New Delhi, Feb 3 (PTI) Yearly carbon emissions from lakes in the Qingzang Plateau (QZP) or the Tibetan Plateau have declined with some lakes shifting from being carbon sources during 1970-2000 to becoming carbon sinks in the next two decades, new research has found.

Researchers said the trend of decreasing carbon emissions in QZP lakes over the past five decades suggested that these lakes could assume an increasingly significant role in both regional and global carbon cycles in the context of ongoing global climate change.

Also Read | People Will Suffer Under Modi Government if Rahul Gandhi's Struggle To Save Democracy Fails, Says Mallikarjun Kharge.

The Qingzang Plateau, known as the Himalayan Plateau in India, is a vast elevated plateau located at the intersection of Central, South and East Asia and includes the Indian regions of Ladakh and Lahaul and Spiti.

While carbon sources release more carbon into the atmosphere than they absorb, carbon sinks absorb more carbon from the atmosphere than they release.

Also Read | PM Narendra Modi Arrives in Assam on Two-Day Trip; To Unveil Development Projects Worth Rs 11,600 Crore on February 4.

The researchers, including those from the Chinese Academy of Sciences, China, said their study offers insights into the timing and degree of shifting in the yearly carbon dioxide (CO2) exchange flux for lakes in the QZP region. Their findings are published in the journal Environmental Science and Ecotechnology.

The team found that between 1970 and 2000, the lake systems in the QZP had generally acted as carbon sources. However, from 2000 to 2020, some freshwater and saltwater lakes shifted from acting as carbon sources to small carbon sinks, with decreasing yearly CO2 exchange flux.

They also found that before 2000, the average temperature on the QZP from 1970 to 2000 was lower, aquatic plant and phytoplankton rates were relatively low, and the effect of respiration on carbon emissions was more pronounced.

After 2000, however, the average temperature on the QZP was seen to show a rising trend.

Further, the researchers found that the CO2 absorbed through photosynthesis exceeded the CO2 released through respiration, along with a reduction in the partial pressure of CO2 (pCO2) at the water-air interface and water bodies became increasingly less saturated. All of these conditions were conducive for CO2 entering water bodies, they said.

They found that in recent decades, the yearly solar radiation on the QZP has generally declined. This will weaken the circulation of warm and cold water in the water bodies, known to cause a significant outflow of CO2, and therefore reduce CO2 emissions, they said.

Phytoplankton and aquatic macrophytes, too, are sensitive to light and a slight reduction will slow respiration processes and gradually decrease CO2 emissions, they said.

(The above story is verified and authored by Press Trust of India (PTI) staff. PTI, India’s premier news agency, employs more than 400 journalists and 500 stringers to cover almost every district and small town in India.. The views appearing in the above post do not reflect the opinions of LatestLY)