Commodity Fetishism is the idea that under capitalism (at least) the understanding of where and how commodities are produced is severed. We relate to commodities not as things that have a certain quantifiable amount of labour time embodied in them (that someone in South America spent some time mining this ore that was then processed by a facility in Mexico that was then shipped by a team of people at a dock to China where it was further processed by another team of people into a component part of a computer chip for example), but instead as ‘fetishes’, magical idols that simply appear before us that we want for their use-value, but do not think about why it costs what it costs to purchase.
Its link to the climate crisis is that if we’re overwhelmingly severed from where and how our various commodities we consume to live a nice life are produced (in the global North especially), then we’re less likely to get upset, panic or fight-back for the fact that this bit of fruit or that phone took the rape and destruction of some town in Africa or Central America, and that the workers who had a hand in producing those things get paid pennies on the dollar of what it cost us. If we can continue life just consuming commodities without worry or care, then we can walk straight into a climate crisis orchestrated by the capitalist class. The class who are making the active decision to destroy the planet in pursuit of profit, and the active decision to ruin and crush the working classes of the Global South in particular.
EDIT: I should be a little more explicit in my original point on Commodity Fetishism too. I intimated it via the example I gave, but more than just not understanding a commodity as a embodiment of a given amount of labour time, Marx talks about the commodity as a collection of social relations that are obscured under capitalism.
which is commodity fetishism yes