Grasslands turning from carbon sinks to emitters

Grazing livestock is increasing carbon emissions from grasslands.

Fremont, CA: The grasslands, known for their cooling effect on the climate, are becoming climate warmers, as a result of increasing greenhouse gas emissions. The study was published in Nature Communication which showed that emissions from grasslands have increased by a factor of 2.5 since the 1750s, and it is mainly due to grazing livestock. This phenomenon is limited to areas that are not managed by humans and are sparsely grazed.

Grasslands account for 26 percent of the world's landmass and 70 percent of the world's farming area. It provides job opportunities to more than 800 million people and they are a crucial source for livestock and habitat for wildlife. It offers environmental protection, water conservation, and plant genetic resources.Greenhouse gases such as carbon dioxide, methane, and nitrous oxide are involved in the grassland ecosystem.Still, very little is known about the fluctuations that these three greenhouse gases have in their concentration that affects climate change. 

The net carbon sinking ability of the grasslands was estimated to have increased in the last century, but it was mainly due to over sparsely grazed and natural grasslands.

Over the last decade, grasslands were managed by humans and have become an exclusive source of greenhouse gas emissions. Eastern and Southern China, along with India have large greenhouse gas sources (managed grasslands) due to high livestock density. The study highlights that cooling services provided by sparsely grazed and wild grasslands indicate that countries need to assess the greenhouse gas budget and manage their pastures, which is extremely important to meet the Paris Climate Agreement targets. The key takeaway from the study is that grasslands can help fight against the climate crisis by storing carbon in the soil, which is why conservation of grasslands should be included in the strategy to reduce climate change.