- According to research, climate change causes soil temperature to increase.
- It was revealed as a result of the research that the temperature rate in the soil develops faster than in the air.
- The moisture content in the soil affects the temperature on the ground. Vegetation cover and climate type are other factors that affect soil temperature.
- According to the researchers, if the land surface is warmer than the air, it can release extra heat into the lower atmosphere, thus exacerbating atmospheric temperatures.
The world is warming. Not only the atmosphere and oceans are warming, but also the land itself. This leads to ground heat all over the planet.
While humans focus on rising air and water temperatures, we’re underestimating the threat of a heat wave beneath our feet, according to a new study.
Soil temperature has received relatively little attention in studies of human-caused climate change, researchers say. This is partly because the complexity of measurements makes it difficult to find reliable data on soil temperature compared to air temperatures near the surface.
But in the new study, a team of researchers from different parts of Germany collected soil temperature data from a variety of sources, including meteorological monitoring stations, remote sensing satellites, the ERA5-Land data reanalysis set, and simulations from Earth-system models.
The team based the TX7d index, which aims to capture extreme heat intensity by averaging maximum daily temperatures during the hottest week of the year.
It calculated this index by making 160 pairs of air and soil measurements at 118 weather stations in Europe, using temperature data between 1996 and 2021, for the air above 10 centimeters of the soil and up to 2 meters above the surface.
The researchers report that in two-thirds of these areas, they found a stronger heat trend for temperature extremes within the soil than in the air above it.
“This means that extreme heat develops much faster in the soil than in the air,” said study author Almudena García-García, a remote sensing researcher at the Helmholtz Center for Environmental Research (UFZ). said.
The study revealed that this phenomenon showed regional differences across Europe, with extreme heat intensifying more quickly in Central Europe, namely Germany, Italy and Southern France.
According to the research, the intensity of extreme heat in these regions is increasing 0.7 degrees Celsius per decade faster in the soil than in the air at levels near the surface.
The researchers examined the frequency as well as intensity of soil temperature increases using an index (TX90p) that calculates the percentage of days per month when the daily maximum temperature is above a certain statistical threshold.
They found that the number of extremely hot days increased twice as fast in the ground as in the air.
“For example, if we currently have high temperatures in the soil and air on 10% of the days in a month, ten years later there will be high temperatures in the air on 15% of the days and in the soil on 20% of the days,” García-García said. says.
This largely depends on soil moisture, the researchers explain, given the key role of climate change in affecting heat exchange between soil and air.
Soil moisture also depends heavily on land cover, meaning the way people use land can make things worse.
For example, in a forest, tree canopy helps reduce soil moisture loss due to evaporation, while trees’ roots can draw water from deeper in the soil. However, in open habitats such as grasslands and agricultural fields, plants can only access soil moisture at near-surface levels.
The ability of extreme temperatures in the soil to outpace extreme temperatures in the air could have significant consequences not only for soil-dwelling microorganisms or the vast food webs that depend on them, but for the entire ecology.
According to the researchers, if the land surface is warmer than the air, it can release extra heat into the lower atmosphere, thus exacerbating atmospheric temperatures.
“Soil temperature acts as a factor in the cycle between soil moisture and temperature and can therefore intensify warm periods in certain regions,” said Jian Peng, Head of UFZ Remote Sensing Department. “In light of these results, studies on the effects of overheating, which mainly pay attention to air temperatures and underestimate the excessive temperature factor in the soil, need to be re-evaluated.” says.
Study Nature Climate Change It was published in the magazine.
Compiled by: Burçin Bağatur