2. INTRODUCTION
Climate is the underlying force which stimulates life on the planet.
From microorganisms to the largest existing animal the blue whale;
climate is the force which triggers their functioning.
Climatic change drastically impacts life, us the homo-sapiens are also programmed
by nature to perform according to climate.
A change in the climatic conditions of a region can only be for the worst.
Being currently the dominant species on the planet and believing to command
everything on the planet and understand nature, it is ironic that a minute variation
in climate can threaten our dominion status.
Are we being ignorant of other species? Are we taking mother Earth for granted?
The inhuman human activities in the name of development and monetary benefits
are leaving only one choice for our fellow beings and that is to just disappear
forever.
The paper studies about the climate changes which has happened during the past
and relation with the present and the amount of effect it has brought about during
the passage of time in the form of species’ extinctions and whether we are moving
towards another possible 6th Extinction1 ?
Beginning from the meaning of climate which comes from the Greek word klima
meaning 'area', usually refers to a region's long-term weather patterns. This is
measured in terms of average precipitation (i.e. the amount of annual rainfall, snow
etc.), maximum and minimum temperatures throughout the seasons, sunshine
hours, humidity, the frequency of extreme weather, and so on.
Due to this prolonged nature it is important to study and understand exactly what
to expect in the long run.
This is where the subject of climate change comes relevant, climate change usually
refers to global climate change, or long-term variations in the planet's average
temperature. But it can also be used more generally to mean local and regional
1 With Reference to Elizabeth Kolbert’s Book ’ The Sixth Extinction’
3. changes in weather patterns. The global average temperature is influenced by many
interacting systems which, together, we call the climate system. But, of course,
global climate change also affects regional climates.
Analyzing the reasons for these climatic changes leads us to the conclusion the
changes are anthropogenic in origin. When global biodiversity is gradually being
altered by human activities, species respond differently to such alterations in
response to habitat destruction and habitation fragmentation either by adapting to
it or by becoming extinct.
WHY IS CLIMATE RELEVANT?
Simply stating climate is as important to us as much as natural resources like fresh
water, oxygen, trees etc. are. Climate acts as one of the stimulants for life. Climate
regulates the activities of all the living organisms. Our agriculture is dependent on
climate, our biological cycle is dependent on climate. We are wired to behave
accordingly to the climate, if the climate cycle gets unbalanced, then from microbes
to the humans, all will slowly die. In order to prevent such mass extinctions it is
necessary to understand and protect our climate.
”God always forgives, man occasionally forgives but nature never forgives” -as
quoted by Pope Francis.
THE HISTORY OF CLIMATE CHANGE:
Climate has been always subjected to changes, throughout the history of the planet
there is evidence that it has happened and affected the Earth throughout geologic
time. Evidence of past climate change comes from the geologic record of ancient
environments and glaciers, fossils of plant pollen, isotopes of elements such as
carbon and oxygen, tree rings, and fossil distributions. The age of these can be
determined by carbon dating. Then the question arises why we are alarmed about
it today? The answer is that we are accelerating the process of climate change to a
very unrecoverable position and the results are horrifying.
4. The following are the BIG FIVE extinctions, which are recorded proof of the harm
climate change can bring about in the ecosystem. By analyzing these past
occurrences we are able to understand what climate change is and how to tackle it.
1. The Ordovician Period
The Ordovician Period lasted almost 45 million years, during this period, the
area north of the tropics was almost entirely ocean, and most of the world's
land was collected into the southern supercontinent Gondwana. Throughout
the Ordovician, Gondwana shifted towards the South Pole and much of it was
submerged underwater.
The Ordovician is best known for its diverse marine invertebrates, plus red and
green algae, primitive fish, cephalopods, corals, crinoids, and gastropods.
From the Lower to Middle Ordovician, the Earth experienced a milder climate
— the weather was warm and the atmosphere contained a lot of moisture.
However, when Gondwana finally settled on the South Pole during the Upper
Ordovician, massive glaciers formed, causing shallow seas to drain and sea
levels to drop. This particularly affected the corals and bryozoans that were
living in shallow inland seas, which drained of water. Global cooling spelt
disaster for warm-adapted species that had nowhere to migrate This likely
caused the mass extinctions that characterize the end of the Ordovician in
which 60% of all marine invertebrate genera and 25% of all families went
extinct to.
A picture of the Ordovician sea.
5. 2. Devonian Period
When the Devonian period dawned about 416 million years ago the planet
was changing its appearance. The great supercontinent of Gondwana was
headed steadily northward, away from the South Pole, and a second
supercontinent began to form that straddled the Equator. Known as
Euramerica, or Laurussia, it was created by the coming together of parts of
North America, northern Europe, Russia, and Greenland.
Red-colored sediments, generated when North America collided with Europe,
give the Devonian its name, as these distinguishing rocks were first studied in
Devon, England. 2
Climate
The Devonian was a relatively warm period, and probably lacked any glaciers.
The temperature gradient from the equator to the poles was not as large as it
today. The weather was also very arid, mostly along the equator where it was
the driest. Reconstruction of tropical sea surface temperature from condont
apatite implies an average value of 30 °C (86 °F) in the Early Devonian. CO2
levels dropped steeply throughout the Devonian period as the burial of the
newly evolved forests drew carbon out of the atmosphere into sediments; this
may be reflected by a Mid-Devonian cooling of around 5 °C (9 °F). The Late
Devonian warmed to levels equivalent to the Early Devonian; while there is no
corresponding increase in CO2 concentrations, continental weathering
increases (as predicted by warmer temperatures); further, a range of
evidence, such as plant distribution, points to Late Devonian warming. The
climate would have affected the dominant organisms in reefs; microbes would
have been the main reef-forming organisms in warm periods, with corals and
stromatoporoid sponges taking the dominant role in cooler times. The
warming at the end of the Devonian may even have contributed to the
extinction of the stromatoporoids.
2 Reference from National Geographic website
6. 3. The Permian mass extinction
(Also nicknamed the great dying)
The Permian mass extinction (251.9 million years ago) has been nicknamed
The Great Dying, since a staggering 96% of species died out. All life on Earth
today is descended from the 4% of species that survived. The event turns out
to have been complex, as there were at least two separate phases of extinction
spread over millions of years. Marine creatures were particularly badly
affected and insects suffered the only mass extinction of their history.3
Relation of this great dying with climate change
Due to gigantic volcanic eruptions and release of huge amount of lava covering
100000sq.ft in fire from the Siberian traps, the global temperature rose by a
staggering 5 degree Celsius making the entire planet inhospitable for life. The
volcanic activity released high volumes of CO2 gas into the atmosphere leading
to global warming at an enormous scale. The mass extinctions occurred in
three phases killing off land and marine life.
The release of methane gas from the sea beds due to increase in temperature
in the water further accelerated the global warming by an alarming 10
degrees.
The climate change thus caused killed of 96% of all life on planet Earth. The
unfortunate period very much holds relation to today
where increase in greenhouse gas emission are gradually paving the way
forward for a mass extinction.
3 Reference from Scientific America article dated 24-10-07
7. 4. Triassic-Jurassic mass extinction
After the cataclysmic Late Permian mass extinction, it took 10-20 million years for
life to recover its previous diversity. But it did recover, and in significant new ways.
This was particularly true of vertebrates. Mammal-like reptiles flourished. Walrus-like
reptiles, placodonts, appeared in the shallow seas. Sharks and fish diversified.
And giant reptiles - the dolphin-like ichthyosaurs - became the top marine
predators. One of the main beneficiaries of the Late Permian mass extinction may
have been the dinosaurs. Their early ancestors emerged within about 5 million years
of the event.
While the first dinosaurs were only dog-size, by the end of the Triassic Period 6-
metre-long giants had evolved. Then the good times came to an abrupt end as Earth
was thrown into environmental chaos once again.
Causes for the chaos
This extinction is probably the least understood of the big five, because of the lack
of accessible sediments for scientists to study. Most of the evidence suggests falling
8. sea levels were probably responsible for the longer-term extinction patterns. As the
warm shallow seas decreased, reefs died and other marine organisms faced
increased competition in less space. On land the lack of water would have led to
more extreme temperatures and seasons. When deep water spread back over the
continents it was low in oxygen, resulting in further marine extinctions.
While the ultimate cause of this sea fall and rise isn’t certain, it appears to be
associated with the start of a volcanic rift forming between the Americas and Africa
and Europe. This would eventually produce the Atlantic Ocean. At the end of the
Triassic, very large eruptions occurred along the rift zone (known as the Central
Atlantic Magmatic Province) for about 500,000 years. The environmental changes
these caused put further stress on life on Earth.4 Large quantities of methane gas
created stress on the ecosystem adding to the global warming. Climatic changes
finally ends up the cause.
5
5. Cretaceous – Tertiary mass extinction
The Cretaceous-Tertiary mass extinction - also known as the K/T extinction - is
famed for the death of the dinosaurs. However, many other organisms perished at
the end of the Cretaceous including the ammonites, many flowering plants and the
last of the pterosaurs. Some groups had been in decline for several million years
before the final event that destroyed them all. It's suggested that the decline was
4 Reference from Discovery channel
5From BBC Nature
9. due to flood basalt eruptions affecting the world's climate, combined with drastic
falls in sea level. Then a huge asteroid or comet struck the seabed near the Yucatan
Peninsula in Mexico and was the straw that broke the camel's back.
Climate
Earth’s geography was transforming radically. As the land separated into some of
the continents we know today, ocean currents and climate were changing. Then,
sea levels dropped significantly and rapidly, falling as much as 150 meters in less
than 1 million years. But it reduced large inland seas such as the Western Interior
Seaway of North America, with a knock-on impact on terrestrial habitats, including
those important for dinosaurs. At the very end of the Cretaceous, intense volcanic
activity rocked the planet. Ash and toxic gases poured into the atmosphere, sending
temperatures plummeting and causing acid rain. As plants perished, herbivores and
their predators would have starved.
The intense volcanic eruptions would also have ejected vast amounts of carbon
dioxide. Scientists speculate that this caused ocean acidification, poisoning the
phytoplankton that larger marine animals relied on for food. Since these
phytoplankton would normally remove carbon dioxide from the atmosphere
(storing it as calcium carbonate in their skeletons), levels of this greenhouse gas
were able to rise unchecked. Scientists estimate that temperatures may have
increased by as much as 10°C, warming the oceans by up to 4°C and putting stress
on species, particularly those already living in tropical areas. It seems the volcanic
eruptions and meteor impact were probably the final straw for species already
suffering from the effects of sea-level changes.
10. Conclusions drawn based on the events above:
1. From the analysis of the above cases we can easily say that climate was the
underlying factor which determined the fate of the creatures (even the
dominant ones). In some cases external factors like meteoroids did a play a
part but it acted as a final nail on the coffin.
2. Temperature rise gave way for creation of inhospitable ecosystems.
3. Carbon and methane played a vital role in the mass extinction.
4. It can happen again.
11. 6
Are we heading for a 6th Extinction?
We just crossed CO2 levels of 400ppm which is the highest levels found on earth in
millions of years. As carbon dioxide is a greenhouse gas this means the temperatures
are only set to rise unless we take necessary steps. We have already lost a
considerable amount of flora and fauna. The concept of an ongoing sixth extinction
is beautifully portrayed in Elizabeth Kolbert’s book The Sixth Extinction.
Earth is losing its biodiversity fast due to human activities but the proof to whether
it will lead to another mass extinction can only be verified by analyzing some of the
cases.
1. The case of the declining amphibian population
6 2012 was marked as the hottest year in the 21st century, it resembles the geographical history.
12. Amphibians are particularly sensitive to changes in environment, amphibians have
been described as a marker species or the equivalent of “canaries of the coal mines”
meaning they provide an important signal to the health of biodiversity; when they
are stressed and struggling, biodiversity may be under pressure. When they are
doing well, biodiversity is probably healthy. Unfortunately, as has been feared for
many years now, amphibian species are declining at an alarming rate. If current
estimates of amphibian species in imminent danger of extinction are included in
these calculations, then the current amphibian extinction rate may range from
25,039–45,474 times the background extinction rate for amphibians. At an alarming
rate many of the varieties of amphibians like the panama golden frog have become
extinct from being endangered.
7
It has been observed that the species could not adapt to the new world we had
made, they lost their habitats and their resistance to fungal diseases dwindled and
many died off (as in the case of Panama frogs).
1. Dwindling fish stock
The UN’s 3rd Global Biodiversity Outlook report, mentioned earlier, notes that,
“About 80 percent of the world marine fish stocks for which assessment information
is available are fully exploited or overexploited. Fish stocks assessed since 1977 have
experienced an 11% decline in total biomass globally, with considerable regional
variation. The average maximum size of fish caught declined by 22% since 1959
7The Golden Toad of Monteverde, Costa Rica was among the first casualties of amphibian declines. Formerly abundant, it was last
seen in 1989. Source WIKIPEDIA
13. globally for all assessed communities. There is also an increasing trend of stock
collapses over time, with 14% of assessed stocks collapsed in 2007.8”
Increased fishing activities have led to the oceans being swiped clean of its stock of
fisheries. IPS reports that fish catches are expected to decline dramatically in the
world’s tropical regions because of climate change. Industrialized fishing methods
have depleted the fish and it is feared it is irrecoverable. We must understand that
each life form works together and only then can harmony be achieved, ocean
ecosystems help in reducing carbon by absorbing it, helps in recycling sewage and
helps in regulation of water cycle.
2. Declining ocean biodiversity due to acidification, oxygen loss and
temperature increase.
3. Rapid loss of forest cover.9
9*
These cases force us to believe that the ignorance with which we act could be
leading us to a greater danger than we thought.
8 — Secretariat of the Convention on Biological Diversity (2010), Global Biodiversity Outlook 3, May, 2010, p.48
9 Alarming increase in loss of greenery
14. If we continue in this pattern we will face another mass extinction. In
comparison to earlier mass extinctions which took place in millions of years
the scenario today is fast approaching.
The choices we have made as a species, educated or inadvertent, have created
the following ecological stressors:
Rapidly changing atmospheric conditions
Warming above typical interglacial temperatures as CO2 levels continue
to rise
Habitat fragmentation
Pollution
Overfishing and overhunting
Invasive species and pathogens (like chytrid fungus)
Expanding human biomass
We are being mute witnesses to many of the extinctions going around us in
our short life span which itself proves that it has become an accelerated
process.
15. Why we cannot afford extinction?
We have no right to decline the right to live that our fellow beings (plants
& animals) have; we are and never were dominant, we can only co-exist.
Due to mass extinction of our plant species we are fast losing forest
cover, important for both rain water cycle and
groundwater accumulation.
Disturbing Ecosystem Equilibria
Ultimately it will end in utter turmoil, destabilization of the ecosystem
can have devastating effects.
Measures Implemented and can be implemented:
So far we have discussed about all the negative aspects of climate change and
extinction. Now some of the measures implemented and can be implemented to
prevent it are:
1. In order to prevent further destruction it is important to spread awareness
among the general public.
A similar approach is being done in India by NDTV by launching a massive
awareness campaign to save the tigers. As a result of which they were able to
keep in check poaching and illegal sales.
2. By resorting to clean energy and ditching fossil fuels.
3. By protecting endangered species legally and structurally by creating
sanctuaries.
4. Controlling industrial fishing
16. 10
Conclusion
Nature was never ours and it will never be also, the other 5 extinctions are
examples to us, a nature’s way of warning us and we must heed to this warning or
otherwise we will perish just as the other dominant species did.
10 WORLD WILD FUND FOR NATURE AIMS AT PROTECTING ENDANGERED SPECIES.
