By this he means being sceptical of consensus science, i.e. Darwinian evolution and human-induced climate change.
It seems that most of the marchers are leaning left politically. Some of them are probably worried about the war on science,which, as we know, is another illustration of Orwellian newspeak.
We should not forget that while we have a mandate to care for Earth, we should certainly not worship it – that would be idolatry.