The issue of climate change, among other issues, is being used to promote unity and one world government. But it doesn't follow that this approach is best to climate change or anything else. We need variation in policies and technologies in order to select the best approach (and not get locked in to a sub-optimal approach).
One world government is bad because it will attract evil elements who use it to place all peoples under their control/taxation/exploitation, with no recourse or escape. All in the name of helping people and fighting for <insert your favourite political cause>.
By analogy, it might seem more efficient if families were to live in communal dormitories instead of their separate houses. In reality it would create stultification and at worst mass suffering when individuals took control over all aspects of other families' lives.
Currently, on climate change this variation is some countries doing nothing, others doing worse than nothing (e.g. encouraging mass deforestation, as in Brazil), and some countries doing a little more than nothing, but saying they are doing enough when compared to those who are doing nothing or worse, and that they can't afford to do more because it would put them at a disadvantage to the others. So this is less about "selecting the best approach" and more a race to the bottom of how little one can do while still pretending to care (or alternatively keep denying that the problem even exists and do nothing).
Problem is that, as I said, the architects of globalism are using this issue. They aren't motivated by the climate or any other of several, rotating concerns. They're motivated by a lust for power/wealth/prestige. You can't achieve difficult objectives unless you are really trying--and they aren't!
However you can ruin the efforts of others by demanding that their work serve a primary political agenda.
One world government is bad because it will attract evil elements who use it to place all peoples under their control/taxation/exploitation, with no recourse or escape. All in the name of helping people and fighting for <insert your favourite political cause>.
By analogy, it might seem more efficient if families were to live in communal dormitories instead of their separate houses. In reality it would create stultification and at worst mass suffering when individuals took control over all aspects of other families' lives.