All around the Western world today, some high school students will be not turning up for classes as part of a "strike" for the climate.
In New Zealand cities they will be leaving classes late morning to assemble in civic centres at noon and staying there the rest of the school day, hearing speeches, music, chanting, waving banners and generally making a lot of noise. All to make a resounding statement that climate change threatens their future.
Their schools have taken a variety of views of their planned action. Some such as the principal of Western Spring College have lent the students their unequivocal support. Others, such as Pakuranga College principal Michael Williams, president of the NZ Secondary Principals Association, have called it a "total waste of time".
Some intend to list the students as truants today, others will record their absence as authorised.
Parents and the public will be similarly divided, many applauding the pupils for their ideals and activism, others wondering why they need to make their statement in school hours. Could they not have planned these rallies for tomorrow? Or at least, could they not have asked their schools for leave to attend. A "strike" seems needlessly antagonistic.
But there is no denying, this way makes a more powerful statement. Those who take part are asserting their determination to do something about the rate of climate change sooner rather than later when their generation is in power. By then it might be too late to avoid the catastrophe climate science predicts.
Action of this kind also means that only concerned students are likely to leave school for the afternoon. Students will not be of one mind on this subject. Some will be not as certain that catastrophe is in store, believing instead in the human capacity for adaptability and technological solutions.
Some will just not like the idea of joining in a public protest. They would have simply had the afternoon off if their school had sanctioned today's action.
This way, there should be no suggestion the students who take action are using it as an excuse to skip school. Those who "strike" deserve to be taken seriously.
They are right that climate change is not been treated with urgency by most governments most of the time. The scale of the problem, expressed as a few degrees of temperature rise over a century, makes it hard to convince many that they need to act now.
The concerned students, though, need to demonstrate their convictions with more than a rally in the civic square. They need to ensure they do not use a car to get there today, or to get to school any day.
They ought to be reducing their personal carbon footprint in any way they can. Likewise any teachers who are encouraging them to take this action today should not be in the habit of driving a car to school.
Idealism and passion are fine impulses but unless they are applied to real life they are ultimately of little value. Students in the senior years of secondary school are just discovering the problems of the world and their unbounded belief in their capacity to fix them. Take heart from them, they are right.