ForUm has talked to climate scientist Svitlana Boichenko, chief researcher of the Institute of geophysics of Ukraine's National Academy of Science, and she has explained us what is happening to the climate of Europe, who or what controls the climate of Earth and what weather to expect in Ukraine in a hundred years.
Svitlana, a strong tornado was registered in Simferopol in the beginning of June, and at the same time Odessa was hit by two strong hurricanes. Why does it happen?
- Well, let's say such phenomenon can be considered "normal" for these territories. Tornados appear mostly above seas or on orographic contrasts (significant terrain level difference). Thus, for example, tornados may appear along Volyno-Podilska Upland under certain weather and with terrain level difference of 150-200 meters.
- And what about huge temperature swings? There are theories that it will cause more frequent natural disasters in Ukraine and the world. Is it true?
- Well, climate variability has indeed increased for the past hundred years: droughts last longer, tornados are more destructive and precipitations are more abundant... The fact is that human activity does influence the climate, strengthening the atmospheric greenhouse effect with greenhouse gas emissions. For the past 100-150 years the temperature has been rising really fast, which never happened in the early past.
However, we cannot say that devastating natural disasters are the curse of 20-21 centuries only. Natural disasters happened before, and information about them can be found in chronicles and manuscripts of monasteries, which registered not only historical facts or political events, but also various weather phenomena: earthquakes, droughts, floods, pandemics, etc.
Climate has been changing through the whole millennium. Thus, in the early Middle Ages, period of prosperity of Kievan Rus, there was "little climatic optimum", and in late Middle Ages (15-17 centuries) "little ice age" was registered.
In fact, climate of the planer changes constantly within certain time cycles. As I often say, climate is similar to the character of a capricious woman.
Among other things, the cycling depends on rhythm of volcanic activity - volcanic emissions in lower atmosphere may cause strengthening of greenhouse effect, while volcanic aerosol emissions in upper atmosphere causes cold spell. Aerosols strengthen albedo (reflecting power of a surface), and a part of sun energy returns back to space. Thus, eruption of five volcanoes in February-March of this year might have caused abundant precipitation, including heavy snowfalls and rains. However, this theory needs yet to be confirmed.
Apart from volcanoes, the climate changes depends on processes going on the Sun or in the galaxy, including changes of earth orbit elements - elongation of orbit results into warming periods, but when it tends to circle, cold spells occur. However, frequency of orbit change makes about 100 thousand years.
The ocean also controls the climate to certain extent. It is a huge archiver of greenhouse gases. When it is cold, the ocean absorbs greenhouse gases from the atmosphere making it even colder, and when it is warm it gives the gases back into the atmosphere. Thus, the global ocean can intensify warming or cooling on the planet.
- From time to time, mass media and Hollywood depict apocalyptic scenarios, according to which Earth will either freeze or turn into a desert. Can it happen in reality?
- When long-term forecasts are made by mathematicians, who have no idea about physical mechanisms of climate formation, scenarios indeed appear horrible. Thus, according to the "theory of white climate", the planet can be fully covered with ice. The process may be provoked by volcano eruptions, namely volcanic aerosol emissions in upper atmosphere. More of solar heat will go back in space and temperature will start falling. Then the ocean will play its part, absorbing more greenhouse gases and making weather even colder, which in turn will cause glaciation of polar regions, then of high latitudes and finally middle latitudes of continents. White ice also reflects solar heat, meaning even more of warmth will go back in space, and the planet will eventually freeze over.
However, nothing of the kind has ever happened. The climate system "lives" within cycling, and there is always an external or internal factor to balance fluctuations and "cancel" the catastrophe.
- How about local catastrophe in South Africa, where snow fell and ocean froze over in the beginning of June?
- Western disturbance traditionally dominates in north hemisphere, but with the climate change meridional disturbance may prevail over or a breakthrough of cold air from Antarctic may occur in south hemisphere. This fact was described in research papers of 1960s. Sometimes it happens that air currents from far north or south arrive in low latitudes, including Africa.
- Is it possible to forecast what climate will be in Ukraine in 20 or 50 years?
- For the past hundred years the air temperature on the planet has increased by 0.7-0.8 degrees. We expect it to rise by 1.5-2.5 degrees by the end of 21st century. According to pessimistic scenarios, the temperature may rise by 3-4 and up to 6 degrees. It is possible, but not probable.
The temperature in Ukraine has increased by 0.6 degrees on average - by 1.2 degrees in north, north-east and north-west, and by 0.4 degrees in south and south-east. In the future it may rise by another 1.5-2.5 degrees. The most vulnerable regions are the Carpathians, Crimean Mountains, Black Sea and Azov Sea coasts. The sea level there has increased by 12-15 cm for the past hundred years. The results of theoretical simulation show that with temperature rise by 3-4 degrees the south-east of Ukraine may turn into desert. Subtropical anticyclones from Middle Asia and Africa may move to middle latitudes and affect Zaporizhya, Donetsk and Luhansk regions. In fact, couple of years ago these regions already suffered hot and dry August, caused by anticyclone from south-eastern Asia.
- There is no common opinion on global warming and adverse effects of human activity on nature. Green Peace members, for example, call to reduce production rates, while Danish economist and ecologist Lomborg Bjorn states that warming is inevitable and Kyoto protocol is a waste of money. What is your opinion on the matter?
- As for Kyoto protocol, I don't think it can change the situation. Its mechanisms do not work. Reducing emissions is a good and right idea, but America, Europe and other developed countries want to live well and comfortably. We all want to have air conditioner, cars and warm houses.
Now some words about alternative energy sources. With the students we have calculated possibilities of using windpower devices and solar batteries in houses. It turns out taking energy from the net is cheaper. The pay-back period of these devices is about 10-20 year, but the equipment itself will not work that long. Moreover, production of photocells is harmful. Solar cell batteries must be cleaned regularly, but the process contaminates water. Windpower plants cause soil erosion and sound pollution. It means that until the mankind finds really effective mechanisms of using alternative energy sources, anthropogenic effect on nature will hardly decrease.
- Do you think people will ever be able to control weather and climate?
- I don't know as for ever, but for the moment the men cannot concentrate necessary amount of energy to influence natural phenomenon.
Back in soviet times academicians Budyko and Israel proposed to bring aerosol substances in the upper atmosphere to increase albedo. However, it is not possible practically.
We know that US suffers from typhoon, so Americans repeatedly try to learn to stop them - they tried to weaken tropical cyclones by flying aircraft into them and seeding with silver iodide, which was supposed to cause supercooled water in the storm to freeze, disrupting the inner structure of the hurricane; they tried to send weather squadrons against turbulent fluxes. All the attempts, however, failed.
Maximum what we can do now is to seed clouds to clear sky over Crimea beaches or over cities during parades.
- Svitlana, you were in Germany during the period of floods in Europe this summer. How did Germans fight the disaster and why did it happen in the first place?
- Fortunately, I was in the part of Germany which did no suffer much, but I know that the authorities involved the army and voluntaries to deal with consequences, so there was no food shortages.
German meteorologists argued a lot on the matter. The water level reached 8.5 meters, and I think that consequences of the natural disaster were aggravated by the system and methods Germany and Czech Republic carry out melioration and water draining. These are countries of former social camp, which explains a lot. In western Germany it rained heavily as well, but no catastrophe happened. In Holland, for example, they say the weather changes 20 times in 15 minutes, but the ducting and water draining system is constructed to prevent any disasters.
- Will the floods in Europe and Ukraine damage the yield of this year?
- Agricultural lands were flood in some parts of Europe, thus problems with food provision may occur. Ukraine, howevr, has withstood the flooding period better than Germany or Czech Republic and can supply affected countries with its production. The important thing is for our production to meet European standards.
It turns out it is important to know not only about the weather in our country, but about the climate of neighbors as well. From this point of view, climatology stops being a pure science, but can be considered a part of politics and economy.
Alina Yeremeyeva, photos by Viktor Kovalchuk
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