The response of Government Ministers to rural concerns about forestry policy is polarising the debate. Describing rural perspectives as ‘fiction’, and upset rural protesters as ‘rednecks’, is counter-productive.
The combination of the Zero Carbon Act and forthcoming Emission Trading Scheme legislation will transform the New Zealand landscape. The Government has done a poor job of educating New Zealanders as to what it will mean. The Government is now on the defensive.
In this article, the focus is on multi-rotation production forestry. The associated story of permanent forests must wait for another article.
The starting point is that New Zealand has a policy goal of zero net carbon emissions by 2050. That means, among other things, that either New Zealand has to find new energy sources to replace fossil fuels, or else it has to offset those emission in other ways. The offsetting has to start right now.
There are only two ways to offset emissions. One way is to sequester carbon in trees here in New Zealand. The second is to buy emission rights from overseas people who grow the trees overseas.
This second way is an avoidance strategy, whereby New Zealanders pay others to carry the burden. It only works in a world where there are lots of wealthy people in one part of the world and lots of poor people elsewhere.
Both New Zealand and Australia have played this game in the past. Unfortunately, New Zealand did it with cheap and largely fraudulent emission units from the Ukraine.
Both New Zealand and Australia plan to play the overseas purchasing strategy again, although this time hopefully with more integrity. However, there is not much virtue signalling or salving of consciences by these actions. It cannot be the main game.
To cut to the chase, the new zero-carbon legislation means that New Zealanders will need to totally change their lifestyles, together with planting a huge number of trees in New Zealand over the next thirty years.
To put things into perspective, the current wall of wood coming up for harvest in the next ten years is about 650,000 hectares. This will all need to be replanted, but these replanted forests will not earn carbon credits. It is only new forests on lands not recently in forests that earn carbon credits.
New Zealand’s short to medium term forest policy is encapsulated in Government messaging within the Billion Trees Program. Assuming a planting rate of 1000 trees per hectare, which is typical, then replanted forests will take up most of the Billion Trees Program. It bears repeating that these replanted forests will not earn carbon credits.
Extending the thinking out to 2050, by then almost all of the 1.73 million hectares of existing plantation forest will have been harvested. That too will need replacement with another rotation of trees on the same land just to avoid new carbon liabilities.
The proposed new emission-trading scheme, with its focus on new multi-rotation forestry converted from farmland, will provide forest owners with first-rotation credits based on the average sequestered carbon over multiple rotations. For new forestry based on radiata pine and 28-year rotations, forest-owners will claim credits for the first 17 years of the first rotation.
To state that as explicitly as I can: the carbon benefits relate to long-term accumulated environmental benefits over many rotations, but the total cash benefits are paid out in the first 17 years of the first rotation.
These credits are expected to total about 340 tonnes per hectare of carbon-dioxide equivalent. At current prices of around $25 per tonne, these will be worth around $8500 over 17 years.
However, the smart-money people can see potential for this carbon price, really a carbon-dioxide price, to rise to at least $75 per tonne but perhaps $100 or even $200.
Given a price of $100 per tonne, then a hectare of farmland converted to forestry would earn $34,000 over the next 17 years from carbon trading.
This raises the question as to how much farmland will be converted to forestry. It’s a multibillion-dollar question.
Let’s take a hypothetical figure of 100,000 hectares per year. After 10 years we would have one million hectares of new forests and these would be trucking along earning about 20 million tonnes of carbon credits each year. This would make a sizable dent in our overall net emissions, but would not get us anywhere near zero net emissions.
To put things in perspective, New Zealand’s gross emissions of carbon-dioxide equivalence are around 80 million tonnes per annum. About half of this is long-lived carbon dioxide itself. The remainder is based on equivalence calculations for methane and nitrous oxide.
From a national perspective, one of the problems with 28-year rotation radiate pine is that these trees will only earn credits for 17 years. For the 11 years from year-18 to year-28 the trees are still growing, but neither earning new credits nor incurring new liabilities. So, after 17 years we have to plant more new forests on additional farmland just to keep up the existing flow of credits needed for elsewhere in the economy. It requires running fast to stand still.
Once 28 years have passed, then if the trees are harvested, there will be a liability attached to the land of around 340 tonnes of carbon-dioxide equivalence. To avoid payment of the liability, the land must be replanted in another rotation of forestry. But I emphasise this replanted forest, being second rotation, earns no further credits.
Hence, if we are to move to anywhere near a zero-carbon lifestyle, and unless we can totally eliminate use of fossil fuels, then the forests must continue marching across the landscape, like the mythical triffids of the John Wyndham classic.
So, is there a counter argument as to why the above scenario is alarmist?
The counter argument can only be that new technologies will come to the rescue. Supposedly, we will rely on solar, wind and geothermal, combined with new battery technology, to transform our economy. At that point the march across the landscape can stop.
Actually, the scenario that I have drawn above has already allowed for these technologies coming substantially to the rescue. Without them, the march of the pine trees across the landscape will need to be much greater than 100,000 hectares per year.
Even with policies that are well thought out, there are always prospects of unintended consequences. With carbon trading, there will be substantial windfall gains for people who own non-dairy pastoral land and sell it for forestry. We are seeing that already.
The reason I exclude dairy-land is that dairy economics are sufficiently strong that dairy-land values will provide a buttress against forestry. The forestry will go predominantly on sheep and beef land, although there will be exceptions.
Right now, when non-dairy pastoral land comes on the market there are multiple forestry buyers competing for it. This is particularly the case for land within 70km of a port. The likelihood is that competition for this land can only increase.
In previous articles, I have focused on the role of international investors because they have the scale and financial power to make big decisions quickly with implications that become irrevocable. However, the landscape transformation issue goes well beyond international investors.
If there is a key difference between ‘50 Shades of Green’ folk and the Government, it is that ‘50 Shades’ is looking forward while the Government is relying on rear-mirror statistics.
Right now, the Government has a tiger by the tail.
Posts from Keith Woodford 
You missed one vital point, forestry even without the carbon sequestration is more profitable than farming to the extend of 2 or 3 times more profitable. Our replanted forests, not particularly well located forecast 8% IRR using 12 quarter log prices. Farmers rely on subsidies ie no capital gains tax to give them 6.25% annual capital gain tax free in their land (LINZ figures not mine), as well farmers rely on the New Zealand taxpaper to subsidise their NZU emissions. New Zealand would have the world average of about 8 tonne emissions per person per year if it wasn’t for farming which lifts that figure to 15 tonne per person per year. No forester would ever claim that planting forestry does any more than buy us all time. 50SOG seem to be a privileged group (heavily influended by climate change denial), who want to retain their status and haveeveryone else bear the costs. New Zealand sheep numbers have dropped from 70 million to 27 mil. At 10 su per ha (only that high on the good hills) then 4 million ha have been changed from sheep farming by farmers, noone else, some perhaps 1 mill ha has gone to dairying, the rest is farmers wisely changing land use to more profitable ventures. In the 80’s a 10,000 SU farm had at least 3.5 and robably more like 4 to 4.5 permanent staff, now they have two permanents for 10,000 SU. The depopulation of rural areas has been carried out by farmers, every 300 ha farm has one empty shepherds house or accomodation. Thats where rural depopulation came from, not from forestry.
Cheers Roger Dickie
Thanks Roger,
I am pleased to receive your comment.
I would be pleased to receive more detail on your replanted forests and those 8% IRR calculations.
KeithW
Hello I would like to add a bit more to my response relative to the nonsensical claims that 50SOG are making.
As a long standing but recently exited sheep farming I sympathise with the issues facing farming in the hill country. Agri business including forestry has a lot of common ground. We live in a world of government by opinion poll and all of us rural land users should be standing together. The pity is that FOA, Fed Farmers, Fonterra etc are totally out of touch with responding to public comments and criticism, they seem to think a few TV ads will make the difference. Some of the issues that should be worrying farmers more than a small amount of forest planting are issues of efficiency of production. In 28 years our forests produce 400 tonne per ha of sawn lumber (800 tonne of logs), ie 14 tonne of sawn lumber per ha per year. A productive hill country sheep and beef farm produces around 200 kg sheep carcass meat and 80 kg of beef meat per ha per year ie les than 300 kg of product (and the bone is still in that) per ha per year. Chicken farming of course is about 7 to 9 times more efficient in its use of energy. In response to the ascinine claim that “you can’t eat wood” I am not sure if I have ever seen a house built out of lamb chops or wool.
Employment and labour. On our highly productive hill country farm we spent around $600 per ha every year, thats less than $17,000 per ha in 28 years. On our recently completed forest harvests we spend more than $70,000 per ha over 28 years. Thats four times farming and bears out the independent surveys carried out in Gisborne Wairoa area not that long ago. The fact that a lot of the money is spent in the rural towns and provinces is inconsequential, they are still people and the multiplier affect applies to all money spent on the land.
The environment. Farmers need streams etc for stock water, that is understood, but in so doing they have cattle walking in and out of those streams, defeacating e coli) and causing massive silt incursion into the streams. Top dressing planes spread fertiliser indiscriminately accross their farms including all waterways and nutrient run off contaminates all waterways after every rainfall. They (the farmers) have issues in this modern day climate and environmentally aware world–I am not quite sure how they can economically address those issues. In the meantime foresters apply no fertiliser or chemicals and some of the best trout fishing streams in New Zealand flow out of our plantation forests.
The 1 billion tree programme is a political sham of course. of the 100 million trees planted each of the ten years, 60 million are just foresters replanting their forests as normal course of business., noting to do with government at all For the other 40 million each year, (40,000 ha) I am not sure where that is coming from. Commercial foresters like ourselves get not one cent of subsidy, for new planitngs. everyone said we did so we thought we would test the market . Of course we were declined, exactly as we knew. There are subsidies avaialble to councils, and farmers and other organisations for smaller areas of planting. I don’t have the facts at this time but I think there are 300 to 400 applications for those subsidies, presumably mainly from farmers planting the odd paddock.
Regards Roger
Roger, thanks for the enlightened comments and actually putting numbers on your comparisons. It’s the first I’ve seen of these financial comparisons.
Can I say though that I think the point that Keith is making is not “pastoral vs forestry”, it’s the sham that is the billion trees programme and that this scheme will go nowhere near addressing NZs 2050 C target. It’s purely a political strategy that has but only a shred of truth to it but come election time it will be enough to convince the electorate that Labour is saving the planet. By the time that it all unravels, Jacinda et al. will be resting their taxpayer padded backsides on a beach somewhere enjoying a glass or two of Cloudy Bay.
Keith
I would appreciate it if you would explain why a cut forest area, replanted, the second time, etc receives no further carbon credits. I would have thought a high percentage of the carbon sequestered, over 50% surely, would remain locked in wood used for furniture, building houses and increasingly other buildings.
You have explained earlier that the carbon credits are just icing on the cake for those planting forests, as those within 70kms of a port are commercially viable anyway – as Roger is saying – and you have been worried about foreign investors’ behaviour with the forests they plant. We have a NZ Super Fund, a long-term investor for super, and Kiwisaver fund managers with stability of funding, who I would have thought would easily be able to justify owning forests, and get the cake icing from carbon credits. I don’t know why NZ Superfund isn’t doing this, but imagine Kiwisaver funds are caught in the stupid marketing trap of presenting a yield to date, which would be difficult to maintain for some customers’ appetites if it was necessary to talk about IRR etc. But since Roger Dickie and others have been so successful offering forestry as a long term proportion of a savings portfolio, you would think that Sam Stubbs for example, as a more enlightened fund manager, and a few others would be offering a forestry ‘product’. No need in this case to sell land to offshore ‘patient capital’ for forestry and potential mismanagement that was a concern of yours in a previous post.
Antipodes22
There is a good argument that those who use wood for a permanent structure should get a credit for that. But they don’t. It would need to be genuinely permanent. There is also an argument that the Indonesians and Brazilians should be paid to keep their forests. But they aren’t. The rules of the game are that credits can only be earned by new sequestration of carbon that is not on land that was deforested in recent times. In the case of NZ, most of the indigenous forests were cut down and turned into farmlands a long time ago so the rules of the game say that credits can be earned for putting it back into some form of forestry.
Yes, as emission trading increases I would hope that the super fund and the Kiwisaver funds would look more closely at forestry. But there are some complex issues to work through about valuations. I think we will see private equity funds dominating in at least the short term, and most of these private equity funds come from overseas.
KeithW
why does it all have to be in pines??? how about rimu/totara/white pine /beech etc as a permanent forest. Tourists dont come here to see endless pine trees.
David,
I have tentative plans that my next article will focus on permanent forests
KeithW
“permanent forests” what are they?
Does that mean they come to NZ to see endless Grass? approx 51% of NZ is in Pastoral Farming. AS far as “endless pine trees”, you exaggerate too much, 6.5% of NZ is in exotic plantation.
At last there has been a response from someone who knows what Forests are about. I have been thinking that mine was but a voice in the wilderness. Cheers Roger
David Monagan, it doesn’t have to be Pine, Its just about how long you wish to wait. As an example a 50 year old Pine will sequester as much Carbon as a 500 year old Rimu. There is a good chance that you and/or I could see Pines grow from seedling to and an old (50 year) tree. There is not much chance of us planting a Rimu seedling and watching it mature. There would be no commercial advantage in growing Native trees but it would give a lot of people a warm fuzzy to grow some Natives. It is just where would you plant these Natives and how do you fund it and protect from them from a change in status or rules or government etc
Why Is carbon sequestering in grassland not being given credit. It seems as if the current administration has no idea of the amount of carbon placed in the soils by the roots of grasses, or the harvest of carbon from those grasses by livestock. You look at the CO2 breathed out, the methane belched, etc but not the carbon harvested and then exported as meat milk and wool.
Graham,
I could write a whole article on this!
The starting point is to recognise that credits can only be given for an increase in soil sequestered carbon.
There are some soils in NZ where carbon has increased under pastures. Irrigation on the stony soils of Canterbury is probably the oustanding example. I have seen this occur in my own lifetime.
There are other soils in NZ such as peat soils in the Waikato where sequestered carbon has been lost, with big losses.
As a general rule, soil carbon builds up under pastoral conditions but eventually reaches equilibrium. If these soils are then cropped, then cultivation leads to rapid mineralisation and loss of carbon.
If NZ were to unilaterally provide credits without good underpinning science then the NZ system would be discredited. Currently we don’t have that science.
It would be good to see some more science in this area, particularly in relation to organic fertilisers, but in the greater scheme of things, this may not be at the top of the list for where we need more science.
KeithW
Graham Rennie introduces a very relevant point. I am always left wondering . Livestock are counted in output , but forage is not eligable as a sequester. Thats totally unbalanced principal. The only answer from IPCC, is that grass etc is too short term . So what does that matter?It is a sequester. And in that case why ping animals?
Animals dont create C or extract it from long-storage sources.In fact animals could be a long term sequester in that they store C in bone .
Alan
As above to Graham, it is only long term sequesters that create significant reductions to atmospheric CO2.
Carbon only comprises a very small component of bone.
Keith
None of this discussion would be relevant but for the nonsense of a legislated, so faux market, in something that is neither scare or undesirable. Genuine markets don’t need legislation? After 30 years reading data/detail about climate and C sequestration etc and as a person who was cautiously cynical when I was one of the leaders of FART in 2003, I am now very cynical. My study clearly informs more CO2 is a good thing( who cares about its longevity in the atmosphere because without it we are dead!) and methane is completely irrelevant in terms of climate. No one has shown me verifiable physical evidence that increasing concentrations of carbon dioxide in our planet’s atmosphere have, are or will cause our atmosphere to warm dangerously. I wish someone could put up the evidence that I am wrong.
I repeat, none of the discussion in your article Keith would be relevant but for slowly indoctrinated, gullible citizens and voters allowing a National Party Government to impose the ETS in 2008 and for the nonsense of a legislated CO2 trading concept the ETS allowed.
NZ farming has the international gold standard of subsidy free production. It’s a bit rich for Roger Dickie to call out farming for having a subsidy regarding capital gain, when forestry has massive protection under the ETS.
My only hope for a successful NZ ahead is for the Climate Change/ ETS deck of cards to collapse and take the self interested charlatans with it.
Don Nicolson could I please be blunt. As an educated, responsible, privileged citizen of this planet its time you opened the 1.01 facts on climate change. You are a person of considerable influence in your industry. To be stating that CO2 is a good thing clearly shows that for 30 years of study (your words) you have never read the fundamental drivers of climate change that results from burning over 110 million tonnes of fossil fuels daily (and you say your 30 years of “study” shows “its a good thing” and requesting evidence of how it will cause our atmosphere to warm”. Do you understand the greenhouse effect?
Don, you, as a person of influence I challenge you to the following. To spend a minimum of 4 hours reading/viewing the fundamentals (facts not beliefs) of climate change. Then publish your response being either re-affirming that CO2 is a good thing and that people who have taken the time to understand climate change along with those who administer the ETS are charlatans (your words) or after 30 years of “study” you now have an informed understanding of the facts versus what you have believed for 30 years. And if the 4 hours of study doesn’t shift your beliefs then present to us in this forum the reasons why you refute the fundamentals of climate change ie CO2 is a good thing and the ETS is ……, etc, etc?
You owe this challenge to your children and grand children. And you owe it to leadership of your farming community.
I sincerely look forward to your response to this challenge once you have had 4 hours to commit to reading, viewing and writing your response.
The following are just a few references for copying & pasting into Google. The final two are heavier going but a scan of the chapter headings may alert you to topics of interest
https://www.agmatters.nz/farming-matters/what-is-climate-change/
Productivity Commission_Low-emissions economy_Final Report_FINAL_2018
report-farms-forests-and-fossil-fuels – Simon Upton
Don Nicolsons comments say it all really. When independent surveys show that 95% of scientists believe climate change is man made, why would one swing with the “sceptics and flat earth society” people. I am not a climate change expert at all but I beleive the independent surveys I see that are conducted by organisations like Sydney University etc. Don NIcolson typifies the attitude of th 50 SOG lobby group, they want climate change to go away, so they resort to the word subsidy and anything else negative they can throw at the subject. These attitudes are yesterdays views and simply not relevant to thw world we live in today.
Your first reference is not a scientific paper and is unaccredited. It seems impolite, to say the least, to refer Don Nicolson to such a paper when he has said he has spent 30 years reading about climate and CO2 sequestration, including in all probability far weightier material, and to ‘spend a minimum of 4 hours’ reading magazine articles of your choosing.
Don Nicolson is of course correct: there is no evidence that CO2, or methane, cause global warming, and it is certainly not supported by geological history. At present CO2 continues to rise, but scientists are predicting a period of glaciation, which might explain the breaking of low temperature records over the past few months, and the excessive snow everywhere – corrupt organisations might be able to fake data, but it is hard to explain away the fact of ski resorts having their longest ever seasons.
The idea that we are in danger of having too much CO2 is ludicrous. We are in a period of CO2 starvation in terms of geological history – just consider that the Cambrian explosion, when multi-cellular life first developed, occurred when atmospheric CO2 was ten times was what it is now.
A few hours spent studying the history of the anthropogenic global warming narrative reveals that it is characterised by massaged data, dramatic but failing predictions, and fraudulent research. The very fact that, in order to hype up the 70s-90s warming, Michael Mann got rid of the Medieval Warm Period, when the Vikings colonised Greenland, and the subsequent Little Ice Age, should alert anyone.
We owe to our children not to ruin the economy, the environment, and our way of life on the back of a scam.
Jeff, Roger, Don
I am keen that any ongoing discussion on climate change issues focuses on the science, where we still have lots to learn, rather than on whether particular attitudes or perspectives are relevant.
KeithW
Keith, that’s great, but the nub of your article here was about a concept that for any or all commonsense purpose fails any integrity test. FWIW provided no sector has legislated privilege I don’t much care where trees are planted ( and I am not part of the 50SOG group) Planting a tree shouldn’t be difficult and neither should farming. The property right is sacrosanct – well it used to be but NZ governors are slowly destroying them too. Oh and Roger, it was you who brought up subsidy. I only responded to your erratic assertion. As is often said, ” follow the money”.
‘If sheep and beef farms convert to forestry on a nationwide scale at just half the rate that has occurred in Wairoa this last year, there will be no sheep and beef farms left by 2050’ (Neil Henderson, Gisborne farmer)
The article glosses over the sum of the initiatives put in place to convert farmland to forestry. These include the one billion (pine) trees programme, which PAYS farmers to replant in forest, and the OIA directives, which while on the one hand declare that farmland is ‘sensitive land’ and should not be sold into overseas ownership, but on the other hand allow such sales on condition it is converted to forestry. Recently, the government gave approval to the Japanese forestry company Pan Pac to buy 20,000 hectares before 2022.
Many urban dwellers think all farmers are rich and resent any subsidies to them. They probably don’t think of the rural jobs under threat, those of the fencers and shearers, or the rural towns affected. However it is hard to believe that they would support the determined sale of our farmland to overseas interests, simply to fulfill Jacinda’s One Billion Tree goal.
It also fails to address the enormous cost to the tax payer. According to Pahiatua farmer Lincoln Grant, if his family blanketed their 600 hectare farm in pines, the Government would pay them about $400,000 a year, for doing nothing.
All these actions are supposedly based on the premises that CO2 is causing runaway global warming, and that an increase in global temperature by two degrees would mean Armageddon. Both are nonsense, as Don Henderson has already indicated.
There is no evidence that CO2 causes global warming: the only greenhouse gas of note is water vapour, ie clouds etc, while extensive studies show that CO2 and methane have a negligible effect. there are times in geological history when temperatures have been pretty much as they are now, or lower, while CO2 has been much much higher.
The idea that CO2 is something to be feared is ridiculous. Anyone who has attended a NZ primary school knows the important role CO2 contributes the life cycle. During the Cambrian period, when multi-cellular life first developed, atmospheric CO2 was ten times was what it is now. We are now in a period of relative CO2 starvation. Who knows what effect higher CO2 might have on areas presently in desert?
The claim that another 2 degrees in temperature will bring the world to crisis point – which is NEVER backed up by serious analysis – is equally nonsensical. A huge range in temperatures is experienced in many countries over the year – parts of central Greece, for example, might see 30-40 degrees in summer, but were down to -8 last winter. Average temperatures at Vostok Station, Antarctica, range from −65 ° C (winter) to −42 °C (summer). Two degrees warmer would just mean some more melting at the edges.
As for Roger Dickie’s claim of a 95% consensus …. It has been said that the claim of consensus is the first refuge of scoundrels. But if we’re playing that game, the original (fraudulent) claim of a 97% consensus was based on data which when analysed showed that only about 4% of the scientists involved agreed with the UN’s (politically driven) position on climate. Many petitions from scientists have been presented to heads of government and the UN, protesting the climate narrative. The most well known was an American petition which garnered over $30,000 signatures, all having at least a BSc, and more than 9000 with a PhD in a relevant field (www.petitionproject.org). There is no equivalent in support of the narrative – the recent ‘Claxon’ petition asking the NZ government to declare a climate emergency was an embarrassment, with many signatures from school children and university students, and the “50 top scientists” touted in the media turned out to be 50 post-doctoral students.
Of course many of New Zealand’s top scientists have found the narrative to be fallacious: early critics included former Director-General of the DSIR Dr David Kear, who declared “global warming” to be a dangerous hoax; Dr Vincent Gray, for many years an IPCC expert contributor, who found the IPCC to be totally politicised and “too corrupt to save” and Dr Augie Auer, emeritus professor of and Chief Meteorogist with the MetService. These have been followed by many others who have written extensively on the subject, including important contributions on the role of methane important in the NZ context), such as Dr Geoff Duffy, emeritus professor of chemical engineering, Dr Jock Allison ONZM, and Dr Doug Edmeades ONZM.
I am seeing some signs that the discussion is heading towards a shouting match. I am keen that any debate about climate change remains civil at all times, recognises that ongoing debate is fundamental both to good science and good policy, and that honourable people can hold different perspectives. In terms of underpinning information, I find the website of Dr Ole Humlum, climate4you.com, to be a useful starting point for any debate. It is a wonderful website, updated every month, for those who want to work from the evidence. Here is the latest monthly update: http://climate4you.com/Text/Climate4you_October_2019.pdf
Each monthly update is itself an extensive document, but the home page of the website has signposts that lead much deeper, and the material there will keep the curious engrossed for many hours.
As Albert Einstein once said: “the important thing is not to stop questioning”. So let’s keep the debate civil between honourable people.
KeithW
Thanks for the link, Keith, and I will certainly check it out.
You say, “I am keen that any debate about climate change remains civil at all times, recognises that ongoing debate is fundamental both to good science and good policy, and that honourable people can hold different perspectives.”
I don’t think you quite understand the nature of the climate change debate. An important feature is the suppression and delegimisation of any dissent, widespread as it is. There is heavy reliance on certain techniques which are now automatic amongst proponents, well known to every climate troll on twitter:
1) the fallacious and false claim of consensus
2) the employment of ad hominem, in particular accusations of ‘denier’ and the dishonest equivalence with belief in flat earth.
3) the refusal to debate on a scientific basis.
A typical climate ‘debate’ is one I had recently with a council candidate on sea level. The candidate had seen only what was on the council website; I referred to the Fort Dennison sea level data set, the Wismar, Germany, data set, a study of 225 long term tide gauges around the world, and an analysis of NZ data from the University of Otago (all of which supported an annual global sea-rise of less than 2mm). As a reward for the many hours of study I had put in on this issue, I was simply called a “climate denier”
It comes as a revelation that Roger Dickie and other here have ticked so many boxes.
Barabara,
I agree totally with the three points you make about false claims in relation to consensus, ad hominems such as ‘denier’, and the refusal to debate the science.
KeithW
Dickie / Forestry is claiming that B+L report concludes typical sheep and beef farmer cannot compete with forestry returns over a 60 year period. Dickie has based that on net present value calculated over 60 year period, S+B at $4,225 per hectare return can’t compete with forestry., but that is wrong. S+B return 6 x times the value of (logging ) forestry
As well S&B’s per hectare return of $4,225 does not take into account such things as the permanent local jobs (and requirement for farm service industries) that farming provides.
The point that the Wairoa Report makes is the only way forestry outperforms in terms of net present value is if there are carbon credits or the blocks are never harvested, as the NPV of Forestry from actual logging is only $659 / hectare.
As soon as you add in carbon farming that is where it bumps it up to $8,225 per hectare that assumes $25/tonne price on carbon. What is purposely misleading people is that the only way forestry becomes better is because of the ETS. The whole afforestation thing, on good food producing land, is driven by speculation.
Dickie and carbon forestry are very selectively taking parts of the B+LNZ report to suit their agenda. Bottomline, forestry can’t compete without carbon credits. Forestry returns are logs only
And as a member of 50SOG I resent the derogatory term “privileged” Roger Dickie (of all people) chooses to use. Whether we are self made ( we are ) or whether we inherited tracts of family land (xxxx), every NZ is privileged to call NZ home. What we do with our land and what we do for our country will determine whether we used any privilege for the good of others, or just ourselves.
Thank you for this.
We should also bear in mind that China is planting huge forests now, with the intention of covering a quarter of its land area in forestry. These will come on-stream at about the same time as Jacinda’s 10 billion pine trees. it will be interesting to see how New Zealand competes, given that unlike food production and other industries, there is hardly a question of quality.
I post this comment from Jock Allison at his request, after his own attempt failed. I remain a little concerned about the need for all parties to debate with respect.
Keith W
This is a reply to Jeff Tombleson from Dr Jock Allison:
Jeff Tombleson takes the position of “authority” on the climate science, believing everything he has read in the past. Worse than that, he attacks Don Nicolson in a classic ad hominem way with no scientific basis. His references proffered to Don are:
a) the “Productivity Commissions’ report re a Low Emissions Economy, released from the Office of Climate Change Minister James Shaw in August 2018, but which specifically excluded “any focus on the veracity of anthropogenic climate change”, and thus is not a reference for consideration on any aspect of the science. 588 pages of a dreary consideration of a Low Emissions Economy based on faulty assumptions. In other words a worthless exercise produced at enormous cost. If you want to be certain that your report will not be read, then make it almost 600 pages long!
b) The second reference is also to a weighty tome from the Commissioner for the Environment’s office, the main recommendation of which is that the ETS should be modified and that forestry should only be used to offset methane from cows. Mr Upton also noted that methane and nitrous oxide were not in the atmosphere as long as CO2, and thus should be treated differently. Minister Shaw rejected these recommendations outright virtually before the report hit the press, with no reason even remotely credible – we assume Green Ideology.
c) Tombelson’s third reference was a “popular” representation on a farming site which simply regurgitated the flawed IPCC science, and adds nothing.
Three pictures for Jeff Tombelson, Roger Dickie and the forestry lobby to consider; as it isn’t possible to post pictures, please click on the URL:
1) The projections of increasing world temperature are based on computer models, not on reality – the climate model projections (on which we rely for government policy) overestimate temperature by 2 to 3 times. See https://www.climate-lab-book.ac.uk/comparing-cmip5-observations/.
2) Adding more CO2 to the atmosphere will not cause much warming at all – additional increments of CO2 have very little effect on temperature, see Figure 2, Allison & Sheahen (2018) http://bit.ly/2TgPMLA.
3) The half- life of additional CO2 into the air is about 10 years – yes, CO2 is a short term gas! See Figure 8, A J Allison Submission on the Zero Carbon Bill, http://bit.ly/allison819.
C14 CO2 acts chemically identically to C12 CO2 in the atmosphere (C12 is the usual atomic weight of CO2), C14 and thus C14 CO2 was caused by atmospheric nuclear testing in the 1950s and 60s which gave a rather serendipitous opportunity to test the half life of human induced CO2 in the atmosphere. The results are very clear. Our excellent commentator Keith Woodford, along with the IPCC and government scientists world-wide, are wrong when they contend that CO2 is a long term gas, in the atmosphere for up to thousands of years.
Further a comprehensive amicus curiae brief to a Californian Judge by three American professors – http://co2coalition.org/wp-content/uploads/2018/03/Happer-Koonin-Lindzen.pdf?utm_source=Happer+Koonin+Lindzen+Amicus+Brief&utm_campaign=CO2%2C+A+Climate+Surprise&utm_medium=email – provides an excellent summary (below) of climate science.
1. The climate is always changing; changes like those of the past half-century are common in the geologic record, driven by powerful natural phenomena.
2. Human influences on the climate are a small (1%) perturbation to natural energy flows.
3. It is not possible to tell how much of the modest recent warming can be ascribed to human influences.
4. There have been no detrimental changes observed in the most salient climate variables and today’s projections of future changes are highly uncertain.
We must therefore conclude that the legislative path (The Zero Carbon Bill) that New Zealand is taking, will not have any recognisable effect on the weather and climate. This comment applies also to the Paris 2016 agreement and any actions from various countries arising therefrom, see https://www.lomborg.com/press-release-research-reveals-negligible-impact-of-paris-climate-promises, where Lomborg asserts that meeting all of the Paris commitments from about 190 countries will have a negligible effect on world temperature, and New Zealand’s own Professor Emeritus of Engineering at the prestigious Cambridge University, Michael Kelly has pointed out just how impossible the rapid decarbonisation of the world’s economies actually is https://www.thegwpf.org/prof-michael-kelly-energy-policy-needs-herds-of-unicorns/.
New Zealand with only an assessed 0.17% of the world’s emissions seems to think that destruction of parts of the agricultural industries will save us all from overheating.
Good luck with that: we will soon find that this euphemistic “leading the world” doesn’t make biological or economic sense.
Jock,
I have never intentionally stated that CO2 stays in the atmosphere for many hundreds of years (or thousand of years), but I have also never publicly challenged the dominant position about CO2 atmospheric life. At the other end of the spectrum, I may have stated (although I don’t recall doing so publicly ) my doubts about the Ed Berry hypothesis that says that CO2 lasts in the atmosphere for less than 10 years. I remain open minded as to where the correct figure lies and I would like to observe (from the sidelines) ongoing investigations.
I note the Keeling Curve, and the absolutely fascinating saw-tooth seasonality thereof, and I also note that the amount of additional CO2 apparently in the atmosphere over the last 70 years is only about two thirds of the anthropogenic emissions .
I remain very cautious of the Bern equations in regard to CO2. On the other hand, I also believe that Ed Berry is likely to be mistaken. Yes, individual molecules do stay in the atmosphere for only a few years and this is what the C14 evidence tells us. But the system-wide effects on gas concentrations are not that simple.
I acknowledge that to the extent ocean temperatures have warmed then that will have led to additional outgassing but I don’t believe that can explain the Keeling Curve. From memory, the ice evidence is that additional net outgassing from 1 degree C stabilises at about 10ppm.
If I had to suggest a single point figure for atmospheric half life of an additional 1ppm in the atmosphere, it would be somewhere around 40-50 years as I believe that is where the empricial evidence leads. The average residence time is always more than half life for a first order function, and there is also the issue that a few molecules do hang around for millenia because strictly speaking the decay function is not first order.
But I say all of the above as elements of the issue that need to be considered. I regret that it seems that open debates on these matters cannot be held, but instead are destroyed by tribalism, ad hominems and condescension towards those with a differing perspective. My own caution about involvement in such debates is the futility of shouting matches and the opportunity cost of invested time. One gets caught in the middle and attacked from all sides. But gosh, these issues are both interesting and important.
KeithW
Thank you, Keith Woodford, for posting the response of Jock Allison.
It is extremely useful to have the input of a scientist of Dr Allison’s calibre. I am of course familiar with Dr Allison’s work on the role (or not) of methane in global warming, as every New Zealander with an interest in the climate issue should be, but there are some important (and referenced) points made here in relation to CO2 and to the issue as a whole.
‘Climate Change: Everything New Zealand needs to do to get to net zero carbon’
Plain English investigative journalism by Joel MacManus – well done, we need many more journalists like Joel
https://www.stuff.co.nz/environment/117587959/climate-change-everything-new-zealand-needs-to-do-to-get-to-zero-carbon?cid=facebook.post
Roll on the NGO Climate Change Commission to determine the detail of how the emissions reduction milestones are to be met. And I suspect there will be some pleasant surprises for farmers regarding the very modest minimum reduction of the short lived GHG methane of only 24% less than 2017 emissions by 2050. Fingers crossed that technology emerges to bring about the maximum 47% emissions reduction by 2050.
Science Warning: Contents may offend and be distressing to those who don’t understand the Greenhouse effect primarily resulting from burning over 110 million tonnes of fossil fuels DAILY.
It is generally considered that human CO2 is about 3 to 4% of the total flux. Knowing the amount of fossil fuel usage and the amount of cement made the human contribution is probably fairly accurate. The natural flux however involves a lot of guess work and is most probably underestimated which would make the human proportion less that currently stated.
The IPCC claim that humans are responsible for the increase in CO2 since pre industrial times is predicated on the claim that CO2 lasts for hundreds if not thousands of years, so what humans add accumulates year on year. The radioactive 14C from the nuclear tests that Jock mentioned plus the work of many other scientists makes it clear that that claim is not valid. Even on the IPCC’s own charts it can be seen that about one quarter of the atmospheric CO2 is replaced every year.
Secondly, the proportion of CO2 in the air compared to dissolved CO2 in the ocean is determined by Henry’s Law and that ratio is dependent on the sea surface temperature. Water at zero degrees holds twice and much dissolved CO2 as water at 20 degrees. The exchange between air and ocean is an ever ongoing attempt to reach equilibrium and I suspect that the IPCC underestimates then full extent of that flux.
Now Keith mentioned that he thought a 1 degree rise in temperature was not enough to account for the increase in atmospheric CO2 observed, but one cannot just look at the SST increase over the last 50 years or so, one has to take into account the ocean currents that bring water up from the depths of the ocean compared to water now descending to the depths.
The ice cores from Antarctica show clearly that during the interglacial events CO2 rises or falls some 200 to 500 years after the temperature has changed. This is easily accounted for as deep ocean currents like the thermohaline current take some 500 years to resurface after its waters descended. Until those surfacing waters have reduced their CO2 to the values that the now warmer water can hold then atmospheric CO2 would increase.
So if the SST was colder when the current descended then it would have a higher CO2 content than the present surface water. When it surfaces and warms to the now surface temperatures it will release that CO2 to the atmosphere as determined by Henry’s Law.
The rise in CO2 that we observe now could well be from water that descended 400 to 500 years ago in the middle of the little ice age.
There is also the question of how good are our estimates of past CO2 concentrations. That which comes from ice cores from thousands of years ago is OK, but ice takes up to 100 years to become totally sealed from diffusion with CO2 atmosphere. During an El Nino CO2 rises 11 months after SST rises (and falls 11 months after the SST falls) That change would not be reflected in ice cores so one has to be very careful about comparing ice cores or other CO2 proxies with present measured CO2 content. For example, there were a number of direct measurements of atmospheric CO2 in the first half of the 20th century that showed CO2 peaking at about 400 ppm in the late 30’s early 40’s, I do not know though, where these tests were conducted so they may be contaminated by the environment. Mauna Loa for example rejects some 90 something % of readings (if I remember correctly) – anything above their lowest values is considered contaminated.
However the point is that reliable direct measurement of CO2 has only been available since 1958 which leaves a gap of uncertainty between those measurements and ice core proxies.
To throw another spanner in the works. Over geologic time CO2 decreases as marine organisms that form calcareous shells , mainly plankton, deposit their shells on the sea floor to become limestone. Increases in the historic record arise from major volcanic events such as the Siberian Traps (252 mya). Earth has some 60,000 km of mid oceanic ridges that are spreading zones for the Earths crust. Volcanic activity occurs constantly all along this ridge be we are not aware of them as they are sufficiently deep that water does not boil, even at 1000 degree temperature of molten rock.So we have no surface indication of these volcanic events except in Iceland where the ridge surfaces. These volcanoes are however spewing CO2 into the ocean all the time. A slight increase in the rate of that volcanism would easily account for the present increase in atmospheric CO2. The problem is that we simply do not have a clue as to the extent of this volcanism, let alone how active they have been over time.
At the end of the day it is the ocean, SST and volcanoes that determines atmospheric CO2, not humans.
Thanks Peter
There is lots to cogitate about in what you say. At this stage, I think perhaps your last sentence remains as a postulate rather than a confirmed fact. Also, I think that your statement that ‘a slight increase in the rate of volcanism would easily account for the present increase in CO2’ need modelling evidence of the systems dynamics.
Are you aware of any empirical evidence of CO2 in upwelling and downwelling waters? It should not be too hard to measure, with sealing of containers at the point of measurement. Also, if deep ocean volcanoes are the source of increasing amospheric CO2 then presumably it should be possible to find the evidence in upwelling waters?
I am somewhat cautious about the implied strength of the relationship between the two way CO2 movements between the atmosphere and the oceans. If this were correct, then how did the C3 plants survive the major ice ages? And although any volatility in atmospheric conceentrations will be dampened in the ice core measurements, I would still have expected to see some evidence of this.
It seems a remarkable coincidence that the undersea volcanoes have chosen the last 50 or so years to vent in this way.
You mention that water holds double the CO2 level at 20 degrees comapred to zero degrees. Is this a linear relatioship? I presume that physicists must have measured the shape of this relationship as it would be very easy to do in the laboratory.
My own perspective is that the dominant hypothesis that increased atmospheric CO2 is caused by human actions is probably correct. However, if the IPCC hypotheiss of it staying in the atmosphere for many centuries is correct, then atmospheric CO2 should have been increasing even faster than it has. This leads me to a perspective that the atmosperic life of CO2 is indeed considerably shorter than hypothesised by IPCC scientists, and I see some additional evidence for this in the seasonal sawtooth within the CO2 data. But to then accept that the atmospheric life is as short as say 10 years years seems a step too far given the empirical data of atmospheric levels at both Mauna Loa and Baring Head.
I spend some time in my own ‘thought experiments’ in relation to the step from the C14 evidence to the question of atmospheric CO2. The Ed Berry position would seem to be that it is a simple step based on Henry’s Law. But I am not so sure of that. I think the dynamics of the situation may bring in considerable more complexity.
There would seem to be scope for some system dynamics modelling to explore feasible scenarios. However, doctrinaire attitudes seem to mitigate against these questions being addressed within establishment science. It does seem remarkable to me that knowledge about the dynamics of CO2 within the oceans and the atmosphere has not progressed further in the last thirty years.
KeithW
This comment is from Gary Kerkin. Apparently WordPress was not behaving for him so I am posting it on his behalf
Keith, I have been watching this conversation with interest. The information from Don Nicholson, Jock Allison, Barbara McKenzie, and Peter Foster is sound, despite the thoughts of others. The main thrust is that farmers are being vilified by actions intended to diminish the effects of adverse climate change which, simply put, are not necessary.
OK! That is a bald statement but I am very happy to defend it. My scepticism relates, not to changing climate as most detractors assume, but to the disastrous anthropogenic global warming (DAGW) hypothesis that human generated carbon dioxide is solely responsible for alarming climate change effects. There is no indisputable, real-world empirical data to prove the hypothesis. But, if someone can come up with such information I would happily accept it and that person could win about $10,000 from a prize on offer from the New Zealand Climate Science Coalition.
You raised two points in regards to Peter Foster’s comment. One relating to the lifetime of CO2 in the atmosphere, the other regarding the interchange of CO2 between atmosphere and ocean.
If we are to consider, only, the propensity of CO2 to trap infrared radiation in the atmosphere, every molecule has an equal chance as every other molecule of intercepting a photon. How long the molecule has been in the atmosphere is irrelevant. Arguments over lifetime add nothing to the debate.
Ed Berry’s analysis arrives at a point that any competent chemical engineer calls “steady state”. Not “equilibrium” you will note—the atmosphere is not, and cannot be, in equilibrium. But it can be considered a storage “tank” into which CO2 and the other components of air will flow from whatever sources, and from which CO2, etc, will flow to various sinks. If more flows in than leaves, the balance accumulates in the “tank” and the concentration increases. Conversely, if more flows out than enters, the concentration in the “tank” will fall. In my opinion, again, the “age” of CO2 in the “tank” is irrelevant. The quantity at any particular time is! Currently more CO2 is flowing into the “tank” than is leaving, so the concentration is increasing. We must, however, remember the scale of these amounts—that the concentration of CO2 is very small, ~400 parts per million!
Peter Foster has described the relationship between air and ocean well but I’d like to offer another perspective.
You mention Henry’s Law in relation to Ed Berry. Henry’s Law is very well known, simply relating the concentration of, say, CO2 in water and in air either side of a common interface. The constant relating these quantities is temperature dependent and the parameters for CO2/water are well known. It is sufficient to say that at any given temperature the concentration limit on the air side of the interface is determined by the equilibrium partial pressure of CO2, and on the water side, the corresponding equilibrium concentration. In general terms it means that as the temperature of water increases there will be a mass flow of CO2 to the air and vice versa—visualise a glass of soda water. A whole lot of other things will be happening too, which complicates the process which involves mass, energy, and momentum balances and makes modelling difficult.
Peter’s point is that as the planet has warmed, an increase in CO2 in the atmosphere can be expected to increase because of transfer from the oceans to the atmosphere. There is no doubt that this is happening—it is a readily observed physical process. To what extent? Significant but not necessarily dominant. After all, it sits on top of natural processes which have existed over geological time.
Peter mentioned that ice-core analyses show that changes in temperature precede corresponding changes in CO2. He mentions a lag of 200 to 600 years. Other papers I have read suggest possible lags of between 600 and 1,200 years. A simple thought experiment would suggest that CO2 increase over the last 300 years could have been generated much earlier as global temperatures rose into the Mediæval Warm Period (MWP). Or, more recently, as global temperatures increased out of the Little Ice Age (LIA). There is an interesting conundrum. If CO2 concentration changes are related to the MWP, will we see a correspond fall in the next century or so?
Hi Keith,
Quite a few questions there and no short answers. Perhaps a few general comments first.
Mid oceanic ridges do not rise about the sea floor because of undersea mountain building, they are elevated because below them is a huge volume of hot plastic rock which due to heat is low density compared to normal rock, gravitational attraction is therefore lower than surrounding colder mantle so it rises higher than surrounding crust. As the crust moves apart, magma rises and cools to fill the gap (this is basaltic rock with low water content so it flows rather than erupts as we see on the surface) smokers and plumes have been observed and I presume composition has been determined but I have not seen those details, While it all appears very slow in terms of our lifetime it is very short in geological time frame, The oldest sea bed rock is only 180 million years old, in that time it has formed at the spreading ridge moved across most of the Pacific ocean before descending in a subduction zone in the eastern Pacific. As it cools and condenses its density increases, it descends into the subduction zone because its density is much greater than the underlying warm mantle so the whole movement of crust across the sea floor is driven by gravity, sliding down a slope created by its increasing density, Now that is very fast by geologic standards. The point of all that is that the formation of new crust is enormous and with its formation is a huge release of CO2 most of which we do not see and cannot measure.
So at the spreading ridge the process is continuous and the volume huge, some estimates suggest some 90,000 volcanoes along the ridges. Gases like CO2 degas from the magma constantly as it rises to the top of the ridge and the depth of crust formed is about 10 km thick. envisage a constant creeping process rather than irregular eruption as we see from volcanoes on land. (this is the same rock type as at Kīlauea in Hawaii and CO2 released is something like 600 million tonnes.year. figures vary widely but as research increases the volume estimates likewise increase.
see https://climatechangedispatch.com/massive-volcano-emissions-warming/
As far as I know, although its some 24 years since I was doing Geology, the rate of crust formation along that 60,000 km is not known well enough to know whether it is increasing or not. I merely offered that scenario as one possible explanation of the current increase in CO2. Ian Plimer (geologist) suggested this some 15 + years ago in his book Heaven and Earth.
That brings us to the chemistry of carbon compounds in the ocean.which is exceedingly complex.
Basically carbon compounds are the buffer solution of the ocean which involves CO2 (g) (atmosphere), CO2(aq) H2CO3(aq) H2O HCO3-(aq) CO3–(aq) and MCO3 (s) where M is a divalent cation such as calcium or magnesium.
There are many different reactions between these species all of which are trying to reach an equilibrium dependent on concentration, temperature and pressure.
Those equilibria change with depth, for example below 4500m called the carbonate compensation depth, carbonates become soluble.
Step back one a moment. remember those organisms like foraminifera that make calcareous shells for themselves, when they die those shells fall to the bottom to form limestone, but limestone does not form if the sea bed is deeper than 4500m in fact they redissolve. So over all the oceans we have plankton causing a rain of dead shells to the sea bed which forms limestone at a rate of about 40 mm /1000 years, but if the water is deeper than 4500m then that rain dissolves and adds to the carbonate concentration of the water. (which probably reacts to form bicarbonate)
In places like the west coast of South America, the current against the land forces part of the thermohaline current to the surface providing nutrients from depth to make good fishing grounds but causes cold dry onshore wind which is why much of that coast is desert (Kalahari is formed from the same cause) El Nino suppress this uprising current and stuffs the fishing.
Getting back to CO2, When these currents arise and warm then CO3 either precipitates or forms CO2 to re-establish the warm surface water equilibria.
The long and short of all of that is that the chemistry of carbon compounds in the ocean is exceedingly complex.
Consider these reactions: (using to indicate reversible reactions attempting to reach equilibrium) I will use H+ for simplicity in place of the correct form which is the hydronium ion H3O+
CO2 (g) atmosphere CO2 (aq) ocean
CO2 (aq) +H2O H2CO3 H+ + HCO3- (all aqueous)
HCO3- H+ + CO3–
CO2 + CO3– + H2O 2 HCO3-
CO3– + M++ MCO3 (s)
Now all of these reactions have their own equilibrium constants and all behave according to Le Chateliers principle The current concentrations in the ocean are the net sum of all of these equilibrium reactions but this will vary with depth and temperature. In surface waters at pH 8 the dominant form is bicarbonate which is 100 times the concentration of CO2(aq) and CO3–
However you can see from the 2nd and 3rd reactions why ocean acidification is crap, if acidity increased the reaction would go to the left and produce more CO2. this is buffer solution in action.
The principles of chemistry are well established, but not by the IPCC
You asked if the solubility was linear, no, but not far off it at lower temperatures
solubility 0.067 at 0 °C value is mole fraction x1000
0.048 at 10 °C
0.035 at 20 °C
You question how C3 plants survived if there was two way exchange between water and atmospheric CO2 Keith if you email me I can send you a very pertinent graph of dust storms during the depths of the full glacial period.
The IPCC estimates the exchange to be of the order of 90 odd gigatonnes but I suspect that is just a guess. Remember that 71% of the Earth’s surface is ocean. remember too that every forming raindrop will dissolve some CO2 and rain it to the surface. I read a paper recently in which they determined that the temperature that counts is a very thin skin <0.1mm that is in contact with the air and that can be different (due in part to evaporation) from the measured SST.
The exchange is definitely two way unless someone wants to rewrite Le Chateliers principle.
When temperatures sea saw down to the coldest times, the last 30 to 40 thousand years show massive dust storms once atmospheric CO2 drops below 190 ppm. C3 plants only survive in perpetually wet environments. The loess along the east coast of South Island, for example, is a wind blown dust that came from the East. Out east 20000 years ago, you could walk to the Chathams just about,, but it had no plants, just bare earth, not just too cold but no CO2, plants could not grow for lack of CO2 so they survived only in places where they could keep the stomata open without dying from dehydration.
Hope that is of some value and hope that I have not been trying to teach the grandmother to suck eggs so to speak.
Regards
Peter
Peter,
Email is kbwoodford@gmail.com
Thanks Peter,
You exposition is very interesting.
I presume you mean wind blown dust from the West not East?
As I read it, we still don’t have any evidence that the volcanic outgassing has increased in the last 60 or so years.
Without that evidence, it is hard to refute the importance of the correlation between human emissions and atmospheric concentrations.
KeithW