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Environmental Challenges in the
Anthropocene
By: J. S. Singh
The Earth today is experiencing
environmental conditions which it has never experienced in the past. For
example, the CO2 concentration has varied between 180 to 280 ppm
during the past 420,000 years but it has now increased to 379 ppm. 40% of known
oil reserves have been exhausted by humans in the last 150 years that took
hundreds of million years to generate, 50% land surface has been transformed
affecting biodiversity, soil biology and climate, more nitrogen is fixed
synthetically for fertilizers than is fixed naturally, >50% of all accessible
freshwater is appropriated for human use and ground water resources are being
rapidly depleted, concentrations of climatically important gases have
substantially increased, coastal and marine habitats have been dramatically
altered; 50% mangroves have been removed and wetlands are reduced by one-half,
22% of recognised marine fisheries have been depleted and 44% are at their limit
of exploitation, and extinction rates have been increasing sharply. This
human-dominated era is therefore termed Anthropocene and is argued to have
started since 1850. It should be emphasized that Homo sapiens is not only
an invasive species capable of displacing all other species but is also a
keystone species having the capability of changing profoundly the surroundings.
This species appropriates more than 40% of the total terrestrial net production
of the Earth.
The anthropogenic activities,
to a great extent, are responsible for bringing about global climate change.
Predictions indicate that the average temperature of the Earth’s near surface
could increase by 5.8°C, and sea level may rise by an additional 88 cm by the
year 2100.
The total temperature increase from 1850 – 1899 to
2001 – 2005 is 0.76 [0.57 to 0.95]°C, and the rate of sea level rise was 1.8
mm/yr between 1961-2003, and 3.1 mm/yr between 1993-2003. For India,
predictions include: frequent dry days, 38% drop in per capita water
availability by 2050, 50 million people would be displaced in coastal area due
to sea level rise, by 2035 Himalayan glaciers may disappear and food grain
production may fall by 30%, vector borne diseases and those associated with
floods and droughts will increase, and 25% flora and fauna may be at a high risk
of disappearance by 2030. World-wide, 2.2 billion people living under moderate
or severe water stress will increase to 4 billion by 2025.The immediate task
with Indian scientists includes (i) assessing climate change effects through
systems and scenarios analysis, modeling, computer simulation, experimentation
and data integration, (ii) developing strategies and policy options for
adaptation with reference to food production, water resources, biodiversity and
human health, and studying and analyzing trade offs, e.g. 3,500 litres of
irrigation water will be needed for production of one litre of ethanol besides
diversion of acreage from grain crops to sugarcane.
Dependence of humans on forest
resources is high. 1.6. billion people rely heavily on tropical forest resources
for livelihoods, 1.2 billion people in developing countries use trees on farms
to generate food and cash, more than 2 billion people rely on biomass fuels
(mainly fuel wood), natural products from forests are the only source of
medicine for 75-90% of people in developing countries, thus one out of four of
the world’s poor depend directly or indirectly on forests for their livelihood.
However, 350 million ha of tropical forests have been deforested (0.8% per year)
and 500 million ha of secondary and primary forests have been degraded,
affecting the generation and flow of ecosystem services vital for human
well-being. More the poverty greater is the human dependence on forests, and
greater the dependence, greater is the stress on remaining forest. This calls
for sustainable forestry, which should include (i) harnessing the potential of
forests to reduce poverty, integrating forests into sustainable economic
development, and protecting local and global forest values.
Apart from deforestation, vast
areas (air, water and soil) have been altered and contaminated by industrial,
mining activities, and use of fertilizers/pesticides. This calls for development
of low cost technologies ( e.g. solar-powered pollutant removal systems) for
decontamination needed; in this respect phytoremediation using genetically
modified plants holds promise.
Biodiversity is the underpinning of
ecosystem services. These services include (i) provisioning Services- goods such
as food, fresh water, wood and fibre, (ii) regulating Services- disease control,
climate regulation, water purification, flood regulation, etc., (iii) cultural
Services- education, recreation, etc., and (iv) supporting Services- nutrient
cycling, soil formation, primary productivity, etc. 14 out of identified 24
services are now declining. According to one estimate, the current economic
value of the 17 ecological services for 16 biomes is in the range of US $ 16–54
trillion per year. Issues need to be investigated include (i) how do changes in
ecosystem structure and functioning affect delivery of ecosystem services?, (ii)
location, abundance, rates of renewal and resilience?, (iii) how is the delivery
of ecosystem services distributed across social groups ?, and (iv) how do people
respond to changes in ecosystem service provision?
Studies indicate that we have
entered into a phase of mass extinction; today we seem to be losing two to five
species per hour from tropical forests alone. This amounts to a loss of 16
million populations of various species per year or 1800 populations per hour.
This calls for concerted efforts at documenting species, their threat status and
conservation. This is specially relevant because between 1970 and 2003, the
Living Planet Index (biocapacity of the Earth) fell by about 30 per cent and as
of 2003 Ecological Footprint (area of biologically productive land or sea
required to produce food, material and energy) exceeded the Earth’s biocapacity
by 25%. Evidently, there is a need to reduce the ecological footprint through
sustainable development. Some of the possible actions required for reducing the
ecological footprint include (i) slowing population growth, (ii) reducing
consumption of goods & services, (iii) reducing footprint intensity, (iv)
extending bioproductive area, and increasing bioproductivity per ha.
Solutions for all of the above need
concerted research efforts.
Professor Emeritus,
Banaras Hindu University, Varanasi 221005, India, E-mail: [email protected] |
