Exactly WW2. Kids are taken off school for trips with often dubious educational value, like going to Alton Towers, etc. Many parents take kids off school for the most dubious of reasons- and many take them off to go on cheaper holidays.
What concrete aim? Awareness- and awareness that result into actions in everyday life. Young people who think about their footprint- take the train instead of having own car, go on holiday using night trains (very popular and growing in Europe now), start businesses where everything sold is done loose, with refill packs, refill bottles, fresh local fruit and veg and produce. Solid shampoos and soaps, to stop plastic bottles- powder for washing machine and conditioner made with natural products for refill.
Young people I know get stuck in, get the local politicians and Maires involved - and persuade better practices at council level - put pressure on schools to provide good alternatives for cleaning, food, lighting.... and the list goes on. They are active on a day to day basis. They influence their parents too, ensure changes are made in the household. One of my students refused to go on a long week-end to Portugal recently- and told her parents why. Flying is not necessarily a total NO- but if you do, make sure it is for a decent duration- not for 3 days. And she said, if for a decent duration- she would go by night train anyhow. Putting pressure on our Nationalised train services and others in Europe- to ensure night trains are available and affordable. And on, and on. They think, they research, they plan, they get together and work together, they seek the help of experts, they get stuck in - they do it. Amazing kids.