The article should be read as polemic (but referencing the science established under the aegis of the IPCC), and as such both well-written and unusual in the tactics they've chosen.
Twentieth-century scientists saw themselves as the descendants of an empirical
tradition often referred to as positivism – after the nineteenth-century French
philosopher Auguste Comte, who developed the concept of “positive” knowledge
(as in, “absolutely, positively true”) – but the overall philosophy is more accurately known as Baconianism. This philosophy held that through experience, observation, and experiment, one could gather reliable knowledge about the natural world, and that this knowledge would empower its holder.
This much is true: what we can measure of the world accurately & precisely is 'positively' true. The theories we build on top of these measurements, though falsifiable, are within their limits, 'positively' true. Their power lies in how they grasp the totality of data, and more contentiously in what they predict, and much more controversially, in what they reveal about the metaphysical basis of the world.
It is because of this we have the Baconian philosophy - 'one could gather reliable knowledge about the natural world', but the following statement is not really true at all - 'that this knowledge would empower its holder'.
Hannah Arendt was clear about this in her book The Human Condition, written after the Manhatten Project, and the atomic bombing of both Hiroshima & Nagasaki. She said, that it was misguided of physicists to think that they would have any real & direct say in how a technology as powerful as Nuclear Bombs will be used or not. It is subject to politics.
Science empowers the scientist with knowledge, but not to effect change on that basis. They can warn, but their warning may not be heeded. One thinks of the prophetic tradition in the Judeo-Christian world, or even in the Greek world of antiquity where the blind seer Tiresias warned Oedipus who did not heed him.
The statement "Humanities actions change the climate" is in principle provable and maybe even falsifiable.
Unfortunately the climate is not like the exact sciences such as Physics or Chemistry in where one can execute repeatable experiments under strict conditions; nor a science like biology where you have many individuals of a species - there is only one climate. Poppers theory of falsifiability doesn't really hold here.
Probably one of the simplest correlatives that one can make here is with smoking. It was in 1950 that the first scientific evidence was published that showed a link between smoking and lung cancer (though one supposes there was suspicions and anecdotal evidence before that). It's taken 60 years to make it more or less socially unacceptable in the western world; to the point where the major tobacco companies were sued under a class action.
One supposes that a similar trajectory will be followed by climate science.