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Abstract
Excess release of
carbon in the form of greenhouse gases is a major cause of global warming and
climate change. Carbon dioxide (CO2), methane (CH4),
and nitrous oxide (N2O) are considered prominent greenhouse gases
that trigger the problem of global warming. The global warming potential of
methane and nitrous oxide is several-fold higher than CO2, but
generally, when we discuss global warming and climate change, we only think
about carbon emission in the form of CO2 and neglect the
contribution of CH4 and N2O. According to the recent
data of the Keeling Curve, which continuously measures the concentration of
atmospheric CO2, it gradually increases with time, exceeding
>425 ppm, which is severely higher than the preindustrial era. The impact
of climate change is visible in different forms, including polar ice melting,
rising sea levels, and excess precipitation and flood in some areas, while
shorter winters, longer summers and droughts in other areas. Changes in the
life cycle of plants and migratory behaviour of birds, biodiversity loss,
ocean acidification, and disturbed biogeochemical cycling of materials are
some other visible impacts of climate change. Intergovernmental Panel on
Climate Change (IPCC) has decided to check the average global temperature
increase up to 1.5°C from the preindustrial era by the end of this century to
reduce the deleterious effects of climate change, but it is believed that if
all the signatory states follow the strict norms it unavoidable and we have
to develop right mitigation, adaptation and resilience strategy to cope with
climate change issues. The Government of India launched its National Action
Plan on Climate Change (N.A.P.C.C.), including 8-different missions, on 30
June 2008. Under the National Mission on Strategic Knowledge for Climate
Change (NMSKCC), India updated its Nationally Determined Contributions (NDCs)
in August 2022 and committed to achieve the goal of net-zero carbon emissions
by 2070 in the United Nations Framework Convention on Climate Change (UNFCCC)
meeting (COP-27) in November 2022. The aim of The National Mission on
Strategic Knowledge for Climate Change (NMSKCC), implemented by DST, is to
promote research, knowledge generation, and capacity building related to
climate science
Understanding
the cause-effect relationship is a prerequisite to eradicate or mitigate the
problems. In this case, understanding the source and sink relationship of the
emitted carbon footprint is essential. The burning of fossil fuels for
industrial transport and electricity generation is one of the biggest sources
of environmental carbon. In addition to CO2, methane is another
potent greenhouse gas with 28 times more greenhouse potential on a 100-year
scale. Anaerobic degradation of waste at open garbage dumping sites
(Landfills) by methanogenic archaea and biomethanation activity in
waterlogged rice paddies and wetlands is a prominent source of environmental
methane and contributes substantially to the problem of climate change. In
addition to methane and carbon dioxide, nitrous oxide, a by-product of
denitrification pathway, is another biggest contributor to global warming.
Soil fertilization induces release of nitrous oxide in the environment.
Similarly, wetlands and wastewater treatment plants also contribute
substantial amount of nitrous oxide release into the environment. According
to a recent estimate, wastewater treatment plants release an aviation
industry-equivalent amount of carbon into the environment in the form of CO2,
CH4 and N2O. In addition, Cement and Steel industries
emit substantial amounts of carbon in the form of CO2.These are
some prominent sources of environmental carbon footprintsthat are responsible
for greenhouse effects, global warming, and related climate change. In
contrast to different carbon sources of the environment, soil, wetlands,
oceans, and forests serve as major natural sinks (ecological footprint) for
carbon and play important roles in carbon sequestration. Furthermore, the
majority of the population thinks that burning fossil fuels and vehicular
carbon emission is the only source of environmental carbon, neglecting other
potent sources of methane and nitrous oxide. Emissions from livestock,
agricultural practices, wastewater treatment plants, open waste degradation
at garbage dumping sites, wetlands, rice paddies, and ruminants are also
substantially contributing to the problem of warming and climate change, which
needs due attention. On most of the platforms, we mainly discussed about
capture and release of carbon in the form of CO2 and neglect other
potent source of grren house gases like CH4 and N2O, which
constitute a substantial portion of the environmental carbon footprint. We
have to think about it and start developing a mitigation model and capture
strategies for them.
India
is an agricultural-rich nation, and agricultural practices release
substantial carbon into the environment and produce biomass in surplus
amount. Minimal attention has been paid on soil conservation, mitigation of
excess fertilization, methane mitigation from rice paddies, and burning and
degradation of agrobiomass in the open, either in the field or at garbage
dumping sites. Implementation of sustainable agriculture practices at the
community level and promotion of the development of biomass-based fuels like
bioethanol and biogas definitely contribute to carbon mitigation practices of
the nation.
Despite
being one of the main sources of global carbon emission and a cheap way of
municipal solid waste management, limited attention has been given to
landfills and their impact on urban warming, climate change, and their
relation to public health. The practices of degradation of waste at open
garbage dumping sites should be restricted and sanitary landfills with
leachate and gas collection systems should br developed. Collected methane
can be upgraded and used as high-quality biofuel. The development of sanitary
landfills with methane and leachate collection systems is a current need in
India. It prevents the spread of infection in the nearby communities as well
as captured biogas can be upgraded into bio-CNG using the potential of
hydrogenotrophic methanogens, which is another prominent area of energy
research for India because, along with carbon capture and mitigation, it will
provide high-quality biogas for fuel purposes. Thus, it is clear that
non-judicious or non-sustainable practices of agriculture, garbage
management, urbanisation, and wastewater treatment are responsible for
emerging climate risks and we have to expand and preserve the ecological
footprint for better carbon sequestration and climate risk mitigation.
Sustainable CO2 capture technology should be developed to mitigate released
carbon and convert it into another valuable resource like biogas or methanol.
In addition, thinking about clean energy, solar panel wind and carbon capture
from the cement and steel industry, funding agencies should also divert their
attention on various ways to mitigate or use methane and nitrous oxide
release from wastewater treatment plants, ruminants, agriculture practices
and other sources. Experts should develop efficient mitigation and capture
models for better results. In addition, soil preservation, wetlands
maintenance and conservation, and conservation of grasslands and forests
should be promoted to increase the natural carbon sink or ecological
footprint of nature. The promotion of methanogenesis and
methanotrophy-related research can play a crucial role in the development of
carbon capture and climate risk mitigation strategies in future.
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