Inland Waters Overlooked as Major Source of Greenhouse Gas Emissions: Scientists Warn

Inland waters, including rivers, lakes, streams, and wetlands, are natural habitats for various aquatic species. They also serve as oases of water resources used not only by animals but also by local communities. For the longest time, these bodies of water have become a part of the environment and biodiversity, ranging from the largest animals down to the smallest microorganisms. However, scientists found recently these waters have a downside.

A study published in February 2024 confirms that inland waters are also great emitters of greenhouse gases; which travel into the atmosphere, eventually contributing to the global carbon cycle. Researchers involved in the study explored carbon emissions from inland bodies of water in China. Due to its vast land area, the East Asian country has a large number of natural and artificial inland waters, according to the recent research paper.

Greenhouse Gas Emissions

In the context of climate change, the anthropogenic emissions of greenhouse gases are the leading cause of temperature rise worldwide. The atmospheric and oceanic warming of Earth means weather patterns will continue to be altered and towering glaciers to melt. This is mainly caused by the natural process of the greenhouse effect, where greenhouse gases are trapped in the atmosphere and absorb the Sun's heat.

In previous studies, climate-damaging gases such as carbon dioxide and methane are often traced from various industrial sectors. Yet, there is little attention to the contribution of rivers, lakes, and other inland waters to the greenhouse effect. In the United States, burning fossil fuels for electricity, heat, and transportation is the largest source of greenhouse gas emissions, according to the U.S. Environmental Protection Agency (EPA).

Chinese Inland Waters

In the paper published in the Journal of Geophysical Research: Biogeosciences on February 24, researchers from China conclude that inland waters are important sources of greenhouse gases but affect the Earth's carbon balance. The research team focuses Chinese inland waters where dissolved carbon dioxide and methane emissions are disturbed by both human activities and global climate change.

Selecting China as a focus of their study, the team also noted that China experienced unprecedented environmental changes due to the nation's rapid economic development as seen in previous decades. However, this development is parallel with the modification of the country's inland water carbon biogeochemistry and related emissions. Furthermore, the large territory of China, with its widespread water systems, amplifies the emissions.

Regardless of the recent findings on inland waters, human-induced greenhouse gas emissions from different industries remain a threat compared to these bodies of water. According to the International Energy Agency (IEA), global carbon dioxide emissions increased by 0.9% in 2022 to a record-breaking 36.8 gigatons.

With this, carbon has become one of the target greenhouse gases by multiple nations to address the issue of climate change. Excluding China, other countries (with emerging markets and developing economies) in Asia also saw a significant increase in emissions by 4.2% in 2022, the IEA reported.