In January 2025, the Alternative for Germany (AfD) published an election manifesto on their official website where they had this claim on page 77: “[…] CO₂ has proven to be a driver of increased plant growth, thereby supporting global nutrition”. This claim is mostly false.
The AfD is a right-wing populist party in Germany that is known for its critical stance towards the European Union and immigration policies. It also holds firm views on climate change and the transition to renewable energies. The AfD currently holds 151 seats in the German Bundestag. This represents 23,97 % of all seats. After the EU election, the AfD and other far-right parties from several countries formed the new group “Europe of Sovereign Nations” (ESN), which includes 25 members from eight countries and is dominated by the AfD.
AfD sources check
After multiple attempts to contact the AfD for their sources went unanswered, we reviewed one of the party’s blog posts ourselves. The article in question is titled “CO₂ not a curse, but a blessing” and it was published by the AfD in Schleswig-Holstein. In it, the party claims that carbon dioxide is beneficial to the planet and food production. To support this argument, the post indirectly refers to a 2016 study published in Nature Climate Change. The study found that part of the global “greening” effect can be attributed to rising atmospheric CO₂ levels (for example the increase in vegetation over recent decades). However, the AfD presents the study in a highly simplified manner. The authors of the original research clearly state that CO₂ is only one of several contributing factors (alongside nitrogen deposition, land use change, and climate variability). They also caution that the long-term consequences of greening are uncertain and that their findings should not be misinterpreted as evidence that CO₂ is beneficial overall or harmless to the climate.
As Prof. Dr. Sabine Fuss, Head of Research at the Mercator Research Institute on Global Commons and Climate Change, notes: “An increasing CO₂ concentration can indeed stimulate plant growth, but it also reduces the nutritional value of most food crops. Additionally, the climate change associated with higher CO₂ levels brings further negative impacts on food crops, whether through altered precipitation patterns or higher temperatures.”
The blog post also links to content that is hosted by the European Institute for Climate and Energy (EIKE), a climate-sceptic organization, whose views align with the AfD’s argument. However, EIKE is not a scientific institution but a private association. Its spokesperson, Horst-Joachim Lüdecke, has publicly stated, “we don’t need climate scientists,” and rejects the idea that CO₂ contributes to global warming.
The AfD also cites articles from the U.S.-based group CFACT and statements from its own “Committee for Energy Policy, Climate Change, and Digitalization”. These sources are either partisan or unverifiable, raising questions about their credibility and independence.
Nutrients
Scientists have found that when there is more carbon dioxide (CO₂) in the air, plants do not just grow faster — they actually grow differently. For example, they may develop fewer nutrients, or their leaves and grains might become larger but contain less of the essential nutrients we need. These changes affect how plants grow and what they provide to humans.
Some components in plants, such as sugars or starches, may increase under higher CO₂ levels. While sugar is important for energy, the bigger concern is that key nutrients — like protein, iron, and zinc — might go down. These are vital for human health, especially in regions where people rely heavily on staple crops like rice, wheat, or corn.
In a study published in Nature in 2014, Dr. Samuel Myers of Harvard University and his team showed that crops grown with elevated CO₂ levels — similar to what is expected by the year 2050 — had:
- 8% less protein
- 5–10% less iron
- 3–12% less zinc
“Some things in plants go up when CO₂ goes up, but important nutrients like iron, zinc, and protein go down. That is a big problem for people’s health around the world,” says Dr. Myers.
Another large study in 2018 confirmed these findings: food grown with more CO₂ is less nutritious. A 2024 study added a new concern — rising CO₂ also affects pollen, which bees and other pollinators rely on. The study showed that higher CO₂ levels change the composition of pollen, which could hurt pollinator health and survival. This means the effects are not just about humans — the entire food chain could be impacted. According to the World Food Summit, food security means that all people, at all times, have physical and economic access to sufficient, safe, and nutritious food that meets their dietary needs and food preferences for an active and healthy life.
Food security includes four key dimensions:
- Availability – enough food must be produced.
- Access – people must be able to obtain it.
- Utilization – food must be nutritious and properly used by the body.
- Stability – these first three must be reliable over time.
Rising CO₂ threatens multiple dimensions of food security. It reduces utilization by lowering nutritional quality, and may harm availability by affecting pollinators and crop health. If these issues get worse over time, stability is also at risk.
Picture of a bee covered in pollen on a flower. Photo by Michael Reichelt, Pixabay.
Statistics
Atmospheric carbon dioxide levels were recorded at Mauna Loa Observatory in Hawaii. This graph shows the station’s monthly average carbon dioxide measurements since 2000 in parts per million (ppm).
CO₂ levels, one of the most important human-caused greenhouse gases, are constantly growing worldwide. The average 12-month level of CO₂ in 2000 was 368.63 parts per million (ppm); in 2021, it was already 414.57 ppm; in March 2025, it went up to 425.37 ppm. Carbon dioxide levels have increased by approximately 15.4% over the past 25 years. The Food and Agriculture Organization of the United Nations posted research on agricultural production statistics from 2000 to 2021. It indeed shows that agricultural production is constantly growing, like CO₂ levels. In 2021, there were 44.2% more fruits than at the beginning of the century. Cereal grew by 51.4%, and vegetables are the leader: 65.5%
FAOSTAT: Production Quantity of top cereals.https://www.fao.org/faostat/en/#data/QCL
FAOSTAT: Production Quantity of vegetables and fruits.
Carbon dioxide (CO₂) is essential for photosynthesis. But CO₂ also makes the growing season longer, allowing to produce more plants. Thelength of the growing season in the U.S. has increased by more than two weeks since the beginning of the 20th century. Therefore, it allows more plants to grow.
Illustrative image showing drought. Photo by Tom D’Arby, Canva.
Land degradation – and its effect on food security
According to the IPCC’s special report about climate change and land, CO₂ emissions alongside other greenhouse gases are linked to climate change and soil degradation.
Soil degradation includes erosion, desertification, drying, and loss of fertility. As a result, soil productivity declines, threatening food security, especially in vulnerable regions. Managing land becomes more difficult, and people living in degraded areas face increased inequality due to climate change. These factors also affect plant health and nutrient content.
“Studies assessed find that climate change will increasingly be detrimental to crop productivity as levels of warming progress. Impacts will vary depending on CO₂ concentrations, fertility levels, and region.” (IPCC, Chapter 5).
Extreme weather and worsening conditions make food production more challenging. Although CO₂ may temporarily stimulate plant growth, it ultimately undermines food security over the long term. It is also important to consider the economic dimension of food security. “Climate change negatively affects all four pillars of food security: availability, access, utilisation and stability.” (IPCC, Chapter 5)
Other negative effects of climate change on plants
Even though CO₂ can temporarily stimulate plant growth under controlled conditions, major scientific organizations such as the IPCC and the FAO emphasize that these effects are insufficient to outweigh the broader negative consequences of climate change on agriculture and therefore plant growth.
Rising temperatures place significant strain on plants, particularly during sensitive developmental stages such as flowering and fruiting. According to the Environmental Research Series, heat waves and extreme temperatures are already contributing to declining yields worldwide.
The IPCC warns that even a one-degree Celsius increase in temperature can lead to global yield losses in wheat, maize, and rice — staple foods for billions of people.
At the same time, water scarcity is intensifying. The IPCC shows that droughts, shifting rainfall patterns, and reduced soil moisture are negatively impacting agricultural production. Regions that already face limited water resources are at most risk. The FAO also projects long-term declines in irrigated agriculture, particularly in Africa and South Asia. Extreme weather events such as storms, floods, and hail are increasing due to climate change, which causes significant damage to agricultural land and crop yields. The FAO reports that storms are among the leading weather-related causes of crop losses, particularly in tropical and subtropical regions.
As Prof. Dr. Matin Qaim, Director of the Center for Development Research (ZEF) at the University of Bonn, summarizes: “When the different effects—namely climate change and CO₂ fertilization—are considered together, the negative impacts clearly outweigh the positive ones. In other words, a higher CO₂ concentration in the atmosphere has negative net effects on crop yields and global food security.”
Conclusion
In its 2025 election manifesto, Germany’s AfD party claimed that CO₂ boosts plant growth and supports global nutrition. While CO₂ can enhance photosynthesis, scientists have shown it also reduces crop nutritional quality and that it doesn’t offset climate-related harms like heat, drought, and extreme weather. All in all, the AfD’s argument oversimplifies a complex issue. It relies on reputable sources but overlooks key scientific findings. The AfD’s claim is misleading and mostly false because they use it as an argument for proving that climate change is fake.
RESEARCH | ARTICLE © Juliane Kegreiss, Hochschule der Medien, Stuttgart, Germany | Marija Jevdasina and Darius Korickij, Thomas More University of Applied Science, Mechelen, Belgium | Tommi Saranpää, Haaga-Helia University of Applied Sciences, Helsinki, Finland | Heike Jansen, HU University of Applied Sciences, Utrecht, Netherlands | Nike Tecklenborg and Sophie Hecker, Jade University of Applied Sciences, Wilhelmshaven, Germany
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