this still hold if you count the flown distance twice, because the meeting participants would probably like to get back home after it ends?
  - winnit 4y ago
    Of course, the lengths are just doubled. If someone travels twice as far to get to someone’s home they also have to travel twice as far back. If the two met in the middle instead there would be four journeys but each would be half as long (2+2=1+1+1+1).
- wiml 4y ago
  The carbon cost of a flight isn't a linear function of its distance, though — takeoff is much more expensive than cruise, and on long flights there's the cost of hauling the fuel itself, rocket-equation style. (Presumably the data underlying this website accounts for all that.)
  - seabass-labrax 4y ago
    Indeed; furthermore, some air traffic control regions have adopted a direct routing strategy, replacing the conventional routing strategy of published airways. This means that a flight from, say, Prague to Bucharest should be ever so slightly more efficient than the equivalent distance from London to Venice because of the direct routing.

dheera 4y ago

I guess if you're optimizing on the other metrics, yes, but if you're optimizing for CO2 only the best solution may not necessarily be where someone is already located. However, I did try putting in e.g. 10 x Boston, 1 x London, 1 x Paris, and it did in fact suggest Boston as the meeting point. Realistically, it is often also the case that the announced location of a meeting influences who attends it, as compared to travelling for a conference (flights + lodging + meals), the costs are much, much lower for people who already live in that city, who need to only buy the entry ticket. So if you announce a conference in Paris instead of Boston you might expect a bunch of people who already live in Paris to suddenly want to attend. This effect is hard to account for.

bagels 4y ago

If you enter two locations, it picks one of the two as the meeting place.

jamilton 4y ago
Not necessarily. San Francisco and New York give me Chicago.

Eric_WVGG 4y ago

Agreed. If > 50% of the attendees are already in a central-ish location, that changes the calculation by quite a lot. Fun and well-designed tool, though.