Dr. Janusz Filipiak is the head of the Department of Meteorology and Climatology of the Institute of Geography of the University of Gdańsk and an international advisor to the Permanent Representative of Poland to the WMO at the Institute of Meteorology and Water Management - National Research Institute. His scientific interests include historical climatology, climate change and variability as well as the causes and implications of the process of international climate negotiations. In the latter issue, he was a member of the Polish delegation to the United Nations Framework Convention on Climate Change (UNFCCC) meetings.

PAP: Is snow falling in and around Koszalin at the end of May normal?

Dr. Janusz Filipiak: You could joke that the occurrence of certain weather conditions and within them, specific meteorological phenomena, is not legally reserved for a given season. We are dealing with the atmosphere - a very dynamic environment, reacting in a way that for many is typically spontaneous, but in fact it is strictly defined by the laws of physics as a reaction to signals and stimuli coming from other components of the natural system, and additionally has its own internal variability. We are, of course, used to a more or less typical course of weather phenomena. Additionally, we tend to believe that in the age of global warming, such situations as the one mentioned above are out of the question. Just like in the past, we still should not close our awareness to phenomena deviating from the climate norm. What happened in Koszalin certainly is not typical, but let us assume that the probability of its occurrence was not zero.

PAP: You are talking about climate warming. How is it changing?

J.F.: Air temperature, the most often mentioned meteorological component, is not the only thing that is changing. It is of course the most discussed one, and the systematically growing trend of the value of this component has been given the specific term 'global warming'. The change in the functioning of the entire climate system much more complex, in fact global warming is only one of the many manifestations of what the entire system is experiencing. Along with the warming of the lowest part of the atmosphere, i.e. the lower part of the layer known as the troposphere, a part of the higher layer, called the stratosphere, located above the zone of moderate latitudes at an altitude of several to several dozen kilometres, cools down noticeably. The rate of air temperature rise is not uniform all over the world. The atmosphere warms up faster over land than over oceans. What's worse, there is already undeniable evidence of this positive thermal signal in the oceans. Especially the upper layer of ocean waters warms up, because the ocean is a receiver of a huge surplus of energy existing in the climate system. Since it absorbs it, its warming is inevitable. More importantly, just as we used to fiddle with the thermometer when we were children, to show to our parents that the expending mercury was a sign of our high fever (and avoid going to school), colloquially speaking, ocean water also follows the same pattern - while becoming warmer and warmer, it also expands. But the reasons for ocean water expansion are not that funny.

PAP: What are the consequences?

J.F.: If we get more and more of this water, it is no wonder that we systematically experience an increase in the sea level. This process is happening all over the world and is of particular concern to the inhabitants of low-altitude coastal areas, including many small island countries. Rising sea level should also be taken into account when considering the possible height of storm surges near the shores - if the storms 'start' from a higher level, they will also peak higher, and perhaps reach farther, penetrating low-lying coasts. All this briefly shows the complexity of the system only in relation to temperature. Its increase additionally implies a hydrological regime. Warmer atmosphere accelerates evaporation, but does this automatically translate into an increase in total precipitation? Not necessarily. Warming atmosphere means an increase in the value of water vapour pressure at condensation takes place. If evaporation does not 'catch up' with the temperature, the conditions for the formation of clouds and precipitation will be destabilized.

PAP: How will it affect the soil?

J.F.: We are already experiencing extended periods between individual rain events during the warm season in Poland. After such, an often long, dry period, comes violent rainfall that exceeds the capability of the environment, be it natural or closely related to man (city), to absorb and effectively manage such a rainfall. We could continue talking about other components of the natural environment, unfortunately, to no end. One thing, however, is still crucial - these are all components of one specific system of our planet, closely cooperating with each other. Changing one or two such components causes the entire system fall out of dynamic balance.

PAP: What is the cause of global climate warming then?

J.F.: Just one word will suffice in the indictment: humans.

PAP: This is a brutal statement.

J.F.: In last year's Working Group 1 IPCC report devoted to the physical science underpinning the climate change, the Sixth Assessment Report (WG1 contribution to AR6), at the very beginning we have the sentence: 'It is unequivocal that human influence has warmed the atmosphere, ocean and land'. Of course, justifying the accusation requires, something more. Therefore, a number of claims and evidence in the present case were subjected to objective and comprehensive criticism. All this in order to avoid fashionable accusations of dogmatism and indisputability of claims. In the past, not every opinion of the panel was so absolutely supported by evidence. To additionally show the extent to which we as a scientific community are convinced of various facts, the degree of certainty of each statement is expressed by means of a suitable qualifier (from very low to very high). Similarly, the likelihood of a specific effect or result is expressed - from practically certain to extremely improbable. All this in order to make the reader aware of the current uncertainty with regard to the course of some facts and phenomena. Science has its limitations and people also need to be informed about them. Everything has its limits, including scientists' skills - it's like forecasts. We are getting better at understanding the complexity of phenomena, but we always need new information to improve the methods of action. This, of course, is an impulse for development - discovering new research areas, creating new ideas. The aforementioned indisputableness is not a manifestation of the absolute in science, but the fact that the opposite side is simply lacking arguments. This, of course, means scientific arguments, as populists will always have arguments, only their quality is simply nonexistent.

PAP: Since we have global warming, can we say that it will only get warmer?

J.F.: The theory of global warming is very far from preaching that 'from now on it will only get warmer'. It is not like that at all. The increase in the global surface temperature of the Earth, found beyond doubt, manifested more or less intensively in individual regions, also includes the phenomena of a short-term decrease in air temperature, at some point even significant and strongly noticeable. However, I have the impression that this perception of coldness is the greater, the more actively a person expresses opinions undermining the existence of the currently experienced radical increase in the temperature of the entire globe. However, empirical evidence is undeniable. I admit that I am a definite supporter of the existence of a modern climate change that manifests itself in the warming of the world, changing rainfall regime, acidifying oceans, imbalance of ice sheets. I am equally convinced that human activity is its fundamental fuel. I analyse literature, I critically approach the information presented in the media. However, I am far from something that could probably be described as 'climate fundamentalism', i.e. not quite rational mantra about the need to re-evaluate all human life  in the context of the inevitable disaster with an almost certain date. The situation is really serious, it requires consistent adaptation and soothing measures, but at the root of everything should be knowledge, not emotion.

PAP: What should you do?

J.F.: If objective sources of scientific information paint such a picture, then such a fact should be revealed at all costs to the widest possible public and political decision-makers, we should explain the situation and how to act to try to remedy it. Rending our garments on the altar of poorly misguided environmental sacrifice may, unfortunately, lead to a result completely different from the intended one - namely repel the public from the topic. In this context, I bow to all my colleagues who maintain such a calm information policy, based on explanation, not fear or demonising more spicy details, in different countries of the world - both globally and locally. The initiative in Poland that deserves all honours is the portal www.naukaoklimacie.pl, whose participants, prominent and consistent scientists, leading authorities in the field of climate science, do exactly that. While mentioning the honourable colleagues affiliated with this initiative, I am pleased to say that that they also value the scientific consensus in interdisciplinary aspects, trying to collaborate as closely as possible with various scientific centres, including two institutions closest to my heart, that is the University of Gdańsk and the Institute of Meteorology and Water Management - National Research Institute. The latter institution is of colossal significance in the field I would call 'adjudication' on matters of change and variability of the climate in Poland. The institute is the only source of information about the state of Polish climate and its dynamics. Since 1919, we have been conducting systematic climate monitoring as the Polish national hydrological and meteorological service.

PAP: If we can't say that it will only get warmer, can we say that we can expect an increase in average annual temperatures?

J.F.: With high certainty and especially in relation to the near future I can answer that we can. As for a more distant perspective - this should be approached with more caution. This is due to decisions to limit modern climate change, made as part of international climate dialogue. I, like any other interested parties, am not able to say how determined politicians, financiers, entrepreneurs, or simply ordinary citizens in individual regions of the world are to consistently take up the challenges associated with the fight against climate change. The quality of remedies and the effectiveness of their implementation will determine the climate system. At the moment, however, I do not have hard arguments to announce our control over the adverse, even in a distant future. I have no grounds for anything other than the initially expressed pessimism as to the direction of changes - in the context of the period until 2030, as well as, for example, 2100. But a negative change will not take place suddenly, here and now. This is a process, it continues, and it will be noticeable, for example, in constantly deteriorating living conditions, agricultural activities, the presence of individual species of plants and animals in their natural environment, etc. Changes will not always be fully noticeable for us, but they will be consistent. And this is what we should be afraid of. As long as there is no spectacular disaster, the public does not take facts seriously. Especially when climate sceptics, some of them equipped with loud megaphones, call for denying what is scientifically valuable, while suggesting their simple, seemingly coherent and rational theories.

PAP: What impact will the increasing average annual temperatures have on the environment?

J.F.: Thick volumes have already been written on this subject, in which every word is worth printing. Behind every forecasted effect of what the nature's system is experiencing there is the most important thing: observation and insightful interpretation. The conclusions do not come from nowhere. The environmental impact of phenomena present in the climate system will unfortunately grow as far as the modern climate change will progress. There will be few places we know that will not experience more or less advanced changes. And the fact that they are already present is evidenced by numerous reports, not only from the world of science. Just look into widely available social media channels to see the images comparing the past and present of carious places - how things visible to the naked eye are changing, for example the sight of alpine glaciers centuries ago and now. However, hidden, imperceptible, changes seem to be of more concern. It is hard for us to believe in something that we do not see. Still, negating the fact of change can lead to a revelation only after the situation gets very serious.

PAP: What do we fail to see?

J.F.: An example could be the phenomena present in ocean waters, but hidden under their surface - progressive acidification of the ocean, caused by dissolving a huge portion of carbon dioxide in water and the washing of western Antarctica ice sheet by increasingly warm waters of the Southern Ocean. You need sophisticated analysis methods to see this type of threat. Next, you need to be determined to interpret them properly and report. The thing that could be considered most dangerous is that many effects not only intensify, but also lead to irreversible environmental changes. What is worth mentioning in the context of the impact of climate change is also extreme weather and climate. We already have evidence of the disturbing system's response in this context, manifested specifically in an increasing frequency of such phenomena, their intensity, or both.

Interview by Piotr Mirowicz

PAP - Science in Poland

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