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Greenhouse Gas Emissions and Climate Change

Jürgen ScheffranInstitute of Geography, CliSAP/CEN

Universität Hamburg

“Energy and Climate Policy" Lecture 63-949, June 4, 2015

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Connection between energy and climate impacts

CO2 emissions

CO2 concentration in atmosphere

Global mean temperature

Natural resources

Societal stability and conflict

Energy in production and consumption

Human security risks

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Earth‘s mean annual radiant energy and heat balance:The Greenhouse effect

From Houghton et al. (1996: 58).

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Global carbon cycle

Main annual fluxes in GtC/yr: pre-industrial ‘natural’ fluxes in black and ‘anthropogenic’ fluxes in redIPCC 2007: WG1

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Key terms in climate changeIPCC (2013)

Radiative forcing: change in the net, downward minus upward, radiative flux (expressed in W m–2) at the tropopause or top of atmosphere due to a change in an external driver of climate change

Equilibrium climate sensitivity: equilibrium (steady state) change in the annual global mean surface temperature following a doubling of the atmospheric equivalent carbon dioxide concentration

Global Warming Potential (GWP): Index based on radiative properties of greenhouse gases, measuring the radiative forcing following a pulse emission of a unit mass of a given greenhouse gas in present-day atmosphere integrated over a chosen time horizon, relative to CO2

Climate Feedback Parameter: Way to quantify the radiative response of the climate system to global mean surface temperature change induced by a radiative forcing.

a = (∆Q – ∆F)/∆T, where Q is global mean radiative forcing, T is the global mean air surface temperature, F is heat flux into the ocean and ∆ represents a change

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Global emissions of greenhouse gases

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Greenhouse gas sources, by sector

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Allocation of GHG emissions across sectors

IPCC 2014

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Fossil energy production

Vital Signs 2010

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Global CO2 emissions

CO2 emissions by fuel

Source: Gregor MacDonald, 2010.

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Growing CO2 emissions

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Global anthropogenic greenhouse gas emissions

Source: IPCC 2007: WG-3

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GHG emissions by sector in 1990 and 2004

Source: IPCC 2007: WG-3

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IPCC

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Greenhouse gas emission trends(IPCC 2014)

Total anthropogenic GHG emissions have risen more rapidly from 2000 to 2010 than in the previous three decades (high confidence).

CO2 remains the major anthropogenic GHG with 76% of total GHG emissions in 2010 weighed by GWP100 (high confidence).

Over the last four decades total cumulative CO2 emissions have increased by a factor of 2 from about 900 GtCO2 for the period 1750–1970 to about 2000 GtCO2 for 1750–2010 (high confidence).

Regional patterns of GHG emissions are shifting along with changes in the world economy (high confidence).

Current GHG emission levels are dominated by contributions from the energy supply, Agriculture, Forestry and Other Land‐Use (AFOLU)

Industry and building sectors gain considerably in importance (robust evidence, high agreement).

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Cumulative CO2 emissions have more than doubled since 1970

IPCC 2014

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Total annual anthropogenic GHG emissions by groups of gases 1970-2010

IPCC 2014

p. 18Source: IPCC 2013, WG1

Radiative forcing of climate change during the Industrial Era

p. 19Source: IPCC 2013, WG1

Probability density functions for the effective radiative forcing

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Changes in CO2 concentrations overthe last 1000 years

Source: Anderson/Strahler, Visualizing Weather and Climate

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Global air temperature

Source: Anderson/Strahler, Visualizing Weather and Climate

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Observed and projected climate variables for different IPCC reports

Source: IPCC 2013, AR5-WG1

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Total radiative forcing and cumulative carbon emissions since 1751 in baseline scenario compared to RCP scenarios

IPCC-WG3 (2014)

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Global temperature change and cumulative global CO2 emissions

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Source: IPCC 2013, WG1

Anthropogenic CO2 emissions and partitioning among atmosphere, land & ocean

p. 26Source: IPCC 2013, AR5-WG1

Global mean precipitation versus temperature changes relative to 1986–2005

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Anomalies relative to 1880–1919 for surface temperature, 1960–1980 for ocean heat content, 1979–1999 for sea iceSource: IPCC 2013, WG1

Comparison of observed and simulated climate change

p. 28Anomalies relative to 1880–1919 for surface temperature, 1960–1980 for ocean heat content, 1979–1999 for sea ice

Source: IPCC 2013, WG1

Comparison of observed and simulated climate change

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Observed changes in annual average surface temperature

Source: IPCC 2013, WG1

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Projected changes in annual average surface temperature

Source: IPCC 2013, WG1

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Observed changes in annual average precipitation

Source: IPCC 2013, WG1

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Projected changes in annual average precipitation

Source: IPCC 2014, WG1

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Impact on the hydrological cycle

Multi-model mean changes in components of the water balance (IPCC 2007)

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Impact on biosphere and pedosphere

Multi-model mean changes in (b) frost days [days < 0°C], (d) heat waves [5 conse-cutivedays > Ø + 5°C], (e, f) growing season [days > 5°C] (IPCC 2007) ….

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Projections of climate change-driven biome shiftsin the context of land use

Source: IPCC 2013, AR5-WG1

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Summary of estimated impacts of observed climate changes on yields over 1960–2013

Number of data points analyzed within parentheses for each category (Source: IPCC 2014)

Source: IPCC 2014, WG2

Data points

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Projected risks due to critical climate change impacts on ecosystems

IPCC 2007

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Key terms of climate impacts(IPCC-WG2 2014)

Hazard: Potential occurrence of natural or human-induced physical event, trend or physical impact that may cause loss of life, injury, or other health impacts, damage and loss to property, infrastructure, livelihoods, service provision, ecosystems & environmental resources.

Exposure: Presence of people, livelihoods, species or ecosystems, environmental functions, services, and resources, infrastructure, or economic, social, or cultural assets in places and settings that could be adversely affected.

Vulnerability: Propensity or predisposition to be adversely affected; variety of concepts and elements including sensitivity or susceptibility to harm, lack of capacity to cope and adapt.

Impacts: Effects on natural and human systems, including effects on lives, livelihoods, health, ecosystems, economies, societies, cultures, services, and infrastructure due to the interaction of climate changes or hazardous climate events occurring within a specific time period and the vulnerability of an exposed society or system.

Risk: Potential for consequences where something of value is at stake and where the outcome is uncertain. Risk is often represented as probability of occurrence of hazardous events or trends multiplied by the impacts if these events or trends occur.

Risk = probability x impact

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Global temperature and risks

Source: IPCC 2014, WG2

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Global patterns of impacts in recent decades attributed to climate change

Source: IPCC 2014, WG2

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Risks of tropical storms for urban centers

Source: WBGU 2007

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World Map of the Global Climate Risk Index 1994-2013

Source: Germanwatch and Munich Re NatCatSERVICE Source: Global Climate Risk Index https://germanwatch.org/de/download/10333.pdf

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Vulnerability and risk in climate-society interaction

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Multidimensional vulnerability driven by intersecting dimensions of inequality

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Source: Scheffran/Battaglini 2011

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Climate change risks for human security and the interactions between livelihoods, conflict, culture and migration

Source: IPCC 2014, WG2

p. 47Source: Lenton et al 2008

Tipping elements in the climate system

p. 48Source: IPCC 2013, AR5-WG1

Proportion of global land cover occupied by different land uses

p. 49Source: IPCC 2013, AR5-WG1

Global carbon cycle with typical turnover time scales for carbon transfers through major reservoirs

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Long-term time scales for stabilization

Source: IPCC 2001, Synthesis Report.Source: Intergovernmental Panel on Climate Change, Climate Change 2001: Synthesis Report—Summary for Policymakers. www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr_spm.pdf