If warm nights are added to tropical days, it will be about lives, says the climatologist

The Czechia is experiencing the warmest weekend of the year so far. Temperatures should rise above 38 degrees. Climatologist Pavel Zahradníček predicts that the heat season with regard to climate change will come even earlier. “In the future, there may be up to sixty tropical days a year in Czech cities or lowlands. We have to adapt to it, “says an expert of the Intersucho portal and a member of the Institute of Global Change Research, which falls under the Academy of Sciences of the Czech Republic, in an interview with Seznam Zprávy.

Many countries in Europe are suffering from record heat. Temperatures there significantly exceed forty, a hot weekend is also starting in the Czech Republic. Are these manifestations of climate change?

We can take it that way, even if one hot wave is not a sign of change. It’s the intensity. The heat comes earlier and is longer. Heat waves have occurred in the past, this is not a new phenomenon. In the past, however, the hot wave could have a few degrees less on average. The period came later and was not so frequent. In the Czech Republic, we have twice as many hot waves as we did sixty years ago.

This is reflected in the number of tropical days when the maximum temperature exceeds thirty degrees.

Yes, there are even three times more of them in our country than in the 1960s. Tropical days in our country occur on average about eighteen days earlier than in the past. They used to be concentrated in July and August. Now we move more often to May and June, or vice versa at the end of the summer season to September. The length of time tropical days occur.

Unfortunately, let’s prepare for the continuing trend. Some tropical days can be combined with tropical nights, which is a very dangerous phenomenon, especially in cities. The temperature does not have to drop to tolerable air temperatures in hot houses. This has a significant effect on mortality or deterioration in the health of the population.

Pavel Zahradníček, member of the Institute for Global Change Research, belonging to the Academy of Sciences of the Czech Republic

So how many have been added?

There used to be about five of them on average in the Czech Republic. We have ten to thirteen now. In the cities, it is over thirty days. The whole tropical period, when these days occur, has expanded by thirty days.

On the Intersucho portal and other platforms, you monitor changes in the weather in the Czech Republic. Climate change is reflected in more extreme fluctuations. How is this reflected in the monitored data?

This is probably most evident in the manifestations of soil and hydrological drought. We face higher temperatures, so the water dries out of the soil faster. Compared to the past, the biggest engine of drought is air temperatures, which dry up the landscape more intensely. The year 2015 was typical, when a very hot summer came and until then there was not much soil drought in that year. However, the landscape dried up very quickly. We also see in the rest of Europe that drought is more common due to high temperatures than due to a lack of precipitation.

At the beginning of the week, we registered an F1 tornado in Lanžhot in the Břeclav region, and on Thursday, up to 40 centimeters of hail struck in some places in Olešnice in the Blansko region. A crazy week ends with the tropics. Are they also manifestations of climate change?

Extreme weather events in our territory are increasing. We can capture this well statistically during periods of drought and floods. However, in the case of tornadoes and storms, we are not entirely able to say whether this is due to climate change, because the data series is not conclusive enough. F1 tornadoes occur in the country every year, but if they do not touch any built-up area, no one will notice. However, it is generally said that the phenomena are more extreme and may include storms. But even data from around the world do not yet show that tornadoes are increasing due to climate change.

According to the forecast of the Intersucho portal, in the penultimate week of June, up to ninety percent of the Czech territory will be affected by some degree of drought. How likely is this prognosis?

It will depend on local precipitation, there will be some thunderstorms. It depends on how strong they are. However, we use five prediction models, and within ten days, the reduced soil moisture should actually affect up to 90 percent of the territory. We take a mild and worse drought on eighty percent of the republic as very likely. However, if thirty to forty millimeters of precipitation falls in a locality, then, of course, there will be no temporary drought. We are in a time of storms, the phenomena are now local, there may be large differences in a small area. But due to the high temperatures, we expect the drought to spread further.

Should we continue to prepare for the growing number of tropical days?

Yes, unfortunately let’s prepare for the continuing trend. Since the 1960s, our temperature has risen by two degrees on average. As it rises another two to four degrees, the number of tropical days will continue to rise. Climate models take this into account. There can be up to sixty tropical days a year in cities and lowlands. Some can even be associated with a tropical night, which is a very dangerous phenomenon, especially in cities. The temperature does not have to drop to tolerable air temperatures in hot houses. This has a significant effect on mortality or deterioration in the health of the population. Unfortunately, detailed climate observations over the last twenty years confirm all these changes.

So can we withstand such changes in our Central European space?

The Mediterranean will be more affected, where temperatures are really reaching fifty degrees Celsius. Our highs are so far around forty degrees. We may also move further in the highs, but it will be more about longer waves of heat. I believe that we will withstand this in Central Europe, but it will have a greater impact on the landscape and on human health. Urban dwellers will be more affected, so larger settlements should adapt to this. It wants more green, shady places, but cities must first have water to be able to irrigate. It requires a conceptual solution. Air conditioning for every house is definitely not a conceptual solution, especially in an energy crisis.