Study: CO2 Emissions From Dry Inland Waters Much Higher Than Thought

by Ufz, Mau 1, 2020 in ClimateChangeDispatch


Inland waters such as rivers, lakes, and reservoirs play an important role in the global carbon cycle.

Calculations that scale up the carbon dioxide emissions from land and water surface areas do not take account of inland waters that dry out intermittently.

This means that the actual emissions from inland waters have been significantly underestimated—as shown by the results of a recent international research project led by scientists at the Helmholtz Centre for Environmental Research (UFZ) in Magdeburg and the Catalan Institute for Water Research (ICRA).

The study was published in Nature Communications.

 

 

“The interaction of local conditions like temperature, moisture, and the organic matter content of the sediments is crucial, and it has a bigger influence than regional climate conditions,” Keller explains.

So what do the results of the study mean for the future assessment of carbon dioxide emissions from inland waters? “Our study shows that carbon dioxide emissions from inland waters have been significantly underestimated up until now,” says Koschorreck.

Chinese Scientists: It Was Warmer In China During Medieval Warm Period Than Today

by Hao et al. , January  2, 2020  in GWPF


For China as a whole, the longest warm period during the last 2000 years occurred in the 10th–13th centuries’

Abstract: The Medieval Climate Anomaly (MCA, AD950-1250) is the most recent warm period lasting for several hundred years and is regarded as a reference scenario when studying the impact of and adaptation to global and regional warming. In this study, we investigated the characteristics of temperature variations on decadal-centennial scales during the MCA for four regions (Northeast, Northwest, Central-east, and Tibetan Plateau) in China, based on high-resolution temperature reconstructions and related warm-cold records from historical documents. The ensemble empirical mode decomposition method is used to analyze the time series. The results showed that for China as a whole, the longest warm period during the last 2000 years occurred in the 10th–13th centuries, although there were multi-decadal cold intervals in the middle to late 12th century. However, in the beginning and ending decades, warm peaks and phases on the decadal scale of the MCA for different regions were not consistent with each other. On the inter-decadal scale, regional temperature variations were similar from 950 to 1130; moreover, their amplitudes became smaller, and the phases did not agree well from 1130 to 1250. On the multi-decadal to centennial scale, all four regions began to warm in the early 10th century and experienced two cold intervals during the MCA. However, the Northwest and Central-east China were in step with each other while the warm periods in the Northeast China and Tibetan Plateau ended about 40–50 years earlier. On the multi-centennial scale, the mean temperature difference between the MCA and Little Ice Age was significant in Northeast and Central-east China but not in the Northwest China and Tibetan Plateau. Compared to the mean temperature of the 20th century, a comparable warmth in the MCA was found in the Central-east China, but there was a little cooling in Northeast China; meanwhile, there were significantly lower temperatures in Northwest China and Tibetan Plateau.