If the sea rises by half a metre over the next 100 years I think my grandchildren will have plenty of time to adjust. Tonight my daughter and her husband and two children are coming home. Not just home for Christmas, they have done that just about every year in the decade or more they have been away. This time they are coming home for good.
Their children are now 6 and 3. They want them to grow up in their own country.
On Facebook last week, my son-in-law told their friends, "Next week we move home. Not just home to Aotearoa New Zealand but home home, to Tamaki Makaurau Auckland, our turangawaewae. We left that city 13 years ago on a journey that has taken us all over the world — Wellington, New York, Brussels (where Elle was born) and Singapore (Eden was born). Now the time is right to give our little ones the same Kiwi childhood we were so lucky to enjoy."
The kids are already Kiwis. Their eighth floor apartment in Singapore was well equipped with New Zealand's splendid children's books, their drawers were full of All Black outfits. They can count in Maori and Mandarin. Their international school had at least one teacher from New Zealand. Their grandparents took a little bit more of New Zealand to them on every visit.
The family used to also come back in June for a change of weather. And every Christmas the kids played with cousins and children of their parents' friends and came to know the local playgrounds and beaches as well as any native.
Now, as they grow up here, many of their contemporaries will know the world as well as they do. It is remarkable how much young families travel these days.
A survey by the online travel agency Expedia was reported this week to have found one in four New Zealand children has a passport by the age of 2.
If proof is needed that every generation is still better off than the one before, travel provides it. My parents were in their 50s before they saw another country, my wife and I went overseas in our mid-20s after working and saving for a few years.
My daughter and future son-in-law saw France on a university holiday. Rising living standards do not just depend on incomes, good things have got cheaper in economies open to global competition.
My generation called it "OE". We hardly hear that phrase now. "Overseas" is no longer something young people experience in one long working journey before returning to get established. These days they take portable careers around the world and come home well established.
The New Zealand I grew up in was a very insular place.
Even when it discarded economic protection in the 1980s it retained a sense of disadvantage from its scale and distance from big markets, which was the reason we did that OE thing.
I wonder whether the internet generation has the same worries. I wonder if they know how hard it is to ensure New Zealand remains a viable base for trade, travel and all the business that provides a first class living standard.
The new Prime Minister is just a year older than my daughter and son in law. The Finance Minister is not much older.
Their generation is now in power, put there by a superannuitant who distrusts open borders, resents immigration, fears global finance and would like to control the currency.
He has pulled his head in since choosing the Government but I can't help worry for the country they are coming home to.
Christmas is not the time for foreboding though. There's every chance the sun will be shining when the kids are running around our place on Monday. They are coming home to a summer better than any I can remember. It has been hot practically every day since Halloween and the sea is already 8C warmer than usual. A higher water temperature will take longer to cool down, guaranteeing this will be an extended summer.
Undoubtedly it is climate change, this generation's "nuclear moment", according to Jacinda Ardern in the election campaign. I should be worrying about that more than the economy perhaps, but I can't. If the sea rises by half a metre over the next 100 years I think my grandchildren will have plenty of time to adjust. If kauri can grow further south, if pastoral farming gives way to more avocados, olives and better shiraz, would that be so bad?
I must be missing something. I probably need to listen to our members of Jacinda's generation when they get home. They've gone further than me, on good international trajectories in their academic and diplomatic careers.
But more than anything I need to spend more time with those little ones. As every grandparent knows, I'll be able to see through their eyes as they discover New Zealand afresh.