ROLE OF CITY PARKS IN THE FIGHT AGAINST CLIMATE CHANGE

· SIGNIFICANT ROLE OF CITY PARKS IN CARBON SEQUESTRATION
· FINDINGS OF THE STUDY PUBLISHED IN INTERNATIONALLY REPUTED SCIENTIFIC JOURNAL “NATURE CLIMATE CHANGE”

A study by an international team of researchers including Dr. Jay Prakash Verma and his student Dr. Durgesh Kumar Jaiswal from Banaras Hindu University, has suggested that urban green areas, including parks and gardens, are a fundamental part of cities and are, on many occasions, the only contact that humans have with nature. These urban green spaces provide us with a myriad of ecosystem services, from training our immune system and promoting physical and mental health to regulating heat waves and floods, which are especially important in the current context of urbanization. Dr. Verma is working as Senior Assistant Professor at the Institute of Environment and Sustainable Development in Banaras Hindu University. Dr. Durgesh Kumar Jaiswal has completed his Ph.D. under the supervision of Dr. Verma.

These urban green spaces play an important role in global carbon sequestration, a vital ecosystem service for mitigating CO2 emissions and the effects of climate change. The carbon stored in our parks also contributes to the maintenance of soil biodiversity and facilitates the sustainability of our parks, which means less expenditure for the public coffers. Until now, the quantity, controlling factors and sensitivity of carbon to global warming in urban green areas had not been evaluated, which meant considerable uncertainty in future predictions about the magnitude of carbon sequestration in these ecosystems.

This research includes samples from 56 cities across all continents. The research highlights the fundamental role of urban green spaces as carbon reservoirs: Dr. Jay Prakash Verma said “Our study shows that urban parks in green spaces around the world have an equivalent amount of carbon in the soil to natural areas near our cities, highlighting the role of our parks in a context of climate change”. Furthermore, the research highlights that the carbon stored in natural areas and urban parks are controlled by similar climatic factors. “Warmer cities have lower soil carbon content in urban parks and natural ecosystems, which is not good in our fight against climate change in a warmer world,” says Dr. J.P. Verma

The study also shows that carbon in cities and natural areas are regulated by different biological factors. The carbon of natural areas is closely related to the primary productivity of the ecosystem, while soil microbes are particularly important in explaining the carbon of parks and gardens. In this framework, ecosystem management (e.g. mowing) plays a fundamental role in explaining carbon sequestration in urban green spaces: “In natural ecosystems, primary productivity and decomposition of organic matter define carbon input, but this relationship may be perturbed by the management of plant communities in urban systems. Our study demonstrates that soil microbes are the main drivers of carbon in urban areas.

Finally, the research suggests that the importance of microbes as carbon regulators in urban parks is a double-edged sword. “Carbon in park and garden soils is more vulnerable to loss through microbial respiration in response to global warming” says Dr. J.P. Verma. “These soils have a high proportion of genes associated with the decomposition and mineralization of organic matter”. “Our study demonstrates the importance of parks as carbon reservoirs in an urbanized world, where 7 out of 10 people will live in cities by 2050. Future parks and urban policies should take into account the soil microbiome to maintain soil carbon and its capacity to maintain multiple ecosystem services as well as the sustainability of our parks” concludes Dr. Verma.

This study has been carried out as part of the URBANFUN project of the BBVA Foundation awarded to Dr. Manuel Delgado-Baquerizo and other twenty institutions from different countries have participated in the project including India.

The findings of the study have been published in internationally reputed scientific journal “Nature Climate Change”. Banaras Hindu University’s contribution to this research was funded by Department of Science and technology (DST), Science & Engineering Research Board (SERB), Govt. of India, and Institution of Eminence Initiative, Banaras Hindu University.