Maybe relevant to the conversation, but a letter in Science magazine from April 2019 that supports the youth protests (not this specific one today, but ones in past occurrences) has since been signed by over 3000 scientists:
https://science.sciencemag.org/content/364/6436/139.2
The world's youth have begun to persistently demonstrate for the protection of the climate and other foundations of human well-being. (1, 2). As scientists and scholars who have recently initiated similar letters of support in our countries, we call for our colleagues across all disciplines and from the entire world to support these young climate protesters (3). We declare: Their concerns are justified and supported by the best available science. The current measures for protecting the climate and biosphere are deeply inadequate.
Last paragraph (for quick reading):
The enormous grassroots mobilization (2) of the youth climate movement—including Fridays for Future, School (or Youth) Strike 4 Climate, Youth for (or 4) Climate, and Youth Climate Strike (7)—shows that young people understand the situation. We approve and support their demand for rapid and forceful action. We see it as our social, ethical, and scholarly responsibility to state in no uncertain terms: Only if humanity acts quickly and resolutely can we limit global warming, halt the ongoing mass extinction of animal and plant species, and preserve the natural basis for the food supply and well-being of present and future generations. This is what the young people want to achieve. They deserve our respect and full support.