Weak spots in our effort to solve the climate problem
We are increasingly cornered by climate conditions. It is now or never. The phrase "We're on a collision course with the planet" is more or less becoming a mantra in circles of the higher-ups (see Larry Elliott, see Ángel Gurría). We have to escape from this trap, before it slams shut.
I discuss below the weaknesses in our measuring, thinking, and planning so far.
Main weak points
If something doesn't go your way − like global warming GW − the first key question is: How can that be?
As far as GW is concerned that question is pretty well answered: The outgoing earth radiation is increasingly absorbed by higher concentrations of some gases (= GHG) in our atmosphere. So, the global surface temperature (= GST) must rise higher and higher before the outgoing radiation again exports as much heat as is imported via the incoming solar radiation.
The second key question is: How to stop GW?
Answering that one, you need a formal model i.e. a precise description of the cause-effect relationships surrounding the dynamics of your problem variable (i.e. GST), in a form that makes you a prime player. With the latter I mean: Any description of emission-causing human activity should be linked to decision variables (i.e. cognitive information contents that people use when making decisions) of those (i.e. politicians, companies, individuals) who decide on the structure and the extent of that activity. Otherwise, why build a model? If, within those descriptions, you only display the direct emissions during the consumption of an activity − in the case of air or car travel, for example, the direct emissions per passenger per km − the decision makers (actors) have no idea what they are putting into motion in terms of total emissions when they produce, consume or change such an activity.
It is as if you would make someone decide whether or not to get married by causing him to think only about the ceremony, and not about all that she or he would set in motion in his own situation and in his relationships with others and society.
In short: If you want to make someone carry his burden by holding him accountable at a certain point in his decision-making process − namely GHG emissions caused by him as an end user − then you must also present that burden to him at that point in its entirety per product and service. In a restaurant, you also pay the entire production line (waiter, cooks, building, energy, middleman, farmer) for a meal, and you decide what to eat by viewing prices that accumulate all these contributions. Well, this shortcoming − insufficient connection to the decision dimensions of the emitters − of the current models is a consequence of the multi-sector method of identifying and combating emissions. In the main article, I have already formulated how this link can be much better established.
In addition to the inability of the current models to provide straight-applicable information to GHG decision makers, I note 5 significant shortcomings in what has been researched and constructed to date:
- There has been a strong focus on physical variables, and hardly any on societal variables;
- Among the physical variables, mainly the absorption of outgoing heat by greenhouse gases and their radiation is elaborated, and hardly any attention has been paid to the direct consequences of all the heat released by all the processes (fossil, energy use, nuclear, volcanic, fire, metabolism, etc.) on Earth.
- There is limited visibility of annual emissions of nitrogen oxide, ozone, ammonia and CO2.
- The current view on climate impacts of transport services is too narrow, incomplete and misleading.
- There is insufficient insight into the annual absorption and transformation of GHG by nature (sea, trees, plants, humus, air).
Let's take a closer look at each of the above shortcomings to understand how they weaken our climate planning.
Weakness 1. No reflection on social-economic transitions
There is a strong focus on physical variables (radiative forcing), but hardly any on socio-economic aspects that drive the demand for energy forms. As a result, there are no tools on the table to limit GHG emissions by means of socio-economic reorganizations. This discussion is nihil. See optionally this evaluation. So, the socio-economic dimension − wherein emissions are determined by behavioural choices − is a black hole in global climate reasoning. Everyone is free to run. There is a 'great divide' between, on the one hand, a gigantic government-driven effort to reduce emissions and, on the other hand, a vigorous longing of the population for more and more energy-consuming transport services (car, rail, aviation, shipping, pipeline, cable, radiation) that continue to grow unchecked, also in terms of infrastructure (see this EU diagram). See optionally this core article by Wiedmann, Steinberger and Lenzen on the lack of reflection on possible social-economic structural change.
Weakness 2. Missing topic: Heat generated on earth
Current climate reasoning turns around the absorption of outgoing heat by greenhouse gases, and pays no attention to the heat generated on earth independent of radiation inequilibria by for example residual heat from human-induced fossil burning, energy use, frictional heat, fires, fermentation, metabolism, nuclear fission, volcanic activity. Let's call it the direct heat emissions (DHE).
It would be a bit strange to study the warming of the atmosphere without paying attention to what's going on around us, so it is of course not entirely true. Especially residual heat from combustion processes, for example, does receive scientific attention. There is increasing attention for urban heat islands (UHI). This attention - initially triggered in the 1980s by concerns about malodour nuisance and air pollution - has adaptation motives (i.e. how to keep cities liveable), and does not really look at the consequences for the global dynamics of warming, but we can learn from it how much impact the DHE may have on local climate variables. Fasten your belts, please, because this impacts are huge.
The temperature in cities is diverging more and more sharply from that in the surrounding rural areas. See this short explanation of UHI research. Especially the night temperature is higher. On average, this difference rises to a few degrees, but there are in many mega-cities also days with peaks of 7 to 8 °C and more difference. These kinds of extreme effects of DHE are already making cities increasingly unlivable. Isn't that a bit much unexpected ??
My next logical question:
If local heat emissions do have so much extra effect on the dynamics of local climate, how much global climate effect is actually accounted for by the sum of all local climate effects?
Some general answers have been suggested:
- The amount of heat released by processes here on earth would have changed negligibly compared to the past? No, of course not, in 1870, 185 million tonnes of oil equivalents were sold, and today 11,000 million tonnes are.
- The earth can get rid of the DHE immediately without any problems via outgoing radiation? Yes, okay, but with GHG remaining the same, the temperature would then have to rise slightly to generate so much outgoing radiation. Bo Nordell - who argued that DHE (in his words "thermal pollution") is the main cause of warming - calculated in 2003 that one third of thermal pollution is emitted to space and that a further global temperature increase of 1.8 °C is required until Earth is again in thermal equilibrium. Because he did not cover the GES effects, this figure can only be taken seriously as a signal.
This kind of general reasoning does not get us anywhere. Better to first imagine in detail how DHE turns local climate dynamics upside down. What do they shake up?
My assumption is that the rapid increase in atmospheric turbulence that we have all been experiencing in recent years - unpredicted in fact - is pretty well explained by locally acting heat release (= DHE). By atmospheric turbulence, I mean absurdly intense downpours, incredibly hot nights, super-fast developing towering clouds, absurdly high temperatures on cloudless days with extremely strong dehydration effects. In every country on earth, weather conditions become a succession of caprices that constantly frighten everyone, even when they are not severe. But what else could you expect? Because above every city, every industrial complex, every factory farm, every major (air) port, every major shipping corridor, we emit a huge mass of warm and polluted air (soot, aerosols, NOx, ozone, CFCs, COx, etc.) into the atmosphere every day.
Due to combustion usage and all other energy consumption, it gets pretty warm at the living level. Because of this, the nightly outgoing long-wave radiation is extra high, but because of the upwardly driven heat above the living level and the large quantity of temporary greenhouse gases in that air column, the re-irradiation is also high. Some substances may have a short lifespan, but their renewal is guaranteed on a daily basis, so their effect is permanent. Consequence: the area and also the atmosphere above it cools down hardly at all at night via outgoing radiation and convection. The next day, a new tsunami of heat, soot, aerosols, etc. is released and swirls into the atmosphere above cities, highways, industrial areas, waste incinerators, intensive piggeries, large beef feedlots, busy shipping and airline routes. A more serious consequence must be mentioned: the high temperature above the area draws more and more water vapor into the atmosphere. And this then starts to play a major role in local warming. After all, water vapor is a strong greenhouse gas. Humidity belongs to the three main drivers − next to air temperature and greenhouse gases − of more longwave radiation returning to earth. Thus, the DHE in this form (daily massive dirty heat ejection) may be a catalyst for climate variability in a much broader sense than temperature shifts alone, and in that way cause a lot of turbulence: more heat, more drought, more abnormal downpours and inundations. Soil can become bone-dry (hard as concrete) to ever greater depths, humus burns, and coarser vegetation can dry out completely to the point that only pure carbon remains. And also of course, the higher concentration of water vapour considerably enhances radiative forcing.
Evaluating the DHE purely on the basis of its heat content - and then usually declaring it null relative to the GHG effect and thus setting it aside - is not sufficient, and does not do justice to its features. Where solar radiation mainly causes inert heat in stone, soil, and water, which is further led to depths, or leads to clean evaporation of water above the sea, the DHE is much more released as hot air full of chemical substances, and pops directly into the atmosphere. Much more mobile, therefore, that heat, much more loaded with reactants, much more unevenly distributed and concentrated too, and thus much more expansive and aggressive towards the surrounding atmospheric processes. The DHE pushes dynamics in a certain direction by triggering processes that continually feedback on themselves and other processes. It plays a role in a complex whole. It is far too mono-causal, straightforward thinking, to want to link this effect to one consequence with a simple clause.
So even if it turns out mathematically that DHE heat in itself implies little global positive radiative forcing, and thus a small effect on the increase in global temperature - which would surprise me given DHE's strong positive effect on atmospheric water vapour concentration and on the re-radiation of all GHG - the erratic and turbulent climate behaviours (such as extremes in heat, drought, humidity, precipitation) precisely triggered by DHE may become enough to make the global warming unlivable. One only need to experience one fire or one extreme drought a year to experience your habitat as very unpleasant. A dairy cow can be perfect, but if she roars all day long or kicks you to death once a year while you are milking her, she is worthless.
My impression that the overall climatic effect of the DHE is greatly underestimated has been fueled even more fiercely by looking more closely at the mobility of the DHE that comes from shipping and aviation. What do I mean?
The ground-level heat release from chimneys, vehicles (friction, engine, and exhaust), machinery, hardware, buildings, air conditioners, and living bodies enter the outside air via convection, relocation, and radiation, quite slowly. Engine exhausts, ship pipes, and long industrial chimneys, however, blow their cocktail of dirty hot air steeply upward. Their effect can be observed up to a height of several kilometers. The story is even more extreme with aircraft. They are bringing it everywhere themselves. And not so sparingly. The international research community has not yet paid any attention to this radical mobile heat injection into our firmament.
Let's follow a Boeing 777 during take-off, climb, and cruise phases, in order to determine what this heat injection actually represents. Two GE90 turbofan engines propel this aircraft. First things first: An aircraft jet engine is actually much more of a hot air heater than a thrust producer, because only 35% of its chemical energy input is converted into thrust, and with the rest it leaves behind a wide lane of very hot air (1000 - 2000 °C).
In the present turbofan engines of large jets, a large part of the air is pushed around the engine by means of bypass channels. On the one hand it is used inside the engine via small channels to cool down fusible parts, and on the other hand at the exhaust it is mixed with the exhaust air of the engine (2000 °C) and generates extra thrust through expansion. With the GE90, the bypass ratio is 8.4 to 1.
Let's do the math:
- How much air passes through one engine in total? According to its manual, the GE90 has a mass flow rate of 1,350 kg/s at take-off and 576 kg/s at cruise (at 10,668 m high).
- So how much very hot air does the twin-engine Boeing emit per hour during cruise? Divide 576 by 9.4 = 61.3 kg/s * 3600 seconds = 221 tonnes/hour * 2 engines = 442 tonnes of very hot air per hour.
- How much during take-off and climb phase? During take-off and climb to 10 km, which takes for example half an hour, the hot air emission then becomes: Divide 1350 by 9.4 = 143.6 kg/s * 1800 = 259 tonnes/half an hour * 2 engines = 517 tonnes of very hot air.
How can the magnitude of this aviation DHE be imagined more concretely? Considering that during cruise 442 tons of very hot air (2000° C) are released per hour, as well as more than 3000 tons of reasonably hot air, a very large air turbulence will be generated up there – where the air density is 0.4 kg/m3 at -50 Celsius. That hot column of air will therefore quickly become wider and higher via convection and relocation. From the behavior of contrails and cirrus clouds, we can somewhat deduce both speed, and magnitude of the expansion, and persistence of this heat injection. Bernd Kärcher, in an article (2019) by Fred Pearce, says about this, "I reckon contrail cirrus clouds cover around 0.6 percent of the global skies at any one time - nine times the amount covered by contrails themselves. In areas with high amounts of air traffic, they can merge to cover as much as 38,000 square miles, roughly the size of Indiana, and last for many hours or even days."
Above airports, a hot column of air upwards is fully guaranteed because there are easily 500 take-offs per day, and also during landing and hold-on (= waiting for the turn to land) the turbo-fans are running at considerable speed. For each take-off (for example), a carpet of very hot air is rolled out diagonally upwards over a length of 13 kilometres (average air density 0.8 kg/m3 ), 10 metres high and 50 metres wide, which expands very quickly and strongly heats up the surrounding air layers. Where the CO2 effect and the non-CO2 impacts of aviation together already guarantee about 10% (see weakness 3) of a long-term increase in temperature, the immense mass of heat (DHE) released by jet aircraft in the troposphere. and lower stratosphere plays – besides boosting reradiation by GHG-gasses – possibly a direct and important role in the birth of extreme overshooting local climate behavior. It is not impossible, for example, that the blocking effect of the tropospheric jet streams on the transport of warm air from the equatorial regions to the poles is weakened precisely by the huge mass of very hot air from air traffic, which utilizes those jet streams very intensively as an airline route (because of the free-riding effect). Such a weakening may give an explanation for the extremely overshooting melting rate of the poles in recent decades.
As noted above, since extremes generate more feelings of unlivability than gradual change, the activation of those extremes by the heat (DHE) we ourselves (and the earth itself) generate on earth can begin to complicate our climate planning considerably. Extremes trigger migration (and thus conflict) and redirect investments toward adaptation at the expense of mitigation.
Conclusion (see also Dong et al): The DHE quantity and distribution will be a necessary decision variable for future climate control.
Weakness 3. Blind spots in the quantification of emissions
There is insufficient insight into the extent of annual emissions of nitrous oxide, ozone and ammonia. (note: A recent analysis by the Washington Post suggests that a huge proportion of global emissions (perhaps as much as 23%) are not reflected in countries' reported emissions). A fog hovers over their dynamics, caused by accelerating permafrost melting, ocean warming, and increasing land use changes,. With regard to nitrous oxide, the observation is fairly complete in general terms, but a completely lax attitude prevails towards each source and there is insufficient insight into the dynamics. Each form of emission - namely fossil energy consumption, chemical production and agriculture - should be recorded and regulated much more strictly in terms of nitrous oxide emissions, instead of throwing the blame (very indiscriminately because it is not specified) to agriculture, leaving the other sources (such as chemical plants, aviation, shipping, wildfires) rest in peace, and passively noticing the continuous increase of these emissions.
But we also fail to see exactly the volume of CO2 emissions.. Yes, we know what is burned from what is traded in fossil fuels, but beyond that
- such as subterranean coal and peat fires
- fugitive emissions
- forest fires (10 million acres burned US 2020)
- outdoor directed clean burning (350,000 acres treated with prescribed fire annually in US, in Africa and India and Indonesia this is much and much higher because flat burning is part of daily practice there), and free waste burning
- the natural respiration of humans and animals and plants and soils
we are only speculating or leave it out , such as forest wildfires, general aviation, and military emissions, for example.
More generally, emissions from transport (sea, air, road) are especially poorly put on file and modelled. They have been neglected for decades. Only describing what a transportation device emits during an operation, and not the operations before and after, nor the infrastructural facilities he's using, is really nil. (We will come back to this in point 4).
Let's take a look at some examples of poor accounting of transport emissions.
Insofar as international emissions of aviation are currently increasingly being investigated, I note, that emissions from scheduled flights are included in the determination of direct emissions, but all other air traffic (general and military) is not or not sufficiently included. Is general aviation a lot? Yes, a lot. In addition to about 40.000 commercial aircraft flying on schedule, there are at least 30.000 private or business jets worldwide that go their own way. The U.S. alone totaled 21.800 business aircraft in 2019, 13.000 of which were business jets, and their turnover reached $29 billion by 2020, according to Statistica.
But in addition to those 30.000 private or business jets worldwide, general aviation also contains much more than 400.000 small aircraft (turboprop, helis), because I read on Statistica that in 2109, more than 212.335 aircraft were registered under general aviation in the US alone, plus another for-hire carrier fleet of 7.628. General aviation is mostly downplayed in research articles and not or poorly quantified. Is it nothing? Then it would not be true that 1.2 million jobs are involved in the USA:
Graver's 2% (see their note 3) cannot be true at all. On the web page of the National Air Traffic Controllers Association (USA) I read:
"On an average day, air traffic controllers handle 28,537 commercial flights (major and regional airlines), 27,178 general aviation flights (private planes), 24,548 air taxi flights (planes for hire), 5,260 military flights and 2,148 air cargo flights (Federal Express, UPS, etc.). At any given moment, roughly 5,000 planes are in the skies above the United States. In one year, controllers handle an average of 64 million takeoffs and landings."
So only one third of the flights per day in the US are scheduled commercial, and two thirds are general aviation. The commercial flights are, of course, heavyweights with lots of emissions, but these numbers do suggest that by neglecting general aviation − by the way, planes for hire are also part of general aviation − perhaps 40% of civilian flight emissions are not being quantified.
Similarly, military activity at sea and in the air is both poorly quantified and frequently absent from CO2 emission records. Given the enormous military air and shipping fleets around the world, always operational and in exercise, this probably also involves massive emissions that remain unchecked out of sight of the climate models, because most military powers do not disclose their fuel use and manage their own fuel supply chain. Worldwide, there are about 53,000 military aircraft in use. The U.S. military alone is the largest emitter in the world according to a recent report. And Nato? China? Russia?
Weakness 4. Current datasets of transport emissions are far too curtailed, incomplete and misleading
Transport emissions are a very weak point in the current emission accountancy. Many emissions are visible in the open air but not on paper. And those gaps have major consequences for estimating the emissions of any future increase in long chain production of raw materials, goods and services.
• Why curtailed?
In current models the transport services are usually (if at all) only quantified in terms of direct emissions (= their fossil fuel consumption during operation time), and attributed to an activity (a movement of a product, information, living being). The omission of the infrastructural and depreciation emissions of the transport service is one of the great blind spot in the current methodology, and also in our overall view of what goes on in the production of those services. This applies to any form of transport: by car, truck, train, ship, aircraft, cable, pipe, and radiation.
In the case of aviation, I refer to emissions due to airport construction and maintenance, oil extraction and refining,, aircraft construction and certification, aluminium production, training, safety, catering, chartering and travel agencies, commuting employees, overnighting crews, etc.. For international shipping see this link.
With the current curtailed view on each transport event, a whole bunch of emission activity (that takes place to keep that transport going) is kept out of the field of vision of decision makers, making them to be fooled when calculating the emission effects of changes in economic production volumes (as will be addressed below)
• Why incomplete?
A second major blind spot in emissions accounting for aviation transportation services concerns the failure to include non-CO2 impacts due to contrail and emissions of N2O, NO2, water vapor, sulfate, soot, and other aerosols. This omission is also substantial, and because of aviation growth plans, highly relevant.
A 2008 NL government report (PCCC, De Staat van het Klimaat, De Bilt/Wageningen, 2008) estimates the climate abatement contribution of aviation at 3 to 4 times higher than expressed through direct C02eq emissions per flight. Greenpeace and other environmental organizations have therefore long held that the climate contribution of aviation to global emissions is many times (up to five times) higher than the 2% that suppliers of flights and aircraft tend to communicate.
See a specification of non-CO2 impacts in this diagram from atmosfair.de.
In the recent article "The contribution of global aviation to anthropogenic climate forcing for 2000 to 2018" by Lee et al, a fairly definitive judgment is made:
"Thus, reducing CO2 aviation emissions will remain a continued focus in reducing future anthropogenic climate change, along with aviation non-CO2 forcings. The latter increase the current-day impact on global average temperatures by a factor of around 3 (using GWP*) above that due to CO2 alone".
Conclusion: the share of direct aviation emissions in total anthropogenic emissions should be multiplied by a factor of 4 (i.e. keep on the safe side) in order not to seriously underestimate the warming effect of direct aviation emissions. Until now, the DHE effect (see weakness 2) of aviation has not been evaluated anywhere. That heating effect, if any, could further heighten the aviation non-CO2 forcings.
• Why misleading?
Why are both above desribed blind spots actually misleading? In short, you can't think of any future change in economic volumes without getting your estimate of the resulting emissions completely wrong. Both gaps therefore have major consequences for thinking about emissions, because if you quantify transport emissions so incorrectly, this will propagate through all your model calculations of the expected emission dynamics of future economic developments via parameters in which those transport emissions play a role. Because:
- Suppose that the upscaling of your renewable energy structure (by producing many rural wind projects, nuclear power centrales, and solar farms) requires a great deal of international transportation − for example, related to raw materials (copper, cement, plastics, uranium, steel, silicon), to manufacturing and supply of components, to design and research, to security equipment, to maintenance and repair,
- then you are going to make a very big mistake in the determination of the gramCO2eq / kWh for each of the newly produced types of renewable energy if you have always underestimated the international transport emissions associated with them and thus have not factored into the gramCO2eq / kWh all the global activity (i.e. infrastructural) and impacts (i.e. non-CO2 impacts) of all the transport services that took place to install and maintain your renewable energy.
- From there on that miscalculation starts to sabotage your emissions picture totally, because if you put the climate contribution of an energy type at 12 grams/kwh (as is now usual for nuclear energy in FR for example) while it comes down to 200 grams/kwh (is my rough estimation), then none of the calculations of household use or of a product or service produced in that area with a lot of renewable energy of that type are correct anymore. And so the reduction trajectory towards the desired emissions target in, say, 2050 that you are calculating is as wrong as it can be.
In short: it is no surprise that despite twenty years of emission-reducing measures, the CO2 ppm (and N2O concentration) in the atmosphere keeps rising faster and faster. Of course firstly because of economic volume increases, but secondly because everyone can calculate their long-distance inputs (incl. energy inputs) to be low-emission via miscalculated transport emissions.
Weakness 5. Uncertainty about the natural sinks of GHG
There is insufficient insight into the annual absorption and conversion by nature (sea, trees, plants, humus, air) of greenhouse gases, especially now these natural processes are beginning to take on a different course due to warming effects. The behaviour of seas, lakes and forests is changing dramatically, huge areas of land are thawing, and land clearing is increasing. The foundations are starting to crack under a lot of the hard parameters that we used to work with in the past around the GHG sinks. Many research articles did signal the ticking of this landmine, and the Dasgupta review comes up with a crystal clear conclusion: "Nature is our home. Good economics demands we manage it better. Truly sustainable economic growth and development means recognising that our long-term prosperity relies on rebalancing our demand of nature’s goods and services with its capacity to supply them. It also means accounting fully for the impact of our interactions with nature."
Global heating is in the process of killing us from that super existential corner - we are being attacked from behind.
Would it be absolutely vital, therefore, given the 5 weaknesses in our current climate approach mentioned above, to first better quantify those gaps, omissions, and deficiencies?
No, in my opinion, that would be unwise. The biggest mistake you can make in a life-threatening situation is to allow your thinking time to consume your steering time. You have to know exactly when to stop thinking, in order to strike before it is no longer possible. That moment did come. Kerry pronounced what most people are increasingly daring to think.
“We are already spending the money, folks,” Kerry, the former secretary of state who is now Biden’s climate envoy, said of the recent climate-fueled disasters. “It’s cheaper to deal with the crisis of climate than to ignore it. This is life or death, a challenge to the fibre of our society. The stakes on climate change couldn’t be any higher than they are now. Failure is literally not an option.” (from: Dizzying pace of Biden's climate action sounds death knell for era of denialism, O. Milman, Guardian, 30jan21)
It's a fact that we don't grasp yet the complete dynamics of the climat system, nor did we completely inventarize the present state of all relevant climate state variables. But at this moment the climate system is transforming so rapidly structurally, driving many variables to extremes of bandwidths we have no previous experience with, that the question is whether we can get a grip on its dynamics before the viability of the atmosphere shall disappear. In fact, we now know enough to be absolutely certain about the fact that we are heading for a snake pit full of negative and positive feedback processes, some of which are fatal to all forms of life today. If we keep on thinking and observing, the arsenal of possible steering corrections will diminish rapidly, and we will no longer be able to avoid certain situations. At this moment we have to do a safe intervention, an intervention that is certain to completely kill the current danger that we lose control forever. That intervention is still available to us now.
Which one do I mean?
Look, up till now all regions on earth still have a sufficient vegetal growth potential, and everywhere the population is quite well educated and organized. So we have an enormous amount of willpower available to reduce the emission input into the climate system almost to zero everywhere. We can immediately stop the use of fossil fuel everywhere. We can minimize all flows worldwide. The pandemic proves that it can be done. Of course it can be done. Like any war, it's a question of will and organization (As to how, please see Discussing survival). This step backwards is feasible and safe. We still have that control option. Not for much longer. We are facing centuries of hunger and heat-driven migrations at the cost of even more emissions that will finally crash our atmoshere.
Jac Nijssen, 2021
This article has been written March 2021.