The annual report “State of the Climate” is published by the National Centers for Environmental Information of the US National Oceanic and Atmospheric Administration, based on contributions from scientists from around 60 countries worldwide. Among them are Andrea Steiner and Andreas Kellerer-Pirklbauer from the University of Graz.
Climate change in the atmosphere
Steiner studies climate changes in the atmosphere. “The troposphere, the weather layer, is getting warmer in the long term. In 2024, exceptionally high temperatures and record values were observed over more than half of the globe,” reports the climate physicist from the Wegener Center. In the stratosphere above, however, a strong cooling trend can be observed. “These long-term trends caused by human greenhouse gas emissions are overlaid by short-term temperature fluctuations due to volcanic eruptions and the recent large wildfires,” explains Steiner, citing an example: “The impact of the Hunga eruption in 2022 was exceptional. The volcano ejected an enormous amount of water vapour up to an altitude of 50 kilometres into the atmosphere, which led to additional cooling of the stratosphere. In 2024, we are now seeing this effect as the water vapour has dispersed and decreased.” Overall, the long-term trends caused by the rise in greenhouse gases are intensifying. “This includes the increase in moisture content in the atmosphere, with record levels in 2024, as well as in the number of high humid-heat days and extreme precipitation,” says Steiner.
Ice on the retreat
Andreas Kellerer-Pirklbauer from the Department of Geography and Regional Science is investigating the effects of climate change on glaciers and permafrost in the Alpine region. These include, among other things, block glaciers, mixtures of debris and ice that slowly move downhill. The more the rock glacier warms up, the more liquid water is present in the system, which increases the rock glacer velocity (RGV). “In the European Alps, 2023-2024 was the second warmest hydrological year since weather records began. A hydrological year begins on 1 October and ends on 30 September of the following year. The rise in temperature led to a general increase in block glacier movement. Compared to the previous year, the RGV increased by 80 per cent in the Swiss Alps, 17 per cent in the French Alps and around five per cent in the Austrian Alps,” reports Kellerer-Pirklbauer. These changes are consistent with the rise in permafrost temperature.
On a global scale, a general increase in rock glacier dynamics has been observed since the 1950s. “In the Andes in South America, RGVs remained high in 2023-2024, with values similar to those of previous years. Movement data in the United States and Central Asia confirm the general trend of increased block glacier dynamics in the recent past,” says the researcher. “This development, which is linked to anthropogenic climate change, shows us once again that we must intensify our efforts in climate protection,” emphasises Kellerer-Pirklbauer.
