Climate change in the Duchy of Lauenburg – „We have had historic weather events in recent years, and that in a very short period of time“.
The climate in the Duchy of Lauenburg County is moderate. The average temperatures are around zero degrees in winter and just under 20 degrees during the summer. In addition, it rains more than average in the region: there are usually about 13 rainy days in July. However, the consequences of climate change have been increasingly felt in the Duchy of Lauenburg County for some years.
Not only have short-term weather fluctuations increased, so that, for example, temperature jumps of 10 degrees occur within a few days, but there are also more frequent heavy rain events and milder winters. „We have had historic weather events in recent years, and that in a very short period of time,“ says Corina Müller, the district’s climate protection manager, who is inter alia responsible for the development and implementation of the region´s climate protection roadmap. While there was above-average rainfall in 2017, especially in the summer, 2018 was the hottest summer in northern Germany since weather records began. In addition, the river Elbe experienced floods of the century in 2002 and 2013, which were triggered by rainfall that had previously lasted for days.
How drought can occur in the region despite increased heavy rainfall events can be explained by „poorer distribution of precipitation“. This is because the dry phases become longer and at the same time the precipitation is concentrated at individual times when there is such heavy rainfall that the soils cannot absorb these amounts of water quick enough. Flooding and soil erosion are the result.
More than half of Duchy of Lauenburg County consists of agricultural land. However, hardly any economic sector is as dependent on the climate as agriculture, therefore extreme weather events are particularly noticeable here. Above all, the scarcity of water due to the decrease in summer precipitation in recent years is a huge concern for the region’s farmers. The lack of rain leads to a drying out of the soils down to deep soil layers and to a lowering of the groundwater level.
Meteorological shifts are also causing changes in vegetation. For example, the more frequent mild winters affect rapeseed, barley, and wheat. This is because a certain cold stimulus promotes the growth of these plants the next spring and a snow cover protects the winter crops. In addition, temperatures below zero degrees loosen the soil so that the soil structure is improved, and various pests do not survive these frosty temperatures.
Agriculture, however, is not only affected by climate change, but is also a contributor: the use of fertilizers, for example, has a major influence on the climate and surrounding ecosystems. „A distinction is made between organic and mineral fertilizers. Organic fertilizers accumulate on the farm; these are, for example, liquid manure or fermentation residues from the biogas plant. If too much fertilizer is applied to the fields, there is a risk of nutrients leaching out, which can lead to water pollution. In addition, nitrous oxide and methane emissions are produced when organic fertilizers are applied,“ explains Corina Müller. Methane is 25 times more harmful to the climate than CO2, and nitrous oxide is almost 300 times more harmful.
Mineral fertilizers, on the other hand, are produced in a very energy-intensive chemical process and thus have a huge impact on the climate. The ammonia synthesis used for production is even one of the largest industrial energy consumers – it accounts for about one to three per cent of the global energy demand.
According to Müller, the development of climate-friendly agriculture is extremely important – paying attention to short transport routes, soil-promoting and seasonal crop rotation and fair business and trade relations with a regional value chain. But she also sees another field of action: „In addition to the reduction of greenhouse gases in agriculture, the climate protection concept of our district also focuses on the creation of CO2 sinks in the form of humus build-up.“ Soil is one of the largest CO2 reservoirs: Worldwide, they remove 150 to 250 million tons of CO2 from the atmosphere every year. Humus plays a special role here; it is composed of dead plant and animal matter and consists of more than 50 percent of carbon. Furthermore, it has an important function in the ecosystem, it can store up to 20 times its own weight in water and protects the soil from erosion.
The Duchy Lauenburg County is dealing with the question of how to achieve an agriculture that is both better adapted to climate change and itself produces fewer greenhouse gases in the EU project „KNOWING“, which conducts research on climate impact adaptation and climate protection strategies. „For about 1,000 hectares of county-owned individual leased land, the leases are to be renewed in 2027. We hope that the project will provide us with input on climate-friendly agriculture and criteria that we can include in the new lease agreements,“ says the climate protection expert.
