The ESS Guide (2024) states that " Human activities, such as burning fossil fuels, deforestation, urbanization and agriculture, have impacts on flows of energy and transfers of matter in ecosystems." 

The guidance states that " Although burning fossil fuels may lead to increased CO₂ available for photosynthesis, the other pollutants and impacts of global warming will reduce primary productivity. Deforestation, urbanization and agriculture all lead to loss of ecosystem biomass, disruption of food webs, and the capacity for photosynthesis."

Our Ebook 2.2: Energy and Biomass in Ecosystems  expands on this:

Increased CO₂: 

Burning fossil fuels releases carbon dioxide (CO₂) into the atmosphere. While CO₂ is a greenhouse gas, it's also a raw material for photosynthesis in plants. In theory, increased CO₂ could potentially lead to increased primary productivity (plant growth).  Each year, human activities release more carbon dioxide into the atmosphere than natural processes can remove, causing the amount of carbon dioxide in the atmosphere to increase. The global average carbon dioxide set a new record high in 2022: 417.06 parts per million.

Deforestation, Urbanization, and Agriculture:

• Loss of Biomass: These activities all contribute to the loss of trees and other vegetation. This reduces the overall biomass (total amount of living organic matter) within the ecosystem.
• Food Web Disruption: Loss of vegetation disrupts food webs as herbivores lose their food source, impacting predator populations that rely on them.
• Reduced Photosynthesis: Fewer plants mean less overall photosynthetic activity, leading to a decrease in primary productivity and the amount of energy entering the ecosystem.

Overall Impact:

• Human activities like those mentioned disrupt the natural balance within ecosystems. While there may be some initial short-term benefits, the long-term consequences are often detrimental.

• Reduced Ecosystem Services: Healthy ecosystems provide us with essential services like clean air and water, food production, and climate regulation. The disruptions caused by human activities jeopardise these services.
• Loss of Biodiversity: Reduced plant growth and habitat loss can lead to declines in animal populations and biodiversity loss.
• Cascading Effects: The disruption of energy flow and matter transfer in one part of the ecosystem can have cascading effects throughout the entire system, impacting all trophic levels (feeding levels).