Ahead of the 2015 UN climate change conference in Paris (COP21), the Herald's science reporter Jamie Morton is talking to a range of experts on climate-related issues.
Here he talks to Victoria University's Associate Professor Ralph Chapman, author of the new book Time of Useful Consciousness: Acting Urgently on Climate Change.
On New Zealand's new target of reducing its greenhouse gas emissions by 30 per cent from 2005 levels and 11 per cent from 1990 levels by 2030: this has been criticised by some quarters as "weak" and only a little stronger than the previous target for 2020. Dr Adrian Macey described it as "the minimum credible target", particularly as New Zealand had already put on the table a conditional target of 10-20 per cent below 1990 by 2020, and already had its unconditional five per cent below 1990 by 2020 target. What is your view of our target? You've pointed out that biting the bullet now is much better for our economy than to wait the "day of evil" later?
A. A target (Intended Nationally Determined Contribution or INDC) of minus 11 per cent by 2030 is inadequate.
The whole point of New Zealand making a commitment in international negotiations is to "do the right thing" and encourage others to do the right thing.
It is not the physical difference in emissions that New Zealand makes which matters, but the persuasion, the "soft power" that New Zealand can exercise.
By refusing to show significant leadership, at present, New Zealand weakens the negotiations and undermines its own reputation.
New Zealand's INDC is also ethically indefensible, considering New Zealand's comparative prosperity, and the urgent need to act for the sake of future generations, not to mention New Zealand's capacity to further develop renewable electricity, cut transport emissions, and reduce agricultural greenhouse gases (GHGs).
The costs involved in this adjustment process is an investment in a robust future economy, the sort of investment that can be seen in progressive countries such as those in Scandinavia and northern Europe, for example, Sweden, Denmark and Germany.
It's also notable that a great many New Zealanders strongly believe New Zealand needs to act positively and decisively in the international negotiations.
For example, over two thirds of the 11,000 people who made a submission on New Zealand's target for 2030 thought New Zealand should commit to reducing emissions by 40 per cent or more (relative to 1990 levels).
The vast majority (99 per cent) of those who specified a target level recommended that New Zealand take an ambitious target of 40 per cent below 1990 by 2030 or zero carbon by 2050.
I disagree with Dr Adrian Macey in his view that New Zealand's target is "the minimum credible target".
This is a hasty judgement reminiscent of the diplomatic compromise that has led to the world being in the invidious position it is currently in - on a track for well over 2C of global warming, and potentially unmanageable, catastrophic climate change. Lord Nicholas Stern has called this trajectory "reckless".
This is what diplomatic compromise has become. New Zealand can and should do better than this.
Experts at the Royal Society of New Zealand consider a target of 40 per cent by 2030 (relative to 1990 levels) achievable and desirable for New Zealand.
Given criticism of the inefficiency of carbon trading systems, is it somewhat a gamble that we and other nations should be basing emissions reductions goals off them?
A. New Zealand's emission trading system is not inherently inefficient, but it is flawed by its complexity and non-transparency, by rules that enable an oversupply of units on the supply side, and by insufficient demand for units by emitters on the demand side (for example, the requirement that only one unit need be surrendered for every two tonnes of emissions).
New Zealand could easily strengthen its ETS or better still, switch to a more transparent carbon tax.
But there is currently no government will to do so: the ETS reflects a lack of ambition.
Moreover, the minister and ministries are very opaque about New Zealand's intentions with regard to use of stockpiled units (such as ERUs) and how New Zealand might use carried-over units to meet its 2030 target.
Using cheaply purchased units from the past to meet 2030 goals (and thus justify New Zealand's laxity in cutting gross emissions) has an unethical aspect to it, when the international community is trying hard to tighten down the global emissions "balloon".
At Paris, what do you expect our negotiating team will be doing each day? What are the self-interest "wins" you think New Zealand will be looking for?
A. Ideally, the New Zealand team should be explaining its ambitious commitment to other nations, and argue for greater ambition in country commitments consistent with warming being held below 2C.
New Zealand has some positive things to say about research into agricultural GHG abatement, and getting rid of fossil fuel subsidies.
And there are also rules around forestry which New Zealand can legitimately argue are both in New Zealand's interests, and have environmental integrity.
But also, in reality, New Zealand will be on the back foot, trying to explain and defend New Zealand's weak 2030 stance.
Unfortunately, the New Zealand team may also be briefed to find ways in which New Zealand can sidle out of its global commitment by, for example, arguing for rules that enable use of stockpiled cheap units.
Are there any particular areas where you see New Zealand and New Zealand-led policy making any meaningful difference at COP21?
A. Sadly probably not: it seems unlikely New Zealand will make any real difference at COP21 given the government's current INDC stance.
New Zealand has been trying to claim some credit for the shape of the overall agreement, but this is unpersuasive.
The shape of the overall negotiations is essentially set by how far the great powers are prepared to go in terms of commitments.
As noted above, In terms of overall approach, the COP21 parties are likely to reluctantly accept that insisting on a Paris agreement with legally binding commitments is not realistic at present, given the preferred approach of the US and China.
However, this does not detract from the importance of "ambition" in the target New Zealand commits to, and builds off.
New Zealand should be looking to increase its ambition over the inadequate levels the government has so far set out in its INDC.
In terms of the big picture: who do you see as the big players, why, and how much depends on them to come away with a robust agreement? Can we expect to see competing blocks or alliances of nations form?
A. China, the US, India, and Europe, and arguably Brazil and South Africa, are the biggest players, by courtesy of both economic heft and emissions.
China's and India's emissions have been growing fastest, despite successful efforts by China to reduce carbon intensity.
All these parties need to be part of a robust agreement.
There are always negotiating blocs at COPs, but these need not be obstructive, and small nations of sound repute can make a difference at the margins.
New Zealand is largely insignificant against these big players, and can only make a difference by demonstrating positive commitment to be constructive and ambitious in its plans to reduce emissions.
Climate Change Issues Minister Tim Groser said that if mitigation can't be broadened outside Annex 1 countries (developed countries) to developing nations, then developed nations are "wasting their time" with their own climate change efforts. Do you agree?
A. It is true that all nations need to be involved and be ambitious.
But Minister Groser has often painted a rather misleading picture of what developed and developing countries are doing.
China in particular has done a great deal to limit its emissions, and while its total emissions have grown with an expanding economy, its emissions per person (around 9 tonnes in 2014 ) remain less than New Zealand's.
China realises that the morbidity and mortality costs of its air pollution (associated with its carbon emissions) are huge and need to be cut.
One credible estimate is that these costs were around 10-13 per cent of China's GDP in 2010.
We can expect China to be making a large and increasing effort to cut emissions in future. India's stance is less clear.
What influence on commitment-setting has there been from expected advances in future technology that would significantly reduce emissions? Has there been an over-reliance from many nations on waiting for this technology to eventuate? Is it irresponsible to do so?
A. Expectations of technological advances in energy are central to cutting emissions, and all countries will be building such expectations into their INDC targets.
In the past, some international organisations such as the International Energy Agency were too conservative about the uptake of renewable energy technologies.
Of course, this is partly influenced by government support, as well as private sector investment decisions, and sometimes that support is not forthcoming.
But the lessons of the past also strongly suggest that the private sector will not act fast enough without strong and consistent policy support from government; support, for example, which sets favourable "framework conditions" for investment and innovation. This is what enlightened business leaders consistently ask for.
At the same time, there has probably been an over-reliance on technology relative to policy and behaviour change.
For example, a lot can be done over time to cut urban transport emissions by encouraging public and active transport, such as walking and cycling - with many cobenefits - but for various reasons governments have underplayed the potential of such changes.
A factor here is that there is less money to be made through such behavioural changes (compared with new technologies) by the large companies which drive private sector investment and markedly influence the policies of governments.
Generally, what do you anticipate will be the biggest stumbling blocks at Paris to limiting temperature rise to 2C this century? From attending previous conferences, are you at all cynical about getting a good outcome?
A. The biggest barrier to a good outcome from Paris is that political leaders do not see meaningful action as sufficiently supported by their domestic political constituencies and/or their funders.
Most countries at the talks are not real democracies and governments are not responding to real and high levels of public concern about climate change.
Even the governments of the democracies such as the US and New Zealand tend to respond more to the views of influential corporates and political party funders rather than overall public opinion, which favours meaningful mitigation action now.
What we can reasonably expect from Paris is a commitment to some sort of agreement with legal force, but not an agreement with legally binding ambitious targets.
We can also expect years more of negotiations about the detailed rules.
I will personally be surprised if world leaders agree to credibly raise their "ambition" sufficiently to keep warming within 2C; I will be surprised if Paris can get to the point where the future of our children and grandchildren is not severely threatened by unmanageable climate change.
Much has been made of what this conference means for the fate of the planet. Is this really our last chance to achieve a 2C limit before it's too late? Or, as Mr Groser has also pointed out previously, is it a mistake to view mitigation efforts solely against UNFCCC negotiations like Paris?
A. There is always another chance to do a little more later, and to take action outside the ambit of the COP negotiations.
But we are in a "time of useful consciousness" - the global oxygen is running out.
So essentially, yes, time is very short to avoid catastrophic climate change, and Paris is our last big chance.
The physics of the climate and the momentum of the world economy are now in slow motion collision.
In this collision of an immovable system (the climate) and an unstoppable object (the global economy), the economy will come off worse.
Nature does not negotiate, even if parts of it suffer.
In particular, the poor, those in developing countries, and vulnerable species are almost certain to be drastically affected.
*Jamie Morton will be travelling to Paris with support of the NZ Science Media Centre and the Morgan Foundation.