GLOBAL CLIMATE CHANGE.Basics,

Impacts & Challenges,

DR.THRIVIKRAMJI. K.P.PROFESSOR EMERITUS

thrivikramji@gmail.comCED, TRIVANDRUM

Global Climate Change

• Identifiable change in the climate of Earth as a whole that lasts for an extended period of time (decades or longer) – When due to natural processes, it is usually

referred to as global climate variability

– Usually refers to changes forced by human activities that change the atmosphere

Drivers of Earth’s climate change?

• Changes in the atmosphere• Natural processes

– Volcanoes – Tectonic plate movement– Changes in the sun

• Human activities – any activity that releases “greenhouse gases” into the atmosphere

What are greenhouse gases?

Any gases that cause the “greenhouse effect!”

Imagine… a car on a cool but sunny day…

Greenhouse gas (a.k.a. GHG) in an atmosphere absorbs & emits radiation

within thermal infrared range. H2O vapour, CO2, CH4, NOx, & O3.

Sans GHG Earth's surface would be ~33 °C (59 °F) or “unlivable”

Industrial revolution used energy (fossils fuels), & emitted CO2 ;

Rose from 280 ppm to 397 ppm.

May 13, 13 CO2 reached 400 ppm.

Arrhenius estimated that halving of CO2 would decrease temperatures by 4–5 °C (Celsius) & a

doubling of CO2 would cause a temperature rise of 5–6 °C. explain the ice ages. In 1896 he

calculated how changes in atmspheric CO2 levels could alter the surface temperature

through the green house effect.

Gas specific ContributionWater vapor, H2O, 36-72 %

Carbon dioxide, CO2, 9 –26 % Methane, CH44 – 9 %

Ozone, O33 – 7 %

Research

• Almost 1000 studies dealing with different aspects of climate change have been conducted and published

• So… how do we make sense of all this?

Intergovernmental Panel on Climate Change (IPCC)

• Why was it created?

– Created in 1988 by the United Nations Environmental Program

– Established to provide policy-makers with an objective source of information about climate change

Net sea level rise along the Arabian Sea coast has been 1-2 mm/y over

the past several decades, with Mumbai indicating a rise of roughly one-tenth of a metre over the last

100 years.

Al Gore, Hansen, J, & Pachuri, RPioneers - Trinity of GCC

Intergovernmental Panel on Climate Change (IPCC)

• Who is it?

– Governments

• Members of the UN

• Participate by naming experts and reviewing the reports before they’re published

– Scientists

• Close to 1000 scientists

• Climatologists, ecologists, atmospheric physicists, and others

Dr. Susan Solomon, a NOAA atmospheric chemist, an IPCC member and one author of IPCC summary

USA , (1132.7) ton/capitaChina, (85.4)

Russian Fed., (677.2) Germany, (998.9)

UK, (1127.8)Japan, (367)France, (514.9)

India, (26.7) Canada, (789.2)Ukraine, 556.4)

(per capita CO2 emission)

Prof. V.Ramanathan: On Soot

leading cause of respiratory diseases, responsible for some 1.9 million deaths a

year. melts ice and snow packs. Thus, sooty emissions from Asia, Europe and North America are helping to thin the

Arctic ice. Soot from India, China & a few other countries threatens water supplies fed by the Himalayan-Tibetan glaciers.

Prof. V.Ramanathan: On Soot

In China and India, a program to improve power generation, filter soot from diesel

engines, reduce emissions from brick-making kilns & provide more efficient

cookstoves could cut the levels of soot in those regions by about two-thirds — and

benefit countries downwind as

well. Stays in atmosphere for several days to about a decade.

Prof. V.Ramanathan: On Soot

Reducing soot & other short-lived pollutants would not stop global warming, but it would buy time,

perhaps a few decades, for the world to put in place more costly efforts to

regulate carbon dioxide.

% contribution of CO2 (Fossil fuels)

Liquid fuels (gasoline, fuel oil), 36 %Solid fuels (Coal)35 %

Gaseous fuels ( NG)20 %Cement production 3 %

Flaring gas (industrial & wells) < 1 %Non-fuel hydrocarbons< 1 %

"International bunker fuels" of transportnot included in national inventories 4 %

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CO2,CH4 and estimated global temperature (Antarctic ΔT/2 in ice core era)0 = 1880-1899 mean.

Source: Hansen, Clim. Change, 68, 269, 2005.

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If nothing is done to slow

greenhouse gas emissions.

. .

• CO2 concentrations will

likely be more than 700 ppm

by 2100

• Global average

temperatures projected to

increase between 2.5 -

10.4°F

2100

Source: OSTP

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Melt descending into a moulin, a vertical shaftcarrying water to ice sheet base.

Source: Roger Braithwaite, University of Manchester (UK)

Surface Melt on Greenland

Contribution to green house gases

HISTORY1896: Svante Arrhenius, Swedish chemist, gives CO2

warming theory due to coal burning 1924: Alfred Lotka, US physicist, speculates industrial activity will

double CO2 in 500 years1949: Guy Callendar, British scientist, links 10% CO2

increase from 1850 to 1940 with warming beginning in 1880’s

1958: Keeling, Scripps scientist, begins CO2 measurements at Mauna Loa, 315 ppm and rising

1976: Scientists identify CFCs, methane, and nitrous oxide as greenhouse gases

1985: UNEP, WMO, ISCU form consensus of international community about global warming

Challenges of dealing with Climate ChangeUnderstand the science – involves entire

interconnected “earth system” .Need to relate issues to non-scientists --

including policy makers .International in scope – a global issue

Involves forecasting .Wide range of impacts – ecological and human

conditions .Diagnosing changes and impacts with short

data records .

Challenges of dealing with Climate ChangeAttribution for observed changes; large

natural variability at all scales Conflicting literature – both scientific and public

Motivated disbelievers Political, economic, and social factors

Finding ways to mitigate effects Finding ways to adapt to changes

Finding ways to contribute as a scientist (hard to escape “big science”)

Challenges of dealing with Climate ChangeAttribution for observed changes; large

natural variability at all scales Conflicting literature – both scientific and public

Motivated disbelievers Political, economic, and social factors

Finding ways to mitigate effects Finding ways to adapt to changes

Finding ways to contribute as a scientist (hard to escape “big science”)

HISTORY

1988: Intergovernmental Panel on Climate Change (IPCC) established to prepare reports for 1992 Rio

Earth Summit 1995: IPCC 2nd Assessment “there is a discernable human influence on global climate” 1997: Kyoto Protocol adopted by 160 nations to give binding

obligations to limit emissions2001: IPCC 3rd Assessment “there is new and stronger evidence most of warming observed in last 50 years is

attributable to human activity”2002: Kyoto Protocol ratified by more than 100

nations – but not by U.S. or Australia; Bush calls for 10 more years of research

2005: Kyoto Protocol meeting in Montreal, Canada

2007: IPCC 4th Assessment “Very likely that greenhouse gas forcing has been the dominant

cause of the observed globally averaged temperature increases in the last 50 years”

Uncertainties…

1. Human induced forcing changes to present

2. Future emissions-- many scenarios A1FI: fossil fuel intensive energy system

A1T: non-fossil fuel intensive energy system

A1B: no one energy source relied on A2: self-reliant economy, preservation of

local identities

UNCERTAINTIES (CONT’D). B1: service & information economy, clean

technology, global solutions B2: B1 with local solutions, increasing

population, less technology 9. Model predictions - global mean

10. Model predictions - local conditions 11. Regime/abrupt changes

12. Impacts

Regime changes/ abrupt changes • Strong positive feedback cycles

• Disruption of ocean currents (e.g.Gulf Stream)

• Melting of glaciers and ice sheets Sea level rise if all melted (not counting

thermal expansion) Glaciers/ice fields --- 1.5 feet

Greenland ----------- 24 feetAntarctic ------------ 200 feet

Human Influences 1. Increase in greenhouse gases

3. Increase in aerosols 5. Change in surface conditions

(e.g. albedo, wind, evaporation) 7. Change in clouds

(e.g. contrails, pollutants, etc.)

Driving Forces for Future Human Impacts

1. Population 3. Economy (income per capita and regional differences) 5. Technology a. Energy production - fossil fuels and non-fossil fuels b. Energy use efficiency c. Land use 10. Energy structure: Coal - Oil/Gas - Renewables / Nuclear 12. Land use: Forests - Croplands & Energy Biomass –Other (grasslands, etc.) 6. Agriculture

Impacts on Humans & the Environment A. Terrestrial ecosystems

• Agriculture• Forests

• Desert and desertification• Hydrology and water resources

A. Ocean systems 1. Sea level

2. Coastal zones and marine ecosystems (including

biochemical factors, e.g. acidification)

Human “systems” 1. Settlements, energy and industry

2. Economic, insurance, and other financial services

3. Human healtha. Vector borne diseases

b. Water-borne and food-borne diseases c. Food supply d. Air pollution

e. Ozone and ultraviolet radiation

Atmospheric systems 1. Weather 2. Storms

3. Floods & droughts 4. Extremes

Perspectives WHY NUCLEAR POWER CANNOT BE

A MAJOR ENERGY SOURCE - David Flemming, April 2006

It takes a lot of fossil energy to mine uranium, and then to extract, and prepare the right

isotope for use in a nuclear reactor. It takes even more fossil energy to build the reactor, and, when its life is over, to decommission it

and look after its radioactive waste.

As a result, with current technology, there is only a limited amount of uranium

ore in the world that is rich enough to allow more energy to be produced by the

whole nuclear process than the process itself consumes. This amount of ore might

be enough to supply the world’s total current electricity demand for about six

years.

Moreover, because of the amount of fossil fuel and fluorine used in the

enrichment process, significant quantities of greenhouse gases are

released. As a result, nuclear energy is by no means a ‘climate-friendly’

technology

Kyoto Achievements at Montreal-2005 1. Launch negotiations for industrial-

country emission targets starting in 2013

2. Meet November 2006: review protocol effectiveness

3. Adopt 30 decisions made in past 5 years including

mechanisms to deal with countries falling short of targets

. Improve Clean Development Mechanism i.e., allow countries meet

obligations by helping developing countries in clean energy projects

. Agreement to help developing countries adapt to already evident impacts of CC .

. Numerous U.S. state officials & city mayors shared their serious willingness &

efforts to reduce emissions

Stern Report - UK Government - Oct. 30, 2006 – 576p

The Economics of Climate change Part 1: Climate change: our approach Part 2: Impacts of climate change on

growth & development Part 3: Economics of stabilization

Part 4: Policy responses for mitigation

Policy responses for adaptation : International collective actions,

Understanding international collective action for climate change, Creating a

global price for carbon .Supporting transition to low carbon global

economy, Promoting effective international

technology co-operation, Reversing emissions from land use change ,

International support for adaptation.

Why Should We Care?We don’t know exactly what will happen with global warming or what, where, and

when the impacts will be. Impacts could be far-reaching and cause serious problems.

Sea level will continue to rise, eroding beaches and increasing the damage from

storms and leading to loss of wetland habitats. Some island nations will

disappear.

Increasing temperatures are likely to affect human health:

• Warmer temperatures mean mosquitoes will spread. Diseases like malaria &

encephalitis.• Ground-level ozone pollution will likely worsen. Increasing respiratory diseases

like asthma.• Deaths from heat waves will rise.

• Some plants and animals may face extinction if habitat changes.

Changing weather patterns could affect agriculture. Northern states could actually experience longer growing seasons. The

U.S. Great Plains could have frequent droughts.

Some forests may disappear, leading to extinction of wildlife species, oceans will

become more acidic—changes in biodiversity. Economic effects: Billions of dollars in property damage from sea level

rise and worsening storms.

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How can we stop the earth’s “blanket” from getting us to warm?

• We must start putting less carbon dioxide into the air.

• Most the CO2 in the air will be around for 100 years.

• We need to burn less gasoline in our cars.

• Burn less coal (or burn it cleaner) for our electricity.

• Use less gas to heat our homes.

• Use less gas and electricity in our factories and on our farms.

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ALTERNATE SOURCES OF ENERGY VIS-À-VIS CARBON BASED FUELS ?

• Solar

• Biofuels

• Wind

• Nuclear Power (may be necessary whether we like it or not!)

• Geothermal

Carbon Cycle – Climate Change

• Carbon cycle – how carbon moves in earth, water atmosphere

• Carbon cycle impacts climate change, and climate change impacts carbon cycle

• Example: 16 gigatons carbon are locked up in arctic permafrost worldwide – HUGE amount.

• This carbon is on verge of melting due to global warming. If these melt, much will go into the atmosphere and increase greenhouse gases…leading to increase in temperature.

SUMMARYClimate change is a complex issue.

• Humans are changing earth & atmospheric conditions

• Anthropogenic climate change has scientific basis.

• Scientists agree that we are already seeing human impacts on our climate • Many uncertainties for global & local

outcomes of climate change • What we are doing now will affect

climate for our grandchildren

What Can We Do About Global Warming? · Recycling saves the energy to

manufacture new products. · Give car a day off by riding a bike, bus,

train or just walking. • Plant trees - they absorb carbon

dioxide. • Read and learn about global warming.

What Can We Do About Global Warming? Save electricity by turning off the TV &

lights when you’re through with them. Use CFLs .

Change five lights.• Go solar - a solar system to provide hot

water can reduce your family’s carbon emissions by about

720 pounds a year.Encourage others to take such actions.

What Can We Do About Global Warming? • Preserve forests - they act as carbon dioxide “sinks” – or they absorb CO2.

• Develop renewable energy technologies to reduce dependence on fossil fuels.

• Use energy more efficiently. For example, the federal government

has initiated a Prime Minister’s Mission of sub-programs with industry to use energy more efficiently & thus reduce

GHG emissions

HAVE A GOOD DAY.