The scientists analyzed greenhouse gas emissions from over 1000 wastewater treatment plants in China from 2009 to 2016. They found that these plants released more greenhouse gases over time, mainly due to electricity use. Each plant's efficiency varied, with some needing improvements in electricity consumption and ammonia reduction to be more eco-friendly. Plants using a specific treatment process and having certain characteristics emitted fewer gases. The study suggests ways to help these plants reduce emissions and reach carbon neutrality, which is essential for fighting climate change.