Lecture 2: State of Global Environment (Biodiversity)

welcome to the course environmental impact assessment continuing with our exploration to

review the status of the global environment today we will cover

biodiversity we will follow chapter 6 of global

environment outlook 6 which focuses on healthy planet and healthy people so

accordingly our coverage will include meaning of biodiversity we will look at

the problems associated with biodiversity like sixth mass extinction its significance

benefits and concept of one health we will review the interconnections

between people biodiversity and health and provisions of ecosystems

we will look at the key impactful pressures on biodiversity

thereafter we will review impacts on the world's biomes

so accordingly what you will be able to do is to explain

biodiversity explain and review problems associated with biodiversity like sixth mass

extinction its significance benefits and concept of one health

synthesize the interconnections between people biodiversity ecosystem health and

provisions of ecosystems and eventually connect these to understand

environmental impact assessment you should be able to identify the key pressures and bio diversity and review

various impact predictions identify the various worlds biomes and

discuss the impacts on them as well as review the nature and intensity of environmental impact

let us first understand what biodiversity means biodiversity is the richness and variety

of life we see on earth biodiversity relates to variability

variability the variety we see among living organisms from all sources the

diversity within species between species and of ecosystems we see

that biodiversity is said to be the health of ecosystem which allows for

stability and recovery it is said to be the most complex and important feature

of our planet without biodiversity life will not sustain when we consider

diversity we ask how many different species are present in a given area

we look at amount of inherited genetic variability contained within populations

of species survival of species is dependent on genes that provide

resistance to disease and environmental tolerance this can be significantly affected by

the destruction of habitats and other influences what we have been doing

we also look at ecosystem diversity like variety of communities or habitats that

exist now let's investigate the problems associated with biodiversity

an important concern for us is that biodiversity is in crisis there is well

established evidence that indicates an irrevocable

meaning permanent and continuing decline of genetic and species diversity and

this degradation of ecosystem is happening at local and global levels

scientists are increasingly concerned that if anthropogenic

the human activities pressures that are our activities exert in biodiversity

continue unrestricted without limits we risk

precipitating a sixth mass extinction event in the earth's history

and this will have tremendous impacts on our health and equity

here is a brief understanding of the sixth mass extinction

the national history museum says extension is a part of life and animals

and plants disappear all the time about 98 of all

organisms that have ever existed on our planet are now extinct

when a species goes extinct its role in ecosystem is usually filled by new

species or other existing ones earth's normal extinction rate is often

assumed to be between point one and one species per ten thousand species per

hundred years this is known as a background rate of extinction

a mass extension when we say mass extinction event is when species vanish much faster than

they are replaced this is usually defined as about 75 percent

of the world species being lost in a short amount of geological time less

than 2.8 million years it's difficult to identify when a mass

extinction may have started and ended however there are five big events that we know

of where extinction was much higher than the normal background rate which we talked about and these are often used to

decide whether we are going through a sixth one now

so now we understand what the sixth mass extinction means

subsequently our understanding of biodiversity is much better today we understand it much better in current

scenario here are some points that report indicates

rate of species loss is estimated to be a thousand fold greater than the

background rates that's what we see today this is rising concerns and debates among scientists

over whether we have already entered into a sixth mass extinction event for many species

populations are in decline globally and genetic diversity genetic diversity

which is vital for future adaptation to global change is deteriorating it is important for us

to understand that biodiversity loss and habitat decline continue to accelerate

so it's accelerating the decline is accelerating this decline is at a greater speed and

is believed to be beyond the planetary boundaries the loss of biodiversity reduces

ecosystem resilience the ability to get back to normal furthermore the loss

increases vulnerability to threats including negative impacts of climate

change the genetic diversity we see is vital

raw material which allows adaptation to these changes so if we lose that the adapt will also lose the ability to

adapt as per the report natural communities

of plants and animals are being reshaped because of climate change and our

activities which has caused movement of species we also see that some displaced species

are invasive aggressive and the pose risks

to not only to our health but also the genetic diversity

and food and water security so you see how significant they are in our life

such changes are said to reduce the efficiency of ecosystems ecosystem will not efficiently capture

essential resources it will not produce biomass will not decompose and recycle nutrients

and it will also decrease in resilience we see that there is increase in the

rate of species population decline globally across all earth's major biomes

and this is well established through various studies the report also highlights that at a

local level indigenous people and local communities play a key role in

protecting biodiversity and if we do not take action it will be

very expensive for us moving on let us look at the benefits of

biodiversity it is well established that biodiversity provides many valuable goods and

services to us this variability the variety we talked about helps to regulate climate through

carbon removal and control of local rainfall filters air and water

and mitigates the impact of natural disasters such as landslides and coastal

so it also even protects us direct benefits from biodiversity

include food and fibers from natural vegetations wood and non-wood products from forest

fish and oceans and fresh water systems pollination of crops medicines from

plants and even psychological health if we restore and maintain biodiversity will

be able to enhance adaptive potential of our earth and help

sustain nature's contribution for our livelihoods health and well-being

the report also suggests that loss of biodiversity is a significant equity issue

so as explained the livelihoods of 70 percent of people living in poverty rely

to some extent on natural resources if we damage these resources we put the

livelihoods of many at risk furthermore the report assesses

that 80 percent of global biodiversity is found in traditional territories of

indigenous people and stresses that the future generations of these

indigenous people will experience relatively impoverished poor life

if losses continue to happen so you see how how big the problem is

the report indicates that the pressure on biodiversity continues to increase there is loss of habitat degradation

because of agriculture and infrastructure development

then there are over exploitation and pollution we also see invasive alien

species and now we are experiencing climate disruption

furthermore these changes are interacting between themselves and causing further change so all the

changes which we're seeing they are also interacting between themselves we have noted and continued to

substantially ongoing losses of population species and habitats

let us try to understand the concept of one health the report states one health

is an approach that recognizes the opportunities and challenges

related to these interconnections at the human animal ecosystem interface

and aims for optimal health outcomes for all it is particularly relevant in the

prevention and control of zoonosis which account for more than 60 percent

of human infectious disease several aspects such as urbanization

agricultural practices land use and biodiversity are changing the ecological

dynamics and these changes are also in some cases facilitating human animal conflict and

these changes are also in some cases facilitating human animal contact that

worsens the risk of zoonotic disease emergence and spread for example corbin 19 which we are

experiencing now zoonotic diseases are transmissible from domestic or wild animals to humans

through direct contact or through water food and the environment

all these aspects of the study was published in 2019 which makes a very strong case for the reflection

what we are going through at this moment consider the drivers of environmental

change we have already seen that these drivers include

population demography urbanization economic development

technology and innovation and climate change these have caused several negative

impacts on biodiversity which in turn have led to loss of

genetic diversity which is important for the survival and arrest population

decline and because of these changes some of these species will disappear

furthermore such changes are also leading to reshaping of natural communities while creating concerns for

stability and functioning of ecosystems let us try to understand

interconnections between people biodiversity ecosystem health and provisions of ecosystem through this

image by worldwide fund for nature in the figure we see that our population

associated consumptions and resources use patent trigger the indirect drivers such as

agriculture and forestry fishing and hunting urbanization and industrial development

use of water energy and require transportation

which create direct pressure on biodiversity and ecosystem as seen in the third row in dark green color

the direct pressure indicated include habitat loss changes and fragmentation in the habitat

over exploitation of resources occurrence of invasive species pollution

and climate change from our activities these pressures change the state of

global biodiversity shown fourth row in pink color changes as indicated include terrestrial

change change in fresh water quality and quantity and marine biodiversity

in the bottom most row we see the services benefits we get from ecosystem

the service include provisioning service like food medicine timber fiber bio

energy regulating services like water filtration waste

decomposition climate regulation crop pollination regulation of some human diseases

and we also see supporting services like nutrient cycling photosynthesis and so

on then we also see cultural services like enriching recreational aesthetic

and even spiritual also reflect that as it is predicted

that the population will increase and urbanization will increase

most of the drivers will increase they are going to further

create more pressure and it is predicted that climate change will become the dominant driver of biodiversity change

in the next few decades ultimately reducing pressures and biodiversity will

require addressing these drivers of change now let us look at the pressures

the main direct pressure on global biodiversity are

habitat stress and land use change invasive species pollution unsustainable use over

exploitation and climate change mainly as a consequence of higher

temperatures change in precipitation pattern and increasing frequency and

severity of extreme weather event and wildfires the spatial distribution and combination

of these pressures varies across the globe as you may see in the figure

which shows the global distribution of the threat

in red zone showing very high threat intensity and orange showing high threat

intensity and so on you may look at our country to identify the threat level as

per the study given here in the following graph you may see the

proportion of critically endangered endangered and vulnerable under

mammals birds and amphibians due to land use change and habitat loss which

constitute the major portion shown in dark green color you may see invasive species and lighter

shade of green and further pollution you may further see that over exploitation

shown in black color is another major reason for threats followed by atmospheric warming and extreme events

shown in grey looking at the first point pressures

land use change in habitat loss land use change which means what changes we make

to the existing land cover to put into use to meet our growing requirements

such as for residential purpose in particular we are seeing

in the urbanization process industrial purposes infrastructure purposes mining for

agriculture purposes is increasing drastically therefore the associated

global human footprints like how much we are really consuming our footprints are

increasing assessing into the natural areas

leading to because of this we are causing desertification deforestation and also causing loss of

habitat so continue to think about the environmental impact our activities have

we see that land use changes impact both aquatic and terrestrial environments

with exposure to pollution exhausting pathogens and emerging infectious diseases harmful to humans livestock and

wildlife and we also see increased human conflict

as you can see in the figure which shows the global human footprint for 2009 based on the combined pressure of

infrastructure land cover and human access into natural areas in the scale

from 0 to 50 50 you may see indicated in red colors

you may look at india and reflect on color likewise pay attention to the

other warm color zones in the map in the following map you can see

the absolute change in average human footprint from 1993 to 2009 at the

echo region scale the zones indicated in red color show

the change in the negative directions and these areas the human footprint

change is highly degraded in orange color you may see the changes

again in the negative side and shows that it is degraded

the zone colored in green show improvement areas you may pay attention to footprint change in india as per the

study given here so through these figures you may reflect upon how much we are changing

and accessing into the natural areas

let us look at the second number of pressure identified invasive species

the report suggests that in developing countries due to inadequate planning

often the development coincides with biodiversity hot spots so we end up

interfering with that also it is suggested that the road construction assessed the spread of

invasive species and allow for easier access into previously intact habitat

exposing the species to threats from hunting and resource exploitation

invasive species threaten ecosystems habitats and other species they are usually non-native

um like invasives alien species but can also include expanding native species

that when they go beyond their proportion looking at the ecological impact of

invasive species it is said that they have direct and indirect competition

suggest predation that is praying of one animal on others

the action of attacking or plundering studies suggest habitat degradation

indicate hybridization which is the process of an animal or

plant breeding with another individual another species or variety

further importantly what we see now which is the which is threat on human

health and food security their role as disease agents and vectors

it is also indicated that the invasive plants can impact the provisioning of key ecosystem services which we have

already seen you can see reflect the diagram here and

look at all the ecosystem services we had discussed about so that's all been impacted we also see that invertebrate

species which are animal without backbone that have become invasive may pose an even greater risk

the population expansion example which we are seeing here of invasive zebra mussel in

the north american great lakes was so great that it impeded water flow of

municipal water supplies and hydroelectric companies

the danger is particularly high on islands because of invertebrate species

they can cause biodiversity loss to great extent

i have also linked the youtube video here for your further detailed understanding if you

wish to see invasive pests such as gypsy moth in north america as we can

see here in the picture has impact on biodiversity and economy

likewise we see another invasive species emerald ash borer in north america

impacting biodiversity and economy it was introduced in u.s you see how things

happen it was introduced in u.s in 2002 it arrived accidentally in cargo imported

from asia impact of this as recorded by national invasive species information center us

department of agriculture show that ash trees lose

most of their canopy within two years of infection so it just take two years and

die within three to four years so that that range of

damage can happen yet another recorded by national invasive species information center

again the u.s department of agriculture show hemlock woody adelgid in north america impacting the

biodiversity and economy it is native to japan this was also introduced by

accident destroys eastern hemlock trees you may also see

the youtube video to learn more link provided in the suggested read and watch it is also suggested that the invasive

insect vectors can also facilitate the spread of parasites and lead to

infectious diseases you are very much familiar with chikungunya dengue and zika which are

vectored by mosquitos we also see unsustainable uses and over

exploitation because of construction of dams mines and other hard as well as energy

infrastructure development so which we are going to constantly review in our environmental impact assessment

furthermore the climate warming and the increasing frequency of extreme weather

events we see these days like very hot summer

heavy rain causing flood season of scares rainfall causing drought and we

also see forest fires all of these contribute to habitat loss and

degradation of already stressed habitats because of the increased temperature the

seeds are getting warmer which we have already seen and that's reducing the sea ice extent

the reduction is affecting the critical hunting habitat for polar bears

seals and fishing birds as per the intergovernmental

panel on climate change ipcc reports we see also we see increase atmospheric carbon

dioxide and acidification of ocean habitats

we further see that the loss of habitat of wild species affect the ecosystem services mostly they provide as we have

seen pollinators and predators of agriculture pests report also notes the loss of human

access to late nature in particular it largely impacts the indigenous

communities so no more they are able to access nature that's that's been

obstructed the economic costs both direct and indirect such as cost of

efforts to control them can be of the range of many billions of dollars annually

and major routes for species invasive include deliberate relays escape accidental

introduction as you have already seen it could be tourism and

ship blast water as we had seen

wherever loss of native bias diversity happens it is likely to make it vulnerable to the invas invasion risk

so you reflect upon the nature of changes we make around and how it

eventually impacts us moving forward

we will look at another element which causes pressure that is pollution

pollution happens in many forms such as waste and chemical products deliberately

or accidentally released into the environment pollution in form of light noise heat

microbes major emitter of pollution includes transport industry agriculture

aquaculture so we see all these there are wide range of pollutants the increasing pollutants includes

synthetic chemicals pesticides cosmetics and so on you may think of the stuff you used

regularly pollution also happens through open waste dump on land which has local

impacts on plants and animals land soil pollution also leads to

impacting the microbial that is bacteria population and hampers

the important ecosystem functioning there are increasing problem of bio

accumulation of toxins including heavy metals which may have multiplying impacts across the entire

food chain including impact on us

probably problem of water pollution including marine and freshwater environment we see

increasing problem of plastics chemicals which threatens the wildlife

we are also witnessing air pollution that contributes to the acidification also eutrophication of terrestrial

ecosystems lakes estuaries and coastal waters and to mercury bioaccumulation in

aquatic food webs aquatic food webs

we also witness another pressure from over exploitation which includes illegal

unreported and unregulated activities such as phishing logging and so on

we see that the direct exploitation has resulted in threats to both

land and marine species the over exploitation of wildlife has

implications for equity as suggested it deprives poor and

vulnerable local communities and indigenous people who are dependent on

them for sustenance traditional medicines tourist income and other ecosystem

benefits so we see how our activities over

exploitation of the resources and impact of biodiversity and diverse and vulnerable communities

so we see how our activities over exploitation of the resources

impact biodiversity and how impact biodiversity

and also the vulnerable communities now we'll look at another driver climate

warming and extreme events creating pressure on biodiversity

the impacts of anthropogenic climate change on biodiversity are most evident

in natural systems the report suggests that up to one in

six species could be threatened with extinction by 2050 if current warming

trend continues in the figure you may see number of species vulnerable to climate change the darker shades

indicate high number of vulnerable species both in land and marine

the darker shade indicate high value as hundred species we may reflect on the

danger we see however known impacts are not distributed evenly

and our knowledge of impacts remain incomplete at this moment it is suggested that in response to rising

temperatures species may move to cooler locations or alter their phenology to flower

breathe or migrate sooner evidence suggests that they are doing both they are moving

up changing places as well as there's changes in the phenology to flower

now let us look at another extreme events the natural disaster such as earthquake and tsunami or flood land

slides wildflowers wild fires and droughts

following extreme weather even kill and injure hundreds of thousands of people a

year cause widespread destruction to ecological habitat and threatens

wildlife pollution with local extinction so they are also creating laws we further see marine

environments because of the warming and acidification there is

loss happening which we will see further in detail so we have seen the different drivers

which create pressures and biodiversity and range of impacts direct and indirect

we have seen them here briefly touched upon now we look at the global state and

trend of biodiversity global change what we are witnessing is

having negative impact across all dimensions of biodiversity which we discussed the changes are

happening from genes to ecosystems however we are yet not able to measure

the genetic diversity we are not aware ah further population baseline data is

also limited moreover the status of ecosystem is under evaluated so we should see this

keeping all this in perspective so when we review this you should be conscious

about this looking at the state and trends in genetic diversity genetic diversity is

important it is raw material for continuing adaptation of wild species by natural

selection it also helps in maintaining and enhancing the diversity of cultivated

plants and breeds of life stock this eventually helps in resilience of agriculture system and food security

we are witnessing long-term decline in the number of varieties of crops and breeds of livestock

there is decline of biodiversity at the global level so we have been repeating that

according to the international union for conservation and nature iucn latest

estimates in the figure you can see the red list of threatened species

the green color bar zone you can see critically endangered species you may note highest being cycad second from the

bottom you may see vulnerable in black color bar you may see sixth from the bottom the reef

forming coral are identified as vulnerable in

the figure showing the living planet index you can see the decline from 1970 to 2014 because of the anthropogenic

land use chains so you can see the decline here in the figure showing the biodiversity

intactness index you can see the spread of the decline and vulnerability of the species due to anthropogenic land use

change in the last 44 years look at the overall color distribution across the globe and also look at the colors in our

country study also indicates decrease in vegetation productivity between 2000 and

2013 because of anthropogenic factors a study also indicate that 24

of terrestrial echo regions are under danger in the figure you can see that the land

cover change in broad habitat such as mangrove tropicals subtropical

coniferous forest and also change in their productivity note the percentage

change and change in productivity study also indicate an average decline in natural wetland area about 30 percent

between 1970 and 2008 there has been increasing impact on marine ecosystems

due to anthropogenic activities many of these ecosystem processes are

thought to be under threat as a consequence of observed wildlife decline and ongoing threats to biodiversity

mammals bird amphibians species that are used for food or medicines are at

greater risk of extinction so we saw the state of biodiversity and

how it is declining rapidly at different scale and many of the processes

we are unaware of we will now look at the impacts on the world's biomes

let us first see what biomes are biomes are defined as a major ecological community of organism adapted to a

particular climatic or environmental condition across a large geographical area within biomes several ecosystems

may coexist you may see a lot of things here we see eight broadly defined biomes that

encompass most of the earth's biodiversity so that we are aware of different range variety we have

first we see ocean and coast as for the report the primary pressure on open ocean biodiversity are over exploitation

pollution from land-based activities and climate change

report suggests that coastal ecosystems have additional pressure associated with

habitat destruction aqua culture and invasive species coastal systems are

said to be particularly vulnerable for example between 20 and 35 percent of

mangrove areas have been lost since 1980 that is a big loss

and the current annual rate of seagrass habitat destruction is about eight percent coral reefs are among the most

biodiverse marine ecosystems they are most vulnerable and

under increasing decline all these decline is eventually affecting us second we see fresh water systems fresh

water system are exposed to multiple pressures because of land use change habitat loss invasive species use of

water courses for development and hydroelectric power and pollution we are creating widespread

and significant impact fresh water vertebrate species decline at a massive

scale report record averaged 81 percent over the past 42 years

that's huge six groups of global fresh water fauna assessed are in extinction risk as seen

in the figure amphibians mammals reptiles and so on about third of the

more than seven thousand fresh water in vertebrate species on the iucn red list

are considered threatened that's that's big number we are looking at these species combine to provide a wide range

of critical services for humans such as flood protection food water filtration

and carbon sequestration so they are important for us

now let us see the grassland as per iucn report grasslands cover

about eight percent of the total land area and were once home to some of the

largest wildlife collections on earth they have now drastically changed and

are now endangered ecosystem they are facing multiple pressure including land

use change over grazing fragmentation meaning that there's been disrupted invasive species suppression

of natural fire climate change and frustration

currently 4.5 percent of global grasslands have protected status so

there's lot of dependency of small and small scale economic activities on

grassland and degradation to such areas impact livelihoods of many

now let us look at the agricultural landscape agriculture expansion since thousands of years had led to

biodiversity loss in many biomes however we also see that

there are landscape transformation and fragmentation of natural habitat it is also non

cropped areas watercourses and air quality there has been drastic decline

in the animal population negatively impacting agricultural livelihoods

however some of the agricultural practices such as crop combinations and applications of

fertilizers and pesticides also impact on below ground biodiversity

the report also emphasizes that it is important to maintain the agricultural landscape as agriculture can sometimes

maintain rare species in semi-natural habitat so even that's important

now let us look at the dry land dry lands are said to be less diverse

than other ecosystems however they contain thousands of species that are

highly adapted to the dry land environment dryland species are highly

resilient and recover quickly from doubt from drought fire and

herbivore pressure we are witnessing worldwide desertification which is also known as land degradation

in dry lands dryland degradation has many causes including human conflicts

we see that large amount of waste garbage and toxic material were dumped

and burned in the desert ecosystem due to war drought over grazing overuse of

groundwater and unsustainable agriculture practices also impose extra pressure on the dry

land there are numerous impact of degradation of semi-arid and arid landscapes such as

availability of fresh water food production also affects the species and genetic

resources because of desertification we witness impact on soil health and vegetation

which eventually affects us salinization also happens which is a

major problem in this biomes let us now see forest we all know that forests

provide habitat for large numbers of animals and plant species

contribute range of ecosystem services provide essential regulation services

and we have seen all this deforestation and forest degradation is happening at a large scale and it is increasing

call increasingly causing threats to species diversity

and this is all happening due to demands of biomass urban expansion agriculture

energy mining and transportation development so when we do eia you look at all these

aspects if deforestation and degradation continue the forest can convert to

source of carbon itself there will be loss of livelihood there are direct health consequences of

deforestation ranging from physical and mental well-being forest laws increases exposure to

infectious disease including malaria and other vector-borne parasites let us now

look at mountains the report indicate that the mountain range covers around 22 percent of the terrestrial space of

planet and provide multiple ecosystem services mountain habitats at

lower elevation are more biodiverse we observe habitat degradation and

fragmentation and enha it has impacted many mountain ecosystems

we may note that the mountain ecosystems are especially vulnerable to climate

change the recorded impacts include shift in species ranges and composition climate

induced warming can change ecosystem functioning in the figure given you may see ecosystem function that mountain

provide with warm color showing high value of the services in the following

image you can see the pollution density indicating the demand on the ecosystem service

in the following image you can see the contrast of the supply and demand of ecosystem placed side by side look at

india as per the analysis the supply is low and the demand is high

as for the report most mountain areas today are under human pressure including the tropical ants

and central asian mountain biodiversity hot spots the himalayas

with approximately 19 000 species have been documented as highly vulnerable to climate change

looking at the impact of the laws of biodiversity and degradation of mountains it will lead to reduced

natural contribution to people in both mountains and low lands will result in changes in air quality

and climate regulation for example less green house gas will be controlled it

will cause loss of food security medicinal plants and water quality and provision and increased exposure to risk

associated with landslide sedimentation of rivers and flooding modifying their

livelihoods and land cover to the local communities glacier loss also impacts water security

many of our population particularly in south asian countries depend upon the flow of river from the himalayas

let us now look at the polar region polar region act as a sink for many anthropogenic pollutants

report shows that the biodiversity net arctic and antarctic region is under

particular stress there is decline in many native species there is increase in temperature

invasive species especially in the sub entatic and antarctic peninsula are

major pressures industrial development pollution local disturbances present

extra pressure many studies indicate that arctic will

be ice free in summer by 2050

the loss of sea ice will create major ecological shifts

and its impact can be several and we also see there is decline in penguin population in antarctica so

we see how diverse our bios diversity is and how it is under threat and what changes activities are causing to

summarize today's session so today we looked at the meaning of biodiversity we

reviewed the problems associated with the biodiversity like the sixth mass extinction its significance benefit

and concept of one health we looked at the interconnections between people biodiversity ecosystem health and

provisions of ecosystems and eventually

you are required to connect these while assessing environmental impact we identified the key pressures on

biodiversity and through this understanding you should be able to predict various impacts in today's

session we identified various worlds biomes and discussed impact on them and

you should alongside we may review the nature and intensity of environmental

impact what we choose to assess and what we do not choose to assess these were the references used for this

particular session our coverage has been limited as per the scope of the subject additional resources to read and watch

are provided to you please feel free to ask questions let us know about your any

concerns you have do share your opinions experiences and suggestions looking forward to

interacting and co-learning with you in our discourse of eia thank you