> For example airplanes emit tons of CO2, but if the same 300 people in a plane drove the same distance it could be much worse.

Technically true, however airplanes provoke a rebound effect. By making travel so efficient and fast, it makes people travel more. If airplanes didn't exist all people would simply travel less, not drive more.

And not to be pedantic, but when the above poster said "or you can buy a video game on Steam rather than driving to a picnic", that discounts the amount of times the game developers had to drive to work to create said game. As well, replacing an old appliance or car isn't a straight-forward net savings, you need to take into account the materials harvested and factories that need to be built to produce those new items.

The average game on Steam sells 32000 copies. It takes some seriously poluting developer to offset the picnic of thousands of people.

Also (pedantic but you started it), the society we currently live in is based around work. So if games weren't being developed it is more likely the developers would still travel to work.

That's only if you cut out games. An overall lifestyle change of much less consumption would slash jobs.

I think you are underestimating how much people travelled before airplanes were a thing. First of all pre airplane there was a lot of sea travel, which was accomplished by burning ludicrous amounts of coal to generate steam power.

And long road trips used to be a cultural pass time. This is why Route 66 is to some extent still such a cultural / historical icon. It used to be that American middle class families loaded into a gas guzzling vehicle to drive cross country for vacation.

I've thought as far as congestion is concerned cheap electric and self driving cars could make things worse. Especially if is as expected the price of EV's drops below the price of gasoline powered cars. Probably not that make effect in the US but in countries like India and China on the other hand.

yes this (traveling and growth) is great. Also, amount of energy consumed historically correlates with quality of life.

Emissions are bad, but technology plus well thought-through policy has a potential to reduce them dramatically while both stimulating growth and energy consumption (nuclear + renewables and storage, electric cars, trains, etc.)

I would travel the same. Just with a car. I do three big trips a year of around 1,600km one way.

There was recently a CCC talk [1] about sustainability of software,... there was mentioned, streaming a video is almost as toxic as driving 20 km forth and back.

For sure, this is super vague, but i guess it's still good to consider all those internet traffic. local internet-caching could be a good solution to keep things more regional...

1: https://media.ccc.de/v/thms-49-ber-die-nachhaltigkeit-von-so...

> Advanced economies have grown their GDPs, but have also reduced their emissions since about 1990.

Isn't there an element of offloading their emissions to the 'less advanced' economies who make all of the new energy efficient nuggets?

Production of traded goods account for about 20% of GHG emissions. So, significant but not decisive.

> Some consumption is good, i.e. replacing and old appliance or a car with a more efficient one

Isn't buying a used (ICE) car better for the environment than a new EV one?

Counterfactual reasoning can be tricky. We do want electric vehicles to be manufactured instead of other kinds of vehicles, and they won't be if nobody buys them. So, maybe you're doing your bit to make sure they're successful, versus less efficient vehicles? If you buy used then you're accepting other people's decisions about which new cars should be successful.

On the other hand, maybe you're thinking the total number of cars to be manufactured should go down, and this will happen if people stop buying them.