Impacts of geothermal power plants on air quality, climate change and biodiversity

Abstract

According to preliminary estimates, the Earth's system boundary related to atmosphere is being approached via aerosol loading. As of 1980, new ecological commodities have been discussed with the understanding that more natural is better within the scope of combating atmospheric stresses like air pollution and climate change. Probably, the most famous ones are from carbon programs based on green capitalism. The atmosphere is the sink while hosting a lot of varieties of gases emitted from diverse sources, and these precursors also cause new species from their reactions based on the compounds and their chemical structures. The fate of these species depends strongly on meteorological conditions. Understanding their fate and transport including complex processes with spatial and temporal varieties is vital to address societal concerns like air pollution, climate change, and significant environmental impacts. EPA Clean Air Act which is based on the existence to the success of the environmental movement defined six criteria air pollutants including SO2, O3, and NO2. WHO recommended limits for these pollutants along with the limits for H2S. Moreover, the standards were available for these pollutants by EU and Türkiye. Within the scope of adopting 1.5°C target decreasing CO2 emissions, the electricity production sector of global economies has profoundly transformed shifting from fossil fuels to renewable sources. One of the suggested and discussed renewable sources is geothermal energy. According to the latest statistics, Türkiye in 2024 has 1691 MW capacity of electricity production from geothermal technology. Türkiye is ranked 1st in European countries and 4th globally in terms of installed the capacity. Moreover, Türkiye is the 7th richest country globally in terms of geothermal energy potential. On the other hand, the sustainability and effectiveness of geothermal energy is a controversial topic in line with the decarbonization of energy systems. While geothermal energy is emphasized as a just transition and environmentally friendly energy policy in national plans, there are a lot of discussions regarding the negative impacts of GPPs, especially, depending on the geological characteristics of the area, used processes, and type of system. The NCG emissions from GPPs are amongst these discussions. As reactions against the effects of geothermal energy activities have increased over the years, environmental justice movements have also increased; fair and transparent processes have been demanded. GPPs in Aegean Region of Türkiye were located in sensitive areas according to environmental and social components. The agricultural products are amongst the most significant economic sources, especially for women. Negative impacts of gases from GPPs like H2S, CH4, and NH3 on air quality, climate change, and biodiversity have been previously discussed in the literature. Moreover, H2S might oxidize to SO2 air pollutant, CH4 might contribute to O3 formation, and NH3 might convert to secondary inorganic particulate matter having a driving force to climate change, therefore, impacting air quality and climate change.