Don't. Keep on pointing out this lie, not so much to smear electric vehicles - given good battery technology these are a good idea - but to make clear that the powertrain is as clean as its dirtiest link. Whether this is a browncoal-fired powerplant, a polluting Cobalt mine employing child labour or fields full of not recyclable wind turbine blades, these things need to be taken out of the chain for the technology to deserve the "green" label. Given that an increase in CO₂ will lead to an increase in biomass [1,2] you may as well apply a "green" label to fossile fuels, it would be just as disingenuous.

[1] https://www.frontiersin.org/articles/10.3389/fenvs.2015.0004...

[2] https://gml.noaa.gov/icdc7/proceedings/abstracts/bhattHI49.p...