Talk of a National-Greens coalition is laughable at best, treacherous at worst, and overall serves no purpose other than to bolster National's hand at the negotiating table with NZ First.
To even consider it a serious prospect you'd have to completely disregard both the recent campaign along with years of National Party history. The Greens campaigned on saying "a vote for us is a vote for Jacinda Ardern as Prime Minister" and were highly supportive when Ardern said "Climate change is my generation's nuclear-free moment".
Meanwhile in 2001, in protest to government proposals to mitigate agricultural greenhouse gas emissions to meet its obligations under the Kyoto Protocol, Bill English drove a tractor on Parliament's forecourt proudly holding a sexist placard which read "THE MAD COW SHOULDN'T HAVE SIGNED", in reference to Helen Clark's ratification of the Kyoto climate change agreement.
It is for these reasons, (along with National's horrendous track record on dirty rivers, child poverty and inequality, et cetera) that the Greens would struggle to meet their constitutional requirement which demands 75 per cent of the party membership needs to agree to a coalition being formed with National.
Greens should also take heed from the Maori Party's demise, which arguably was due to their association with National, guilty by association if you will.