If you get the feeling that debate about climate change policy has been going on for years and years, that's because it has for some.
For millennials, it has been a whole lifetime.
The first report on climate change by a New Zealand government was commissioned in 1988, a year when David Lange was Labour Prime Minister, the first Die Hard movie was in cinemas and All Black Ryan Crotty was born.
It was a 28-page report by the Royal Society of New Zealand titled Climate Change in New Zealand.
The most recent big deal event was the Paris Agreement on climate change.
Much happened in between those two significant events.
Debates have raged within politics about the possible and the necessary. Targets have been set and un-set. Sometimes the big parties have agreed and sometimes they have been hampered by smaller parties.
There have been debates about what position to take at international forums and then debates about how New Zealand should meet the commitments made and what part agriculture should play.
The debate going in the select committee rooms at present over the Zero Carbon Bill directly relates to the Paris Agreement and how New Zealand will play its part.
The Paris Agreement was negotiated in the French winter of 2015 to replace the Kyoto Protocol, the previous global agreement to reduce the emissions of six greenhouse gases.
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Paris followed the failed climate change conference in Copenhagen in 2009 which had been attended reluctantly by the Prime Minister at the time, John Key, on the basis that it always looked like it would flop.
Paris was an incredible event, according to National leader Simon Bridges, who attended as Associate Climate Change Minister.
"These conferences of the parties make you both incredibly cynical and somewhat hopeful that the world is working together on some sort of climate change solution."
He said it was a mixture of high-pressure politics and theatrics (there was a shoe-thumping of a desk a la Nikita Khrushchev) and a carnival-like atmosphere with thousands of people wondering between warehouses on the outskirts of Paris.
"You've got stalls from Greenpeace down to the smallest NGOs and the Amazon Rain Forest Protection Society.
"It's like any multilateral organisation … it's hugely flawed but no one has come up with a better way to do it."
The Paris Agreement on climate change settled on a target of limiting the rise in temperature this century to well below 2 degrees Celsius above pre-industrial levels but with a higher hope to limit it to 1.5 degrees Celsius.
"Paris is generally regarded as a real success," said Bridges "Albeit in truth the hard work is still to come."
Whatever New Zealand's pace on climate change, it has rarely been fast enough for the Green Party, which has long championed the cause of addressing climate change.
Climate Change Minister and Green Party co-leader James Shaw has been relatively patient in a consultative process over his bill, setting up New Zealand's long-term target of zero carbon emissions by 2050, other targets for methane, and a climate change commission to advise on how to get there.
But the Greens were by no means the first parliamentary advocates for action on climate change.
Sir Geoffrey Palmer was Environment Minister in the Fourth Labour Government, which commissioned that report from the Royal Society.
It was the same year the United Nations set up the Intergovernmental Panel on Climate Change, a significant date in the evolution of political responses to climate change.
Before getting his teeth into climate change, Palmer had been working on the Ozone Layer Protection Bill to cut emissions of substances that depleted the ozone.
Coincidentally, the chloroflurocarbons and halons that were being targeted were greenhouse gases and led Palmer to say in his "Greenprint for New Zealand" book at the time that the measures in the ozone bill were "an important first step towards solving the much more complex problem of global warming".
Those were Sir Geoffrey's optimistic days.
"It is a very unfortunate thing that New Zealand hasn't been able to lead on this in the way it should have been able to and I'm very sad about it," he told the Herald this week.
"The real difficulty with climate change issues is that the political reaction to them has been at all times, I think, insufficient to the size of the problem."
If it was not tackled with international action, there was no hope of dealing with it.
"The international action needs to be determined and it needs to be decisive and I am not sure those things will occur."
The economic impact of dealing with climate change are "quite profound", Sir Geoffrey said.
"Transforming the New Zealand economy is an enormously difficult job and the later you start the harder it is."
His successor as Environment Minister in the government that followed Labour was Simon Upton, now the Parliamentary Commissioner for the Environment, who is making a strong contribution to the climate change debate.
Palmer wasn't so happy about the fact that Upton did not maintain Palmer's strategy for dealing with climate change, which was published in August 1990.
The Labour government established the aim of a 20 per cent reduction of 1990 carbon dioxide emissions by 2005 as an interim objective. It commissioned a group known as the New Zealand Climate Change Programme to develop a carbon dioxide reduction strategy based on energy management across all sectors.
The big international initiative of the 1990s was the Kyoto Protocol, debated in Japan, in which countries negotiated their commitments among others.
The big debate of the next decade was whether to introduce a simple tax on carbon or an emissions trading scheme. Labour initially favoured a carbon tax, as did the Greens, but it was not willing to proceed without wider support from United Future and New Zealand First.
Labour's Environment Minister David Parker developed the Emissions Trading Scheme with the support of National. But National diluted it soon after gaining power, arguing that the global financial crisis was not a time to be overly restraining business.
The Emissions Trading Scheme is designed to use carrots and sticks – financial incentives and disincentives – to change polluting behaviour of big emitters. But critics say the New Zealand scheme does not work properly because the government does not put a sinking cap on emissions.
And one of the big debates right now, as it has been for almost 20 years, is the role agriculture should play in reducing greenhouse gas emissions, both within the stated targets in the Zero Carbon Bill and within the Emissions Trading Scheme.
Some of the questions look set to be resolved in the bill in the next few months.
But in an area in which policy has been more accustomed to lurching than developing, any resolution may not necessarily be permanent.
NZ CLIMATE CHANGE POLICY
• 1988 UN establishes the Intergovernmental Panel on Climate Change – New Zealand Labour Govt starts developing policy for climate change co-ordinated by Ministry for the Environment. Labour Govt asks the Royal Society to report on the scientific basis of climate change. "Climate Change in NZ" was published in 1988 a more full report, "New Zealand Climate Change Report 1990' was published in 1989.
• 1990 Govt response strategy sets interim target of 20 per cent reduction of 1990 carbon dioxide emissions by 2005.
• 1990 Labour out, National in.
• 1992 United Nations Framework Convention on Climate Change is signed at the Earth Summit in Rio de Janeiro as a structure for negotiating climate change agreements. The UNFCCC recognises that climate change is a threat, that human impact on climate change can be reduced, and it commits countries to work collectively to address the impacts of climate change – 192 countries .
• 1993 Sept NZ under National Govt ratifies the UN Framework Convention on Climate Change.
• 1994 May - UN Framework Convention on Climate Change comes into force. Govt sets new targets to reduce net emissions to 1990 levels by 2020 and raises prospect of carbon charge.
• 1997 The Kyoto Protocol is agreed in Japan under the UN Framework Convention. Each country negotiated and set its own target for 2008 – 2012, known as the first commitment period. NZ agreed not to exceed 1990 levels of greenhouse gas emissions.
• 1999 National out, Labour-Alliance in.
• 2002 New Zealand ratifies the Kyoto Protocol and passes the Climate Change Response Act which enables emissions to be recorded.
• 2002 Labour back in with support from United Future.
• 2003 A levy on livestock farmers was proposed to part-fund research into reducing agricultural emissions but the levy dubbed the fart-tax was abandoned after protest.
2005 May, Labour outlines details of carbon tax to begin in 2007 apply to all sectors exception agricultural methane and nitrous oxide but it cannot get support from NZ First or United Future.
• 2005 December Labour scraps plans for carbon tax with outcry from Green Party.
• 2005 Labour back in with support from New Zealand First.
• 2008 September Labour passes Emissions Trading Scheme with support from NZ First and the Greens. It sets up a tradeable market for emissions designed to create financial incentives to reduce pollution. Sectors that pollute more than its assigned limit must pay for their pollution and those that come under are rewarded with tradeable units. Credits are also earned through afforestation. Agriculture to be brought into the scheme in January 2013.
• 2008 Labour out, National in with support from Act, United Future and Māori Party.
• 2009 New National Govt amends Emissions Trading Scheme to create a transition period into the scheme to 2102 and effectively halve the costs by allowing two tonnes of carbon dioxide equivalent per New Zealand Unit (two for one) , instead of one tonne. National pushes out inclusion of agricultural sector to 2015.
National says it will reduce emission to 10 per cent to 20 per cent below 1990 levels .
• 2011 National back in with support from Act, United Future and Maori Party.
2012 National amends Emissions Trading Scheme by keeping the two tonnes for one unit indefinitely – it was phased out from 2015.
• 2012 Doha hosts conference to negotiate second commitment period for the Kyoto Protocol from 2013 to 2020 to reduce greenhouse gas emissions collectively to at least 18 per cent below 1990 levels in the eight-year period. New Zealand opts out of the Kyoto Protocol and makes its commitments, along with 90 other countries, under the so-called Convention Track.
• 2013 August National announces target to reduce NZ's emissions to 5 per cent less than 1990 levels by 2020. Takes agriculture out of ETS altogether.
• 2014 National back in with support from Act, United Future and Māori Party.
• 2015 December - Paris Climate Agreement signed in as a successor to the Kyoto Protocol but it does not take effect until 2020. Its target is to keep temperature rises within 2 Degrees Celsius this century, but with a higher hope of keeping it within 1.5 degrees Celsius. It allows each country to set its own goals to reduce greenhouse gas emissions, or Nationally Determined Contributions (NDCs) but requires each country to review its NDC every five years. New Zealand's NDC is to reduce greenhouse gas emissions by 30 per cent below 2005 levels by 2030.
• 2017 National out, Labour in, with support from NZ First and Greens
• 2019 The Labour-led Govt introduces the Climate Change Response (Zero Carbon) Amendment Bill setting a target to reduce net carbon emissions to zero by 2050, to set up a Climate Change Commission to give on advice on how to get there and come up with emission reduction targets every five years. The bill sets up separate targets for gross biogenic methane gas emissions, affecting farmers, requiring a 10 per cent reduction on 2017 levels by 2030 and a 24 per cent to 47 per cent reduction by 2050, a range which is expected to be narrowed at some point, either by the select committee or the Climate Change Commission.
• 2019 Interim Climate change Commission recommends bringing agricultural emissions into the Emissions Trading Scheme in 2025 but paying for only 5 per cent of emissions.
This story is part of the Herald's contribution to Covering Climate Now , an international campaign by more than 170 media organisations to draw attention to the issue of climate change ahead of a United Nations summit on September 23. To read more of our coverage go to nzherald.co.nz/climate