Greek fires raise ground temperatures by up to 10 degrees Celsius

Surface temperatures in the regions surrounding the Greek capital rose by up to 10 degrees Celsius in just one year as a result of devastating forest fires in the summer of 2024, according to a study published by the National Observatory of Athens. The findings, by the institute's Meteorology unit, highlight the long-term impact that the loss of vegetation has on the regional microclimate.

• Satellite measuring fire footprints

Using high-resolution satellite data, Greek researchers tracked changes in ground temperatures before and after major fires in the Varnavas and Penteli areas - two forested regions northeast of Athens. Satellite instruments recorded a significant jump in soil temperature between July 2024 (before the fires) and June 2025, when many of the affected areas were still bare of vegetation. Thus, in the most affected regions, the soil became up to 10°C hotter than the same areas a year earlier. "This is an extraordinary increase, which cannot be explained by normal meteorological variations alone,” the Meteo report says.

• Urban microclimate under pressure

This change highlights an alarming reality: the destruction of vegetation does not only affect biodiversity or air quality, but actually changes the local climate, favoring the formation of heat islands and amplifying health risks. "Vegetation loss has a direct and dramatic impact on the soil's ability to reflect and dissipate heat. Burned surfaces absorb more solar radiation, and the lack of trees reduces humidity and the shading effect,” explained the Greek researchers.

Even though the measurements refer strictly to the ground surface, experts estimate that the air temperature at ground level has also increased, albeit to a lesser extent.

• An increasingly dangerous climate pattern

Greece is experiencing increasingly hot and dry summers, and variable winds contribute to the accelerated spread of fires. Last summer was declared the hottest in the history of meteorological measurements in Greece. In August 2024, a forest fire near Athens reached the suburbs, killing one woman and devastating over 10,000 hectares of land. "The impact of these fires does not stop once the flames are extinguished. The effects are felt for months or even years afterwards, especially in areas where reforestation is slow or non-existent,” warn Meteo scientists.

The situation in Greece reflects an alarming global trend. According to the European Union's Copernicus Climate Change Service (C3S), global surface temperatures were on average 1.4°C higher in May 2025 than in the pre-industrial period (1850-1900). These data confirm that the planet is rapidly moving towards reaching and even exceeding the +1.5°C threshold - considered by the scientific community as a critical limit for human climate security.

• Fossil fuel emissions

Researchers continue to argue that the main cause of climate change is greenhouse gas emissions, especially carbon dioxide and methane, from the burning of fossil fuels (coal, oil, natural gas). These emissions intensify the greenhouse effect, trapping heat in the atmosphere and generating an increasingly unstable climate.

• Post-disaster reconstruction: a strategic urgency

Amidst this climate crisis, Greek experts are calling on the authorities to come up with a plan for rapid and smart reforestation to reduce the risk of new fires and stabilize the local climate. "If we don't act now, the risk is that these areas will become irreversibly hotter, drier and more vulnerable to future disasters,” warn the study's authors. In parallel, civil society and local communities are called upon to participate in replanting, conservation and ecological monitoring initiatives.