China's Terrestrial Ecosystems Play Key Role in Carbon Sink: Research

China's terrestrial ecosystems, including forests, shrubs and farmlands, have played an important role in storing carbon emissions over the past decades, Chinese research has shown.

A study, published in the Proceedings of the National Academy of Sciences (PNAS) of the United States on Wednesday, found that China's forests, shrubs and croplands sequestrated 201.1 million tonnes of carbon every year from 2001 to 2010, which offset 14.1 percent of the carbon emissions from burning fossil fuels in China during the same period.

China's forests are the major carbon sinks, contributing 80 percent of the carbon storage by terrestrial ecosystems, while the croplands and shrub lands make up 12 percent and 8 percent respectively, the research showed.

"These carbon stock changes are largely attributed to climate change, ecological restoration projects and cropland management," said Fang Jingyun, lead scientist of the research and an academician of the Chinese Academy of Sciences (CAS).

In particular, China's six major ecological restoration schemes the Natural Forest Protection Project, the Shelter Forest Program in northern, northeastern and northwestern China, the Grain for Green Program, the Returning Grazing Land to Grassland Project, the Yangtze River and Zhujiang River Shelter Forest Projects and the Beijing-Tianjin Sand Source Control Project - have contributed 36.8 percent of the total carbon sequestration by terrestrial ecosystems, Fang said.

Reviewers of PNAS commented that the study is important because it demonstrates how ecosystem restoration can play a substantial role in climate change mitigation.

"The decade from 2001 to 2010 was a period when China made a rapid economic development. It's a remarkable achievement that China's terrestrial ecosystems could offset 14.1 percent of the carbon emissions from burning fossil fuels," Fang said.

Yu Guirui, deputy director of the Institute of Geographic Sciences and Natural Resources Research of the CAS, said the research shows that China has great potential in carbon sequestration.

"Previously people were not sure whether we could mitigate climate warming by artificial means. China has implemented so many ecological programs, which were originally for the purpose of ecological protection. But our research demonstrates that those projects also play an important role in carbon sink," Yu said.

"In our previous study, we also found the phenomenon of carbon increase in farmlands in some regions. But we lacked comprehensive data. Through this research we are now confident that China's advancement in agriculture management not only guarantees grain production but also contributes to carbon sequestration."

Yu called on the government to continue to support basic investigation and research to get a clearer understanding of China's carbon sinks.
Climate change is one of the biggest challenges facing humanity. The Paris Agreement, which took effect on November 4, 2016, became the second legally binding climate agreement after the Kyoto Protocol, and coordinates global efforts to combat climate change.

As a party to the Paris Agreement and the largest developing country, China has implemented a strategic plan to adjust economic development models and promote technological progress in energy conservation and emissions reduction. This strategy has led to remarkable achievements in reducing energy consumption and greenhouse gas emissions.

However, with rapid economic development, China is facing growing pressure to further reduce energy consumption and greenhouse gas emissions.

Carbon sequestration by terrestrial ecosystems is one of the most economically and environmentally friendly ways to mitigate atmospheric CO2 concentrations, said Fang.

"How to improve the carbon storage and carbon sequestration of terrestrial ecosystems is not only a cutting-edge field of global change research, but also the key scientific foundation for the mitigation of climate change," Fang said.

To this end, the CAS initiated a five-year strategic priority research program, "Climate Change: Carbon Budget and Relevant Issues", in January 2011. Under the program, a research team was set up to study the impacts of climate change and human activities on the structure and functioning of ecosystems, with an emphasis on quantifying the magnitude and distribution of ecosystem carbon pools and sequestration in China's terrestrial ecosystems.

From 2011 to 2015, the team of more than 350 researchers conducted a nationwide field survey of vegetation, soils and habitats in China's terrestrial ecosystem, including forests, grasslands, shrubs and farmlands.

The research demonstrated that climate and land-use changes have profoundly altered the structures and functions of China's terrestrial ecosystems and their carbon storage. Restoration regimes and agricultural management practices that integrate economic and policy incentives were particularly effective in facilitating ecosystem carbon sequestration, Fang said.

"These findings provide new insights into the role of human intervention in facilitating ecosystem carbon storage, and offer useful lessons to other developing countries that are experiencing similar economic and social transformations," Fang said. (Xinhua)

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