2. TROPICAL, TEMPERATE AND POLAR
• BIODIVERSITY LOSS- HABITAT DESTRUCTION AND
EXTINCTION
• LAND AND SOIL- LAND DEGRADATION/WASTE
• WATER- HYDROLOGICAL CHANGES
• ATMOSPHERE AND CLIMATE- POLLUTION AND
CLIMATE CHANGE
• HUMAN HEALTH
3. RESOURCE CONSUMPTION
RESOURCE EXPLOITATION
EARTH
BIOSPHERE
PHYSICAL AND
BIOLOGICAL
RESOURCES
BIOCAPACITY
HUMAN
CIVILISATION-
ANTHROPOCENE
ECOLOGICAL
FOOTPRINT
GLOBAL
ISSUES/
PLANETARY
LIMITS
LOCAL
REGIONAL
GLOBAL
POPULATION
LAND USE
• TROPICAL
TECHNOLOGY
LAND USE
• TEMPERATE
FEEDBACK LOOP
LAND USE
• POLAR
4. BIODIVERSITY
• Biodiversity is the richness of biological variation—it exists at the levels
of genetics, species richness, and community diversity on landscapes and
seascapes.
• Biodiversity is important to the survival of humans and their economy,
and also to all other species.
• Biodiversity also has inherent value.
• Human activities have resulted in the extinction of many elements of
biodiversity, and the survival of many others is being placed at grave risk.
• Damage to biodiversity is a principal aspect of the environmental crisis.
5. Types of Biodiversity
• Biodiversity measured by number of different species, their relative
abundance and their spatial distribution
• Landscape biodiversity- variations over places; endemism
• Community biodiversity- species richness and evenness
• Population biodiversity- genetic variation- out breeding
6. Biodiversity Loss- Habitat destruction and Extinction
• Biodiversity is the variety of life in all its forms and combinations at all level of
ecological organisation but also essential for human beings
• Biodiversity is essential for survival and for our livelihood
• Supplier of essential ecosystem services- cannot be replaced by technological
intervention
• Ecosystem take millions of years to acquire stability- and may get disturbed in
few years especially in the age of Anthropocene
• Three dominant changes- a) shrinking of habitat b)Loss of biodiversity c)
Extinction of species
• Global terrestrial plant mass have reduced by 45 per cent in last 2000 years-
1/3rd of that in 20th century
• Habitat spaces are either highly degraded or modified
7. Extinctions in prehistoric and historic ages
• Many species are useful as “resources” that humans can harvest and use as a source of
food, medicine, timber, fuel, or some other purpose. In many cases, the exploitation of
these potentially renewable resources has been so insatiable that their “mining” has
culminated in extinction. These once-valuable species now occur nowhere on Earth
(Freedman, 1995).
• Extinctions were caused by prehistoric hunters as well as they over-hunted populations of
large animals
• The colonization of “new” land masses by humans also caused mass extinctions in other
places.
• Unsustainable harvesting during historic times has caused some of the most famous
cases of extinction and endangerment, in some instances involving species that were
initially extremely abundant.
• Examples of the devastating effects that insatiable killing can have on vulnerable
populations of wild creatures- Such as Dodo, Great Auk, Passenger Pigeon, and others
• Many species have been endangered or extinct because their natural habitats were
converted to agricultural or other land-uses or were damaged by invasive alien species.
8. Threats to Biodiversity
• Habitat loss- land use change and deforestation
• Habitat fragmentation
• Overharvesting
• Non native species
• Pollution
• Altered patterns of disturbance
• Trade in endangered species
9. LPR 2020
• The 2020 global Living Planet Index shows an average 68% fall in populations of
mammals, birds, amphibians, reptiles and fish between 1970 and 2016.
• From the biggest to the smallest living things on our planet, monitoring shows us
that nature is in serious decline.
• 1 million species (500,000 animals and plants and 500,000 insects) being
threatened with extinction over the coming decades to centuries, although many
of these extinctions are preventable if we conserve and restore nature
• The most important direct driver of biodiversity loss in terrestrial systems in the
last several decades has been land-use change, primarily the conversion of
pristine native habitats (forests, grasslands and mangroves) into agricultural
systems; while much of the oceans has been overfished.
• Since 1970, these trends have been driven in large part by a doubling of the
world’s human population, a fourfold increase in the global economy, and a
tenfold increase in trade.
10. • Climate change will adversely affect genetic variability, species richness and populations,
and ecosystems.
• In turn, loss of biodiversity can adversely affect climate –increases the atmospheric
abundance of carbon dioxide, a key greenhouse gas.
• The loss of biodiversity is not only an environmental issue but a development, economic,
global security, ethical and moral one.
• The continued loss of biodiversity will undermine the achievement of most of the UN
Sustainable Development Goals.
• In 2019, drawing on almost 15,000 references and the expertise of more than 150 natural
and social scientists from more than 50 countries, the Intergovernmental Science-Policy
Platform on Biodiversity and Ecosystem Services (IPBES) published its first global
assessment on the state of the Earth’s biodiversity, the Global Assessment Report on
Biodiversity and Ecosystem Services.
• About half of the species in the LPI show an average decline in population size.
• The number of documented terrestrial plant extinctions is twice as high as for mammals,
birds and amphibians combined.
• Widespread losses of terrestrial insects since 1925 with mean global loss of 8.8 per cent
per decade.
12. LAND DEGRADATION
• Decline in the productive capacity of land
• Land degradation—the deterioration or loss of the productive capacity of
the soils for present and future
• It is affecting different places globally and at an alarming pace that is
reducing the most important ecosystem service that all living beings need.
• It is caused by multiple factors such as extreme weather conditions,
diminishing soil quality and presence of toxic material.
• Removal of natural vegetation and rapid deforestation everywhere have
reduced the ability of the land to regenerate on its own.
• Land degradation began with widespread adoption of agriculture during
Neolithic time, some 10,000 years ago followed by urbanisation that has
significantly altered ecosystems.
13. • Land degradation as per IPCC is defined as a negative trend in land condition,
caused by direct or indirect human-induced processes including anthropogenic
climate change, expressed as long-term reduction or loss of at least one of the
following: biological productivity, ecological integrity or value to humans.
• This definition applies to forest and non-forest land: forest degradation is land
degradation that occurs in forest land.
• Soil degradation refers to a subset of land degradation processes that directly
affect soil.
• Each year, the earth is losing 12 million hectares of land and global forest cover is
shrinking by 13 million hectares.
• According to a UNCCD REPORT, land degradation due to drought and
desertification affects about 1.9 billion hectares of land and 1.5 billion people
globally [EXTREME].
• Globally, 3.2 billion people are affected by land degradation of some form,
especially rural communities, smallholder farmers, and the very poor.
14. • Globally, about 25 percent of the total land area has been degraded.
• Scientists recently warned that 24 billion tons of fertile soil was being lost
per year, largely due to unsustainable agriculture practices.
• If this trend continues, 95 percent of the Earth’s land areas could become
degraded by 2050.
• The problems are particularly severe in the driest parts the planet, covering
approximately 40 per cent of the world’s land area that supports two billion
people.
• As land is degraded--- deserts expand in some places, food production is
reduced and water sources dry up, livelihood of millions are at stake.
• In Africa, some 60 million people face displacement within five years as
their land turns into desert.
• In fact, two-thirds of Africa’s fertile land could be lost by 2025 due to
growing desertification.
16. Dimensions of Land Degradation
• It is difficult to distinguish between human caused deterioration and natural changes. But
general nature of degradation involves impoverished and eroded soil with sparse or no
vegetation.
• Both deliberate and incidental changes to soil have been destructive and have resulted in
large scale degradation as soil is highly vulnerable
• World over, the problem has become critical due to unsustainable cropping and livestock
rearing, urbanisation and climatic changes.
• Besides, this the soil has degraded also due to large amount of unregulated waste which is
piled everywhere.
• The degradation sets in with following conditions-
➢Soil Erosion- Soil erosion is a naturally occurring process that affects all landforms as it
refers to the wearing away of the topsoil by the natural physical forces of water and wind;
also due to anthropogenic factors.
➢Drought – It is a period of time when an area or region experiences below-normal
precipitation.
➢Desertification- a type of land degradation in drylands in which biological productivity is
lost due to natural processes or induced by human activities whereby adjoining areas also
become increasingly arid.
17. DECLINING SOIL QUALITY
• Soil is a loose and unconsolidated material derived through breakdown of rocks and
rock material.
• Soils are complex mixtures of minerals, water, air, organic matter, and decayed matter.
• Natural soil is a product of
s= f(cl, o, r, p, t)
• A healthy soil is determined by its micronutrients,
pH value, permeability and soil moisture balance
• Soil is differentiated with respect to its physical
and chemical makeup, biological content and horizons
• Changes in one or more factors can lead to drastic
changes in soil properties and its ability to
support a certain type of vegetation.
18. Major factors of Vulnerability
• Chemical changes- salinisation, laterization
• Structural changes- compaction
• Hydrological changes- artificial draining of soil or even expansion due to
high water content
• Soil erosion- water or wind related
• Rain splash
• Wash erosion
• Gullies
• Wind deposition
➢EROSIVITY- Rainfall factors- raindrop and run off
➢ERODIBILITY- soil property, vegetation, topography and land use
19. Other Factors of soil degradation
• Soil carbon- Loss of carbon due to prolonged cultivation and
other land use changes
• Soil fertilisation- change in chemical property/deficiencies/toxic
excesses
• Fire- burning rapidly releases some nutrients but detrimental to
soil fertility; pH changes
• Invasive species- soil-moisture balance disturbed/deficiencies
• Excessive mining- erosion, loss of biodiversity, contamination
of soil, groundwater, and surface water by the chemicals;
collapse and cavities.
20. DROUGHT, DESERTIFICATION AND LAND DEGRADATION
• Drought, a complex and slowly encroaching natural hazard with significant and pervasive
socio-economic and environmental impacts, is known to cause more deaths and displace
more people than any other natural disaster.
• By 2025, 1.8 billion people will experience absolute water scarcity, and 2/3 of the world
will be living under water-stressed conditions
• Drylands are areas which face great water scarcity- cover over 40% of the earth's land
surface, and more than two billion people.
• They are highly adapted to climatic variability and water stress, but also extremely
vulnerable to damaging human activities such as deforestation, overgrazing and
unsustainable agricultural practices, which cause land degradation.
• Desertification, is the process by which natural or human causes reduce the biological
productivity of drylands (arid and semi-arid lands).
• Decline in productivity may be the result of climate change, deforestation, overgrazing,
poverty, unsustainable irrigation practices, or combinations of these factors.
21. • The concept does not only refer to the physical expansion of existing deserts
but rather to the various processes that threaten all dryland ecosystem,
including deserts as well as grasslands and scrublands and all marginal lands
• Desertification reduces agricultural output, contributes to droughts and
increases human vulnerability to climate change.
• The loss of biodiversity in drylands, including bacteria, fungi and insects living
in the soil, is one of the major causes and outcomes of land degradation.
• Restoring rangelands and sustainable land management practices can
preserve drylands biodiversity, restore ecosystem functions, and halt land
degradation.
22. UNCCD REPORT - United Nations Convention to
Combat Desertification
• The UNCCD report primarily focuses on the impact of desertification on different
parameters of economic and environmental development. The report, Land
Degradation due to drought and desertification affects about-
• Over 715 million hectares of degraded lands in Africa
• Over 550 million hectares in Latin America
• About 400 million hectares in southern and eastern Asia
• Each year, the world is losing 12 million hectares of land, and thus the opportunity to
grow 20 million tonnes of grain. Moreover, 24 billion tonnes of fertile soil disappear
each year.
• The precariousness of the situation becomes more pronounced as 2.6 billion people
depend directly on agriculture and 52 per cent of the land used for agriculture is either
moderately or severely affected by soil degradation.
• Global forest cover is shrinking by 13 million hectares a year.
23. ➢Impact on food security
• In the next 25 years, land degradation may lead to a decline in global food production by up to 12
per cent, which might trigger a rise in food price by 30 per cent.
➢Water stress and loss of biodiversity
• Desertification and land degradation lead to the loss of biodiversity. According to the report,
27,000 species are lost each year due to this phenomenon.
• By 2030, water scarcity in arid and semi-arid places may lead to displacement of up to 700
million people.
➢Agricultural practices
• Finding flaws in current agricultural practices, the report stated that they contribute over 13 per
cent of total greenhouse gas emissions.
• Crop varieties and agricultural practices are not suitable to tackle impact of climate change,
which might further affect agricultural yields by up to 15‐50 per cent in most countries by 2050.
• It is important to note that the percentage of land area affected by serious drought has more
than doubled between 1970s and the early 2000s.
24. ➢Potential for restoration of degraded land
• While the threat of 50 million people being displaced within the next 10 years due
to desertification looms large, the report gives hope for reversing the trend.
• Over 2 billion hectares can be earmarked for forest and landscape restoration.
➢It also observed that desertification and land degradation has a disproportionate
impact on women and children. They are the worst affected since they are the
last to leave their land.
• Healthy land is a natural storage for fresh water. If it is degraded, it cannot perform that
function. Managing land better and massively scaling up land rehabilitation are essential
for building drought resilience and water security.
• Land restoration is the cheapest and most effective solution to improved water storage,
mitigating impacts of drought and addressing biodiversity loss.
• The UNCCD Science Policy Interface promotes a novel concept of Drought-smart land
management (D-SLM), based on scientific evidence on the linkages between land use and
drought, as well as their connection to water use.
25. What it means for future?
• These social and environmental processes are stressing the world's arable lands and
pastures essential for the provision of food and water and air quality.
• Land degradation and desertification can affect human health through complex
pathways.
• As land is degraded and deserts expand in some places, food production is reduced,
water sources dry up and populations are pressured to move and look for alternatives.
➢ Higher threats of malnutrition from reduced food and water supplies;
➢ More water- and food-borne diseases that result from poor hygiene and a lack of
clean water;
➢ Respiratory diseases caused by atmospheric dust from wind erosion and other air
pollutants;
➢ The spread of infectious diseases as populations migrate.
26. Land Degradation Neutrality (LDN)
• A state whereby the amount and quality of land resources, necessary to support
ecosystem functions and services and enhance food security, remains stable or
increases within specified temporal and spatial scales and ecosystems.
• About 122 countries have engaged with the LDN Target Setting Programme and
considerable progress has been made since the 2030 Agenda was adopted in
2015.
• LDN represents a paradigm shift in land management policies and practices.
• It is an unique approach that counterbalances the expected loss of productive
land with the recovery of degraded areas.
• It strategically places the measures to conserve, sustainably manage and restore
land in the context of land use planning.
• UNCCD- United Nations Convention to Combat Desertification, and the UNEP- UN
Environment Programme came together to mark the United Nations General
Assembly adoption of the "2030 Agenda for Sustainable Development" ---
highlights the importance of achieving LDN to make progress towards multiple
Sustainable Development Goals.
