Climate Change and Biodiversity

Climate change It refers to a change in the state of the climate that can be

identified (e.g. using statistical tests) by changes in the mean and/or

the variability of its properties, and that persists for an extended

period, typically decades or longer.

It refers to any change in climate over time, whether due to natural

variability or as a result of human activity.

Climate in a wider sense also includes not just the mean conditions,

but also the associated statistics (frequency, magnitude, persistence,

trends, etc.), often combining parameters to describe phenomena

such as droughts.

This usage differs from that in the United Nations Framework

Convention on Climate Change (UNFCCC), where climate change

refers to a change of climate that is attributed directly or indirectly

to human activity that alters the composition of the global

atmosphere and that is in addition to natural climate variability

observed over comparable time periods.

It is different from weather…

Weather describes the conditions of the atmosphere at a certainplace and time with reference to temperature, pressure,humidity, wind, and other key parameters (meteorologicalelements); the presence of clouds, precipitation; and theoccurrence of special phenomena, such as thunderstorms, duststorms, tornados and others.

Climate in a narrow sense is usually defined as the average weather, ormore rigorously, as the statistical description in terms of the meanand variability of relevant quantities over a period of time rangingfrom months to thousands or millions of years.

The relevant quantities are most often surface variables such astemperature, precipitation and wind.

Classically the period for averaging these variables is 30 years, asdefined by the World Meteorological Organization.

Causes of climate change

Natural Causes

Human Causes

Short lived and long lived climate forces

Natural causes

Climate is influenced by external natural factors such as changes in

volcanic activity, solar output, and the Earth's orbit around the Sun.

Of these, the two factors relevant on timescales of contemporary

climate change are changes in volcanic activity and changes in solar

radiation.

Volcanic eruptions are episodic and have relatively short-term

effects on climate.

Changes in solar irradiance have contributed to climate trends over

the past century but since the Industrial Revolution, the effect of

additions of greenhouse gases to the atmosphere has been about

ten times that of changes in the Sun’s output.

Anthropogenic causes Burning of fossil fuels

Conversion of land for forestry and agriculture.

Agriculture

Industrial Revolution (CFC…)

Greenhouse gases

Livestock: responsible for 18% of the world’s greenhouse gas

emissions as measured in CO2 equivalents and 65% of human-

induced nitrous oxide

GJJ99 3Hadley Centre for Climate Prediction and Research

The greenhouse effect

SUNSome solar radiation is

reflected by the earth’s

surface and the atmosphere

ATMOSPHERE

Solar radiation

passes through the

clear atmosphere

EARTHMost solar radiation is absorbed

by the surface, which warms

Some of the infrared

radiation is absorbed

and re-emitted by the

greenhouse gases.

The effect of this is to

warm the surface

and the lower

atmosphere

Infrared radiation

is emitted from the

Earth’s surface

Changes in the

atmosphere,

land, ocean,

biosphere and

cryosphere

(both natural

and

anthropogenic)

can perturb the

Earth’s

radiation

budget,

producing a

radiative forcing

that affects

climate.

Rising temperature

Global average temperatures have increased ~0.6°C (1°F) in last 100 years

Temperatures at poles have increased by up to 9°F

Over last 30 years, annual average Arctic sea ice has decreased 8% (1 million km2)

Global sea level has risen ~10-25cm due to melting glaciers and permafrost and due to thermal expansion of oceans

2006, 2005, 2004, 1998, 2002, 2003, 2001, 1997 are hottest years on record

Global-average surface temperature projected to increase by 1.4 ºC to 5.8 ºC by 2100

Increasing CO2 level

Effects of climate change

Increased sea level

Rapid sea ice loss

Increased temperature

Increased extreme events

Ocean Acidification (The average pH of ocean surfacewaters has fallen by about 0.1 units, from about 8.2 to 8.1(total scale) since 1765 )

Hurricane Intensity Increases

Reduced agricultural productivity

Increased threat to biodiversity

What’s about sea level rise?

Source: R. Nicholls, Middlesex University in the U.K. Meteorological

Office. 1997. Climate Change and Its Impacts: A Global Perspective.

So

urc

e: I

PC

C 2

001

TEN MILLIONS OF PEOPLE MUST MOVE AWAY WHEN Sea level rise IS

HIGH

Kilimanjaro 2000

Ice on Kilimanjaro

0

5

10

15

1900 1920 1940 1960 1980 2000 2020

Year

Are

a (

km

2)

Effect on ecosystem

Climate change is projected to occur at a rapid rate relativeto the speed at which forest species grow, reproduce and re-establish themselves (past tree species’ migration rates arebelieved to be on the order of 4–200 km per century). Formid-latitude regions, an average warming of 1–3.5°C over thenext 100 years would be equivalent to a pole-ward shift ofthe present geographic bands of similar temperatures (or“isotherms”) approximately 150–550 km, or an altitude shiftof about 150–550 m.

Therefore, the species composition of forests is likely tochange; in some regions, entire forest types may disappear,while new assemblages of species and hence new ecosystemsmay be established.

(AR5)”

Effect on water sources

Changes in climate could exacerbate periodic and chronic shortfallsof water, particularly in arid and semi-arid areas of the world.

Developing countries are highly vulnerable to climate changebecause many are located in arid and semi-arid regions, and mostderive their water resources from single-point systems such asbore holes or isolated reservoirs.

These systems, by their nature, are vulnerable because there is noredundancy in the system to provide resources, should the primarysupply fail. Also, given the limited technical, financial andmanagement resources possessed by developing countries,adjusting to shortages and/or implementing adaptation measureswill impose a heavy burden on their national economies.

There is evidence that flooding is likely to become a larger problemin many temperate and humid regions, requiring adaptations notonly to droughts and chronic water shortages but also to floodsand associated damages, raising concerns about dam and leveefailures.

• Ecosystem services: mountains influence rainfall patterns and

mountain forests prevent erosion & floods

• Mountain communities are marginalised, with little access to

urban resources and limited agricultural land

• Language diversity in mountains is high, and threatened

languages are common in mountain regions

The Importance of Mountain

Environments

Mountain Watch

The first global assessment of mountain ecosystems

Scale of Change

20% of the world’s

coral reefs were lost

and more than 20%

degraded

35% of mangrove

area has been lost in

the last several

decades

Wood fuel is the only source of fuel for one third of the world’s population

Wood demand will double in the next 50 years

Forest management will become more difficult due to an increase in pests and fires

One third of the world’s population is now subject to water scarcity

Population facing water scarcity will more than double over the next 30 years

Climate change is projected to decrease water availability in many arid- and semi-arid regions

Indian scenario wrt climate change

Effects on rainfall in India

Source from presentation of Dr. R. K. Bhatt, Principle Scientist CAZRI Jodhpur

Atmosphere

Rainfall

Rise in

Temperature

Change in

Rainfall

Living organisms

Changes in plankton

biomass

Wildlife Agriculture

Carbon,methane,nitr

ous oxide,

Cholorofluoro

carbons

Changes in behavior,

migration pattern,

Flowering time

Change in crop

biology

CLIMATE CHANGE AND BIODIVERSITY

How to protect biodiversity in changing climate In general, there are two different strategies when it comes

to dealing with climate change. We can try to stop futurewarming (mitigation of climate change) or we can findways to live in our warming world (adaptation to climatechange).

Adaptation involves developing ways to protect peopleand places by reducing their vulnerability to climate impacts.For example, to protect against sea level rise and increasedflooding, communities might build seawalls or relocatebuildings to higher ground.

Mitigation involves attempts to slow the process of globalclimate change, usually by lowering the level of greenhousegases in the atmosphere. Planting trees that absorb CO2from the air and store it is an example of one such strategy.

Mitigation to climate change

Organic farming

Use of chemical input will

reduce the biodiversity

Thank you