Turkey experienced its third hottest year in 2020, yet now Istanbul and a host of other cities are blanketed with snow. We asked experts to explain the science to us.
Like other parts of the world, Turkey is also experiencing the impact of climate change, as rising temperatures have decreased the gap between winter and spring, as well as increased drought in areas that suffer from the delayed precipitation.
Speaking to TRT World, Professor Doganay Tolunay of Istanbul University-Cerrahpasa Faculty of Forestry, said snow is an expected event in many locations in December and January in Turkey, but for the past few years, there have been high-pressure systems in the country and as a result, the temperatures have been higher than the seasonal average.
“For example, in 2019 December Turkey’s temperatures were 1.9°C higher than the seasonal average, and in 2020 December it was 2.6°C higher than the seasonal average,” Tolunay says. “Turkey in fact has been heating up since the mid-1990s and yearly average temperatures have been rising 1-2°C above the long term average.”
According to Professor Huseyin Toros of Istanbul Technical University Faculty of Aeronautics and Astronautics, Turkey is affected by tropical extreme heat events and polar extreme cold weather. 2020 was an above-average year for the North Pole, so 2020 was a hot year for Europe and Turkey as well.
Toros tells TRT World that in December Turkey was under the effect of high-pressure areas, which caused the first days of 2021 to be sunny, above-average temperatures and below-average precipitation. Whereas last week, with Siberian colds coming in from the north, temperatures dropped steeply and were below seasonal averages. Similarly, Eastern and Mid-European low pressure fields and their extensions caused Turkey to experience a sudden drop in temperature.
Tolunay quotes the Turkish State Meteorological Service when he points out that the hottest year on record in Turkey, 2010, was 2°C higher than the 13.5°C yearly average of 1981-2010. In 2018 this difference was 1.9°C and 2018 was the second hottest year on record. 2020, with 1.5°C deviation from the average, was the third hottest year.
According to Tolunay, it’s not just December but also autumn months that are hotter. For example October 2020 was the hottest October of the past 50 years. “The increasing temperatures directly affect fauna and flora. Because trees blossoming or shedding their leaves, birds migrating or brooding, has all to do with temperatures,” he says. “In summary, looking at long term meteorological measurements, 2020’s ‘false spring’ observed in the months of November and December is a result of climate change.”
Tolunay observes that the temperature changes differently affect each creature: “For example, trees may regrow their leaves if average temperatures are around 10°C, whereas with herbaceous plants this value is around 5°C.” He also advises that temperatures will differ depending on the region. But as a general rule if temperatures were to rise again in the Marmara, Aegean and Mediterranean regions and the monthly average temperatures were 5-10°C for 20-30 days there could be another ‘false spring’.
Toros points out that plants usually flower in the spring, and that meteorological factors are crucial in the development and life cycle of plants. “For plants that provide seeds once a year, they have a developmental cycle based on meteorological conditions. Plants that hibernate slow down or cease their physiological development with the cooler autumn weather. After a cool autumn if the temperatures begin to be above seasonal averages, plants mistake the weather for spring and may even flower. With the cold weather that follows, these buds unfortunately go to waste.”
Toros says that if temperatures were to fall again, this could cause losses in the agricultural sector as well: “Fruit trees may blossom early or grains such as wheat may germinate. If the temperatures then fell, these agricultural plants may freeze. Higher than usual temperatures may also affect hibernating animals such as bears.” Yet he says that while there have been early warm spells in spring followed by a cold front, looking at January and February data, the ‘false spring’ that Istanbul experienced during the last months of 2020 is not very common.
Extreme weather events
According to Tolunay, precipitation in the summer and autumn may be reduced by 50 percent while winter precipitation may increase. These irregularities are sure to affect agricultural land, water sources and forest land. Moreover, “it is likely that all sectors from economy to tourism, from industry to fishing will be negatively affected”. Tolunay quotes the 2018 Climate Change Action Plan prepared by the Istanbul Metropolitan Municipality which foresees 4.5°C increase in temperatures, 30 percent decrease in summer rains, 11 percent increase in evaporation, more arid days, more downpours, monthly average temperatures to be not below 0°C, no snow, etc.
Toros says Turkey will continue to heat up based on climate change projections. Precipitation, he notes, will increase in northern regions while southern regions will see less of it. Toros also mentions that “there will be changes to the heaviness and frequency of precipitation; that is to say, extreme values. Past data and new projections suggest an Istanbul that has become hotter in time, and will continue to do so.”
According to Toros, Istanbul is seeing increasing precipitation based on measurements made in Kandilli since 1911. The scenarios suggest that the Mediterranean Basin, where Turkey is located, is one of the worst affected regions from climate change.
Tolunay warns of “city floods and overflows, forest fires, a decrease in water sources, heat waves, a rise in sea levels, an increase in hail storms and windstorms.” His concern is about children, the elderly and the poor: “If we don’t prepare for these climate change effects, the vulnerable sections of society will be negatively affected. If we don’t protect the water sources, increase the green areas in the city, fight concretisation and unplanned urbanisation, the floods will be more devastating, the droughts and water shortages will be harsher.”
It’s snowing. Will it be enough to fill the dams?
Tolunay points out that the effects of snow will be seen in the following days, and will not be as quickly evident as would rain. Snow would have to melt, infiltrate the ground, and then reach the dams.
Both Tolunay and Toros say the water levels in Istanbul dams are rising: The average level of below 20 percent during December and early January is now at 30 percent as of January 18, 2021. “This is thanks to the rains of the past 10 days,” Tolunay says.
“Looking at past data, in 2008 on January 18 the dams were 26 percent full, and in 2014 they were 34 percent full … The water shortage in 2008 thanks to people using water carefully and productively was avoided without turning into a water crisis,” Toros says. “Likewise, we need to continue our efforts to use water efficiently to avoid a water shortage in the coming days,” he concludes.
Tolunay says that Istanbul may experience droughts and water shortages in the future, so in order to avoid this scenario, he recommends that the city must no longer grow, the water basins be protected and not be opened to urbanisation, and water harvesting be carried out in homes and bigger regions. “Otherwise, you cannot solve Istanbul’s ‘water problem’ by hauling water from kilometres away,” he says.