> Climate and environmental concern were dismissed and attacked for decades.
Part of the reason is that the "green" movement has a long history of promoting de-industrialization and generally opposing human flourishing, using "nature" as a type of proxy for this anti-human, anti-development sentiment. Some examples:
* rigid opposition to nuclear power, which continues until the present. We could have moved completely off fossil fuels for electricity production if it were not for the green movement.
* the "environmental" regulations pushed through by the green movement were written with the aim of making development more expensive, resulting in the high price of housing as developers are sued into oblivion in disputations over environmental impact reports.
* the green movement is responsible for our disastrous forest management practices, resulting in thousands of deaths and massive ecological destruction by making it prohibitively expensive to harvest timber from federal lands. See, e.g. https://www.sacbee.com/news/california/fires/article25495772...
* prominent leaders in the green movement have gone on record wishing for mass culling of humanity in order to "save the planet". The most notorious example would be Prince Phillip, fantasizing that he would be reincarnated as a virus to wipe out millions of people in order to help the environment. See, e.g. https://www.scmp.com/magazines/style/news-trends/article/308...
* Absurd crusades such as trying to ban plastic straws, plastic grocery bags, or promoting wasteful recycling programs that are not backed by any rational basis and cause more harm than good.
* Opposition to modern agricultural practices such as use of fertilizer, GMO crops, etc, that allow billions of people to eat in the name of a kind of unscientific primitive romanticism.
* The methods of various "pro environment" groups involving tactics such as domestic terrorism (including murder) to blocking highways as privileged activists lie down in public spaces and sob to "save the planet" turn off a lot of people and cause them to discount what environmentalists have to say.
> Sure, extreme claims will hurt credibility when they don’t pan out.
This has already happened. There really doesn't seem to be much in the way of quality control when it comes to wild claims being made, which leads people to discount all the claims.