The carbon footprint generated by the royal wedding could be equalled by flying return between New Zealand and London 723 times, research suggests.
Landcare Research has estimated how much carbon Will and Kate's wedding will generate, based on the travel of international guests such as Victoria Beckham, local crowd travel, and venue emissions.
It estimates the wedding will emit 6765 tonnes of carbon dioxide equivalents. This is equivalent to the yearly emissions from 1230 households, or 12 times the annual emissions of Buckingham Palace.
Landcare Research carboNZero programme general manager Ann Smith said the analysis had been undertaken as a fun exercise, based on information from articles in the British news media.
It was understood 1900 people were invited to the service at Westminster Abbey, with 650 of these attending the lunchtime reception at Buckingham Palace, and 300 going to the dinner.
For Charles and Diana's wedding, 600,000 people lined the streets – so carbon generated from this assumed crowd travelling on trains and the underground was taken into consideration too.
The energy emissions from venues and hotels were also calculated, alongside carbon from the planned flyover of seven planes.
The New Zealand team also offered tips for reducing carbon emissions, such as encouraging guests to car pool, using locally sourced food, minimising merchandise production, and limiting palace energy use.
Professor Smith agreed it was "too late now" for Prince William to take suggestions on board, but said he appeared to have done a good job of keeping the wedding green.
The countdown to the big event begins in the 6pm news bulletins on TV One and TV3, followed by royal specials of Close Up and Campbell Live at 7pm and then rolling wedding coverage across both networks until 10pm, when the official ceremony begins.
TV One will carry the BBC's official uninterrupted broadcast, and TV3 will stream commercial-free ITV.
The event winds up at 12.45am with the traditional balcony kiss between the bride and groom.
- The Dominion Post