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Status and possible solutions to the climate change challenge:

What's new since IPCC AR4?

WMOUNEP

R K PachauriChairman, IPCC

Director-General, TERI

The Ny-Ålesund Symposium8th June 2009

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+2500 scientific expert reviewers

800 contributing authors

450 lead authors

+130 countries

The IPCC Fourth Assessment Report (2007)

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“Warming of the climate system is unequivocal”

- IPCC Fourth Assessment Report

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Observed changes

Global average sea level

Northern hemispheresnow cover

Global average temperature

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Average arctic temperatures increased at almost twice the global average rate in the past 100 years- Annual average arctic sea ice extent has shrunk by 2.7%

per decade

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The frequency of heavy precipitation events has increased over most land areas

- Rainfall in Mumbai (India), 2005: 1 million people lost their homes

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The proportion of tropical cyclones reaching higher intensity have increased over the past 3 decades

- Cyclone Nargis in Myanmar, 2008: 100 000 estimated deaths

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Heat waves have become more frequent over most land areas

- Heat wave in Europe, 2003: 35 000 deaths

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“Continued GHG emissions [...] would induce many changes in the global climate system during the 21st century that would very likely be larger than those observed

during the 20th century”

- IPCC Fourth Assessment Report

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Carbon dioxide emissions

Rad

iati

ve F

orc

ing

(W

m )

Car

bo

n D

ioxi

de

(pp

m)

10000 5000 0

Time (before 2005)

-2Global atmospheric concentrations of greenhouse gases increased markedly as a result of human activities, with an increase of 70% in 1970-2004

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Continued emissions would lead to further warming of 1.1ºC to 6.4ºC over the 21st century

(best estimates: 1.8ºC - 4ºC)

year

Ranges for predicted surface warming

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0 1 2 3 4 5 oC

WATER

Increased water availability in moist tropics and high latitudes

Decreasing water availability and increasing drought in mid-latitudes and semi-arid low latitudes

Hundreds of millions of people exposed to increased water stress

ECO-SYSTEMS

Increased coral bleaching Most corals bleached Widespread coral mortality

Terrestrial biosphere tends towards a net carbon source as: 15% 40% of ecosystems affected

Increasing species range shifts and wildfire risk

Ecosystem changes due to weakening of the meridional overturning circulation

FOOD

Complex, localised negative impacts on small holders, subsistence farmers and fishers

Tendencies for cereal productivity Productivity of all cereals to decrease in low latitudes decreases in low latitudes

Tendencies for some cereal productivity Cereal productivity to decrease in to increase at mid- to high latitudes some regions

COASTS

Increased damage from floods and storms

About 30% of global coastal wetlands lost

Millions more people experience coastal flooding each year

HEALTH

Increasing burden from malnutrition, diarrhoeal, cardio-respiratory, infectious diseases

Increased morbidity and mortality from heat waves, floods, droughts

Changed distribution of some disease vectors

Examples of impacts associated with global average temperature change relative to 1980-1999

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Regions likely to be especially affected

The Arctic, because of the impacts of high rates of warming on natural systems and human communities

Asian and African megadeltas, due to large populations and high exposure to sea level rise, storm surges and river flooding

Small islands, which are highly vulnerable to projected sea level rise

Africa, because of low adaptive capacity and projected climate change impacts

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Negative impacts on Europe

Inland and coastal flooding

Health risks due to heat-waves

Reduction of water availability and crop productivity in South Europe

Species losses and reduced snow cover in mountains

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In the course of the century, water supplies stored in glaciers and snow cover are projected to decline

- The Chacaltaya glacier, 5,300m up in the Andes, which used to be the world's highest ski run, has been reduced to just a few small pieces of ice

1996 2009

Credit: Edson Ramirez

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20-30% of species are likely to be at risk of extinction if increases in warming exceed 1.5-2.5°C

Partial loss of ice sheets on polar land could imply metres of sea level rise, major changes in coastlines and inundation of low-lying areas

Large scale and persistent changes in Meridional Overturning Circulation would have impacts on marine ecosystem productivity, fisheries, ocean CO2 uptake and terrestrial vegetation

Climate change could lead to some abrupt or irreversible impacts

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“Delayed emission reductions significantly constrain the

opportunities to achieve lower stabilisation levels and increase the risk of more severe climate change

impacts”

- IPCC Fourth Assessment Report

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Energy system inertia: delayed emission reductions lead to investments that lock in more emission

intensive infrastructure and development pathways

Climate system inertia: even if GHG concentrations were held constant at year 2000 levels, a further

warming trend would occur in the next two decades at a rate of about 0.1°C per decade

Mitigation actions need to start in the short term in order to have medium- and longer-term benefits

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Stabilisation scenarios

3.2 – 4.0

2.8 – 3.2

2.4 – 2.8

2.0 – 2.4

Global mean temp. increase

(ºC)

2020 – 2060590 – 710

2010 – 2030535 – 590

2000 – 2020490 – 535

2000 – 2015445 – 490

Year CO2 needs to peak

Stabilizationlevel

(ppm CO2-eq)

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Mitigation measures would induce 0.6% gain to 3% decrease of GDP in 2030

Stabilisation levels

(ppm CO2-eq)

Range of GDP reduction

(%)

Reduction of average annual

GDP growth rates

(percentage pts)

445 - 535 < 3 < 0.12

535 - 590 0.2 – 2.5 < 0.1

590 - 710 -0.6 – 1.2 < 0.06

Costs of mitigation in 2030

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“There is substantial […] potential for the mitigation of global GHG

emissions over the coming decades that could […] reduce emissions

below current levels”

- IPCC Fourth Assessment Report

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All stabilisation levels assessed can be achieved by deployment of a portfolio of technologies that are currently available

or expected to be commercialised in coming decades

This assumes appropriate and effective incentives are in place for

their development, acquisition, deployment and diffusion

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Efficient lighting; efficient appliances; improved insulation; solar heating and cooling; alternatives for fluorinated gases in insulation and appliances

Efficiency; fuel switching; renewables; combined heat and power; nuclear power; early applications of CO2 capture & storage

Energy Supply

TransportMore fuel efficient vehicles; hybrid vehicles; biofuels; modal shifts from road transport to rail and public transport systems

Buildings

Key technologies currently available

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Integrated design of commercial buildings including intelligent meters that provide feedback and control; integrated PV

CCS for gas, biomass & coal-fired electricity generating facilities; advanced nuclear power & renewable energy, including tidal and wave energy, concentrating solar, and solar PV

Energy Supply

Transport

2nd generation biofuels; higher efficiency aircraft; advanced electric & hybrid vehicles with more powerful & reliable batteries

Buildings

Technologies expected to be commercialised before 2030

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Regulations and standards

Appropriate energy infrastructure investments

Research, development and demonstration

Key mitigation instruments, policies & practices

Effective carbon-price signal

Taxes and charges

Change in lifestyles & consumption patterns

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Beyond the IPCC Fourth Assessment

Report

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Deeper understanding and quantification of the processes governing the climate system have progressed rapidly since the IPCC First Assessment Report (1990)

The main scientific conclusions from the sequence of IPCC assessments have been refined but not

significantly redirected

Recently observed climate changes remain coherent with the AR4 conclusions, although longer-term observation is required to draw significant conclusions on climate evolutions

Evolution of the climate science

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Research-related priorities

Impacts under different assumptions about future development pathways

Damages avoided by different levels of emissions reduction

Expected impacts at the regional and local level

Causes and thresholds of possible abrupt climate changes

Links between climate change and other policies

Costs of impacts of, and responses to, climate change

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Coming IPCC reports

5th Assessment Report (to be finalised in 2014)

Revised set of scenarios based on possible evolutions of GHG emission trajectories

Deeper coverage of the socio-economic and humanitarian dimensions of climate change

Technical Papers

Special ReportsRenewable energy: 2010Extreme events and disasters: 2011

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Be the change you want to see in the worldDemocracy must in essence therefore, mean the art

and science of mobilizing the entire physical, economics and spiritual resources of all the various sections of the people in the service of the common

good for all.