From time to time, topical or momentarily fashionable words and phrases appear in the public space. Are greenhouse gas emissions (hereinafter – emissions) also "in fashion", given how often they are mentioned? Can a scientist even answer such a question?
In his work, a scientist is to some extent tied to political processes and the activities linked to them, which is why my answer to that question is: "Yes! Talking about emissions is currently popular and fashionable." This issue is debated in many different interest groups, some of which are reasonable and some less so, some of which are in conflict with one another, but all of which share a greater or lesser interest in the emissions question.
How simple or how difficult is it for a scientist working on a topical subject, knowing there will always be someone ready to criticise everything if the results or conclusions are not to their liking?
Working in science, it is not pleasant to see and read the opinions that appear from time to time in the public space. The situation is twofold – the mind says – better not to look and not to take an interest, but human curiosity wants to know what others think about the issue. I know well that my colleagues in science work with great integrity; whenever we assess or support something, there is always a scientific basis for it.
Why, from a scientific point of view, is it important to talk about emissions and to study them?
Very many developments in the European Union's current climate policy are based on greenhouse gas (GHG) inventories, a technical process undoubtedly grounded in science – guidelines, default methodologies, and nationally approved, empirically based methodologies. The task of science is to substantiate and improve all of the above. Why is it important for scientists to take part? So that the relevant political decisions are adequate. The more precise the GHG inventory, the more precise the political decisions. If a country calculates its emissions incorrectly, the climate targets set will not be correct, and the planned solutions and actions will be just as incorrect. So it cannot be done without science!
I should add that I am talking about the optimal scenario; quite often we see various interest groups simply deciding for themselves what seems better to them. Most often it is non-governmental organisations that decide what they find acceptable or pleasant and what they do not, thereby influencing political processes. In short, loud support does not always have a clear, scientific basis.
How is it possible to calculate emissions incorrectly?
I would say it is more correct to talk about the accuracy of the calculations, which is one of the six principles mentioned in the guidelines (accuracy). Science always strives to reduce possible inaccuracies, because there is very high uncertainty in the land-use sector in which we work. Looking at the European scale as a whole, when all reports are combined, the uncertainty of the results is very high – around 80%, and there are line items where it is even higher than 100%. It should be stressed that this is not a matter of error; every measurement has some variation, reflecting the natural heterogeneity of the processes being measured. For example, if we take measurements from a sample of forest stands, the results obtained have a known degree of representativeness for all of Latvia's forests, which is published precisely that way – say – "such and such falls within a 95% confidence interval", within which the true value also lies. Science, as I mentioned, is constantly gathering extensive data in order to reduce this uncertainty (spread).
Would it be mathematically correct – if the uncertainty (spread) is 80% and the result obtained is 68 – that the true result could range from 28 to 108?
The calculation is correct. When we talk about the inventory, scientists know this variation perfectly well, but more than one person unconnected with science who wants to interpret the results simply takes the average value and concludes that it shows the absolute truth. It does not!
In recent years there has been a great deal of discussion that various kinds of activity, including policy, should be built on a scientific basis. If, for example, someone comes to you for advice and you know very well how uncertain the result obtained is, what can you recommend?
In climate policy, science recommends various climate change mitigation measures. Since there are many ideas and we know how much uncertainty each one carries, we pay more attention to the ones with greater reliability and lower risk of a negative outcome, and we insist on those. A scientist will essentially orient himself towards the most credible option.
Recently zemeunvalsts.lv published an article (1) about the differences between Finland and Sweden in carbon sequestration. In Latvia, too, there are ongoing discussions about sequestration, in which participants tend to talk more about what they personally prefer (it should be remembered that an unwelcome result is not the same as an incorrect result). How large a dataset is sufficient to convincingly assess what deserves attention and what can be set aside?
It is worth recalling a well-known fact – nothing in nature is static – everything changes, including the climate; forest management practice also changes and develops, and so on. We cannot say that in 10 years enough data will have been gathered for us to know almost everything. That will not be the case! Under constantly changing conditions we are continually striving for a better understanding.
Why do the Finnish and Swedish figures differ? I have to say your question is not easy to answer; to avoid being misunderstood, I am not saying that one country calculates correctly and another – incorrectly; in every country the calculations are based on that country's best available knowledge of how to calculate most accurately. One of the pillars of the inventories is comparability, but harmonising the inventories carried out in different European countries is a known problem. Although the inventory guidelines set out the main calculation principles and methods, their parameters are allowed to differ, because under different conditions they need to differ. The reasons for the differences can be various and numerous – for example – the calculation methods, within the limits allowed by the guidelines, can differ in their complexity, which is determined by the data available in each country, and this can affect the result.
I myself carry out inventories in Latvia, and last year I also reviewed GHG inventories in other countries. There are still countries where forest calculations are made using the guidelines' default figures, such as average increment. The European Union no longer allows this; significant carbon stocks cannot be calculated using default methodology, and every country must have a methodology based on its own data. Another reason for differences can be nuances in the methodology for accounting for the achievement of climate targets – there are countries for which, by chance, it is easier to meet their targets, because in the period against which the assessment is made, whether carbon sequestration in biomass is increasing in the country, for instance, there was more logging then than there is now. In other words, historically higher harvest volumes can help meet targets in the future.
Accounting calculations are complicated enough, with many variables. The carbon sequestration figures reported by the Nordic countries are in fact very similar, not to say identical. The main carbon sink is tree biomass. If we open the inventory reports and look at the change in the carbon stock in the forest's living biomass, the average figure for the last five years in Finland is 0.23 t C ha-1 per year, and in Sweden 0.24 t C ha-1 per year. In Latvia it is similar – 0.30 t C ha-1 per year. But if, in the land-use sector, we look at the country's overall situation rather than the average hectare, Finland will always be in a worse position compared with Sweden, because it has four times the area of organic soils. So what we see in the inventories depends on what and how we look at it.
So the point is that, for example, the inventories carried out in Latvia, Finland, Lithuania, Slovenia and Bulgaria could and should be compared.
Exactly! The best and simplest example of the comparability problem is organic soil. For instance, in Latvia, Lithuania and Denmark the definition of organic soil differs, which is why there is debate about how to interpret what counts as peat soil, what counts as organic soil, and how to distinguish organic soil from mineral soil, and so on. Depending on how a country defines organic soil, it becomes possible to determine the extent of these soils. I repeat: every country has its own best available data, and not everyone uses the same data sources.
The next comparability problem – how we assess what emissions come from organic soils. One country uses the default figures from the guidelines, another uses a single fixed emission factor, and others divide organic soils by fertility.
Ideally, scientists from every European country would come together, pool their data, and a single methodology would emerge. We at "Silava" have tried to initiate this – that is – we gather data from the Nordic countries, prepare a research proposal, and work towards a single methodology at least for our region.
Why has that not worked out?
Scientists would like to make it happen, but to get started a research proposal has to be written, which then lands in the hands of anonymous (unknown) reviewers, who read it, assess it, and say: "There are more pressing matters to address."
How often are GHG inventories carried out in Latvia, and how often do the data change (get updated)?
One of the main data sources is forest resource monitoring, which assesses changes not only in the stock of living and dead biomass but also in changes in land use. As is known, this monitoring runs on a five-year cycle. Annual data are also added. Summing up on emissions, there are two data sources – so-called activity data, such as the area of organic soils, land-use change, timber increment, harvest volume, natural mortality, and the other source is provided to us by science, so that it is clear how the activity data received should be interpreted in order to calculate emissions.
Is it possible, from a scientist's point of view, to assess the various practical plans drawn up in the field of climate, concluding what in them is very significant and valuable and what should not have been touched?
Climate measures can be looked at from two sides; there are measures that are already being implemented, with some experience behind them, and those that are only being planned. There are many recommendations, and a great deal is written into policies of various content and direction, but none of it is sufficiently reflected in practical action. Take, for example, the Common Agricultural Policy, where we read: "replacing unproductive forest stands to improve carbon sequestration". When we look at how much of that was actually achieved in the previous planning period, we see – very little, because the idea has not been sufficiently explained or incentivised. Replacing grey alder with a more productive stand would not be complicated, but there is no simple mechanism by which a forest owner can conveniently get a stand recognised as unproductive. The measure is a good one, but little is implemented, evidently because of its complexity. As for measures that are still only planned, the most striking example is the restoration of groundwater levels on areas with organic soils – a widely advertised measure, but one without scientific grounding.
Recognising a grey alder stand as unproductive might not be complicated, but a spruce stand in a spot that is too wet can also be unproductive, where the tree is still fairly young but rot has already set in.
True, but to obtain a felling permit the owner has to prove that this is indeed the case.
From your experience, what should be done in forestry with emissions in mind? If we look at the information that reaches the public space, at its core it is black and white, whereas the truth usually tends to be more colourful.
I agree, viewed from a scientifically grounded standpoint, nothing is black and white. The process can be assessed from a climate point of view, one can assess climate and ecology, and one can also look at the national economy. The more aspects you assess, the more colourful everything becomes.
In my view, before any conversation or discussion it would be important to define clearly and comprehensibly what we are going to talk about and exactly what the subject of the discussion will be. When I observe various meetings, so to speak, from the outside, it becomes clear that each participant says their own piece and there is no common denominator; a good many discussions go this way, monologue following monologue, everyone has had their say, but no one is clear about what should actually be done. For example, what kind of compromise should be reached, and how. What proportion of land area is needed for nature protection, and how should protection be balanced against the national economy?
Speaking of specific things, it is currently very fashionable to talk about reducing the volume of forest felling. Why? What exactly is the goal of the people driving this idea? What is its justification? I would very much like to understand this, because if such an idea exists, it must be justified – are we addressing climate issues, ecology, or what?
If we look at reducing felling volumes from a climate perspective, then yes, we will very quickly meet the climate targets for 2030-2050 – "we leave the forest alone, and as it grows the biomass will increase, and the inventory will show that carbon is accumulating in the forest". What will happen after 2050, or as we approach it? What will we do about the consequences of such a decision – an increased share of low-quality timber, reduced returns for the national economy, reduced carbon sequestration in the long term?
These are important, long-term matters.
Exactly! We assess three aspects (ecology, climate, national economy) and consider what time period we have in mind. Whoever is driving the idea needs to be able to answer clearly – for what term and for what purpose it is intended.
What would the long term be for a forest?
If we model possible scenarios, it is hard to understand much within the span of a single forest rotation cycle. For example, when modelling the afforestation of mineral soil, it is not enough to think in terms of "plant it, fell it"; one has to think in terms of at least three rotation cycles, in other words at least 200 years.
All three are equally important and inseparable – climate, ecology and the national economy.
Correct – you cannot, and should not, assess them separately.
I already mentioned the regulation of felling volumes; it is a hot topic of discussion. It is clear that the pressure non-governmental organisations put on policy is considerable, while politicians want to listen to broader groups within society and gather voters' support, without listening to the voices of scientists. Such a situation is fertile ground for mistakes, since the most popular proposal is heeded rather than the most correct one.
Another hot topic, considered popular elsewhere in Europe and literally being pushed by various European Union institutions – restoring groundwater levels in organic soils (rewetting). In this connection, the first and most important question is – where can one find the scientific evidence for why this is being planned and expected to be good for the climate?
More than a few people regard the journal Nature as being of high scientific quality, yet it is precisely there that I have read an article supporting rapid groundwater level restoration across all organic soils without sufficient scientific grounding. Such calls, made in the name of climate, to change land-use practice on a large scale, without assessing the impact on the national economy at all, are irresponsible.
Searching for the best available information on this question, I found a two-year-old meta-analysis article which clearly states that in the boreal zone, no clearly established significant effect of groundwater level restoration on reducing CO₂ emissions has been found. Yes, on average, emissions do decrease, but not statistically significantly. In the temperate climate zone, for example in Germany, it does happen; in our region there is no evidence, but "in Europe they say it will be good". This is not a climate measure but rather an ecological one. Moreover, the ecological benefits on organic soils that are already substantially degraded and have been long cultivated are also highly questionable, yet the Nature Restoration Regulation calls for focusing precisely on such areas. In my view, that is not sensible.
Six years ago we discussed this question with Ainārs Lupiķis (2), considering how scientifically justified it is to place Latvia on a par with France and Germany. Is this problem still relevant today?
It is still relevant. Europe tends to set common targets, and although, given the differences, each country is allowed its own target, still... one somehow has to fit within the shared targets regardless...
As I mentioned, the problem still exists, for example, if the groundwater level restoration referred to in Germany perhaps "works", it is actively promoted elsewhere, calling for it to be introduced everywhere and saying – it is needed everywhere. But what tends to go unsaid when it is promoted like this is that, to avoid unexpectedly large emissions, it may be necessary to remove the fertile topsoil layer before restoring groundwater levels. That carbon should then be counted as a loss. Nor is it discussed objectively that there is no guaranteed way to maintain a permanently raised groundwater level across an area, and the risk of methane emissions also tends to be glossed over. These and other considerations mean that a single successful case does not justify expecting the same result from every area in the country. Also because it is usually the successful cases that make it into publication in the first place. Even if something works brilliantly somewhere, where is the evidence that the same will happen here? There is no evidence.
From time to time, when discussing the Nature Restoration Regulation, the question arises – if we want to restore something, what is the impact of the restoration process, which is in effect an intervention in the existing situation. Has that been established?
Of course it is an intervention, because ecosystems that were altered in the past have already had time to stabilise. Returning to groundwater level restoration – large areas in Latvia were drained roughly 100 years ago or earlier. That is quite a long time ago; the ecosystem has adapted and stabilised; yes, during drainage there were certainly large emissions, as organic matter oxidised, but that is now the past. Drained soil cannot lose carbon indefinitely; that is simply not possible. Recalling the uncertainty discussed at the start of our conversation, this is how we should look at it – if data are collected from 5 stands, we see large emissions; from 20 stands, we start to see which show large emissions and which show carbon sequestration; from 50 stands – we begin to understand the actual situation.
First of all, the belief that organic soil constantly loses carbon is wrong, and we know the reasons why these figures fluctuate; the real situation should not be modelled for the whole of Latvia, but assessed for a specific site and a specific stand – age, species, and so on. Ten years' experience of emissions monitoring is starting to show that the carbon stock of less fertile organic forest soils is stable or even tends to increase, whereas on fertile soils the risk of a decline in carbon stock is greater. But even that assessment is too simplistic. A relationship with stand age can be observed – in young stands the risk of soil carbon loss is greater, but at monitoring sites where the stand is over 30 years old, organic soil most often sequesters carbon. Accordingly, the variability of the carbon stock over the course of forest development should be assessed not only for biomass but also for soil. Unfortunately, though, outdated convictions can still be heard that hydrologically drained organic soil is unambiguously a source of emissions.
By intervening in this system, we may achieve the opposite of what we intend. A balance has settled in the ecosystem, and now someone has decided that it needs to be disturbed by raising the groundwater level. The result can be undesirable: for example, in soils with a fluctuating groundwater level we more often see nitrous oxide and methane emissions, particularly in the first few years. In this connection we may hear an "explanation" – that this will only be the case for the first 1,000 years, and after that it will be very good. There is no way of knowing that, because there is no data.
Do studies or articles reflect the impact of various unforeseen events, for example, four years of war in Ukraine, sand dust from the Sahara, wildfire smoke from Canada, a volcanic eruption in Iceland? Do these events affect emissions calculations, and if they do, how can they be taken into account?
All of this has to be taken into account when we talk about assumptions – that old forests will go on sequestering carbon indefinitely, because the forest has always sequestered it; that peatlands will go on accumulating peat, because there is peat there right now. Yes, the peat is there, but it formed over thousands of years, under a different climate, and there is no guarantee that these processes will continue. There are scientific papers and reports available which observe, or warn, that within 100 years damage to European forests will double because of phenomena caused by climate change; that tropical forests or peatlands are turning from carbon sinks into sources of carbon. We will unfortunately, most likely, receive such observations and forecasts only more and more often. This shows how dangerous it is to rely on outdated assumptions – just as soil cannot lose carbon indefinitely, a forest cannot sequester it indefinitely either. For a forest to keep "looking good" in the methodology and the documents, it must constantly deliver a certain level of sequestration, and ideally an increasing one, which is not possible, because at some point, as a result of natural processes or natural disturbances, the forest will emit carbon instead. Thinking short-term, perhaps some result will be achieved, but what will we do afterwards? What will follow is a long-term loss of sequestration, losses to the national economy, and so on – there will be far more lost opportunity than gain. Blindly rushing to fulfil a simplistic plan – cut less, and we'll solve the climate problem – the outcome will not be good for anyone.
Discussions continue as to how to factor the war in Ukraine into the calculations for meeting forest-related climate targets (its impact is undoubted). It is not clear how to do that mathematically, and countries are thinking about it. It should be remembered that, once the previously customary imports of timber from Russia and Belarus disappeared, harvest volumes had to increase. As is known, demand for wood did not decrease, and a solution had to be found.
I would stress that demand for wood should be viewed positively, since it means fossil resources are not being used instead. Circumstances forced us to source wood here in Europe. How should we assess that? If we know that in Europe forest management regulation, practice and environmental protection are at a high level, it is a good thing that our wood is not supplied from regions where forest management cannot be called good or long-term. A question we can discuss – from a climate perspective, was increasing harvest volumes in Europe a good decision, or not such a good one? It had to be done, but – the question is how to factor this into meeting climate targets. It should be remembered that, besides the events you mentioned, we also have to take into account bark beetle infestations, drought periods, and forest policy. There are countries in Europe still feeling the effects of bark beetle attacks, where large forest areas are being harvested for firewood. How does that affect the situation, and did it really have to come to that? This is where it is important to talk about planning.
In connection with the Nature Restoration Regulation and the habitat mapping that has taken place in Latvia, I sometimes think of an excellent opportunity – if there are people who do not want to manage their own forest holdings, perhaps it would be better to look for habitats on their properties, instead of taking productive land away from someone else. When I listen to ecologists who say – our forest habitats are in a very poor state... Hold on! About half of Latvia's forests have grown up only in the last 100 years. A century ago the forest area was almost half what it is now. If you find a habitat in a place where there was no forest 100 years ago, and say it is of poor quality, that is, at the very least, an odd thing to say. It is a good thing there is a forest there at all. When in such a situation I hear – the forest is bad, it needs to be restored – I think – restored to what? Unfortunately the media do not explain this – how it was assessed that the quality of the ecosystem is poor, what the criteria for good condition are, and on what basis those criteria were chosen. If something needs to be restored, how far back is the reference point we are looking at, as the target to aim for?
This becomes even more curious in countries where the situation is the reverse. The Nature Restoration Regulation, in my view, creates serious problems for countries that have been responsible enough to maintain and tend their forests and increase their area. Countries that once cleared their forests, on the other hand, have no problems at all, because they have no forest to restore; there is no forest there – nothing to restore. That's it. We have forest, but we still have to restore something. This particular regulation deliberately does not call afforestation a positive measure; I think that is a consequence of the EU-wide pressure from non-governmental organisations already mentioned. That is why it would be more accurate to call this regulation not the Nature Restoration Regulation, but the Improvement Regulation, since it does not require restoring forests for those who have given them up.
There is another question we could discuss, raised more often by colleagues in the peat extraction sector, where from time to time there is talk of replacing peat with "something". Mineral wool sounds bad enough if we think about growing seedlings, coconut fibre means transport emissions, and wood fibre still needs an admixture of peat. Looking at wood from this angle, as a natural, renewable material, does it have an alternative, and what would that be? Plastic, which is tied to fossil resources, or metal, which is also tied to the extractive industry, will not be the right answer.
On the subject of substitution, it has to be said that our sector is periodically challenged with the argument that wood products oxidise over time anyway, so what is the point of talking about them, that it is not a long-term solution either, and that there is no point focusing on it. That is the substitution effect I already mentioned – if I am sitting on a wooden chair at a wooden table, I am not using plastic products. Equally, burning an old chair does not mean burning fossil resources. The substitution effect: 1 tonne of carbon stored in wood products has typically avoided 0.5 tonnes of fossil emissions. If you do the maths, over a few rotation cycles a forest can deliver a substitution effect greater than the carbon stock held in an old forest. So what is the best climate change mitigation measure in a forest? Mathematically speaking, felling is the best mechanism for mitigating climate change. Grow it, remove it, store it, and start again from the beginning. You are not generating the emissions that consuming alternative products would create. I once made this argument against Latvijas Banka, whose representatives wrote that intensive forestry cannot be a climate change mitigation measure. No, that is exactly what it is! But... it will not be easy to explain that to the public.
1. https://www.zemeunvalsts.lv/kapec-zviedrijas-mezi-piesaista-oglekli-tris-reizes-efektivak-neka
2. https://www.zemeunvalsts.lv/inventarizacija-inventarizacijai