CLIM 101 Weather Climate and Global Society Projected

CLIM 101: Weather, Climate and Global Society Projected Global Changes Jagadish Shukla Lecture 17: Oct 28, 2008 Center of Ocean-Land. Atmosphere studies

1. The IPCC 4 th Assessment 2. “Intergovernmental” Assessment—is it an “Integrated assessment? ” Every 5 (or so) years The Process: WG 1, 2, 3 and the Synthesis Document. Reviews, SPM “Policy relevant but not policy prescriptive” The FCCC (1992) is the policy mechanism of the UN

FCCC OBJECTIVE (1992) “The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner. ”

PRINCIPLES 1. The Parties should protect the climate system for the benefit of present and future generations of humankind, on the basis of equity and in accordance with their common but differentiated responsibilities and respective capabilities. Accordingly, the developed country Parties should take the lead in combating climate change and the adverse effects thereof. 2. The specific needs and special circumstances of developing country Parties, especially those that are particularly vulnerable to the adverse effects of climate change, and of those Parties, especially developing country Parties, that would have to bear a disproportionate or abnormal burden under the Convention, should be given full consideration.

PRINCIPLES 3. The Parties should take precautionary measures to anticipate, prevent or minimize the causes of climate change and mitigate its adverse effects. Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing such measures, taking into account that policies and measures to deal with climate change should be cost-effective so as to ensure global benefits at the lowest possible cost. To achieve this, such policies and measures should take into account different socioeconomic contexts, be comprehensive, cover all relevant sources, sinks and reservoirs of greenhouse gases and adaptation, and comprise all economic sectors. Efforts to address climate change may be carried out cooperatively by interested Parties.

PRINCIPLES 4. The Parties have a right to, and should, promote sustainable development. Policies and measures to protect the climate system against human-induced change should be appropriate for the specific conditions of each Party and should be integrated with national development programmes, taking into account that economic development is essential for adopting measures to address climate change. 5. The Parties should cooperate to promote a supportive and open international economic system that would lead to sustainable economic growth and development in all Parties, particularly developing country Parties, thus enabling them better to address the problems of climate change. Measures taken to combat climate change, including unilateral ones, should not constitute a means of arbitrary or unjustifiable discrimination or a disguised restriction on international trade.

IMPLEMENTATION: 2. The head of the interim secretariat referred to in paragraph 1 above will cooperate closely with the Intergovernmental Panel on Climate Change to ensure that the Panel can respond to the need for objective scientific and technical advice. Other relevant scientific bodies could also be consulted

The Issue of “predictions” The SRES: The Emission Scenarios of the IPCC Special Report on Emission Scenarios A 1. The A 1 storyline and scenario family describes a future world of very rapid economic growth, global population that peaks in mid-century and declines thereafter, and the rapid introduction of new and more efficient technologies. Major underlying themes are convergence among regions, capacity building and increased cultural and social interactions, with a substantial reduction in regional differences in per capita income. The A 1 scenario family develops into three groups that describe alternative directions of technological change in the energy system. The three A 1 groups are distinguished by their technological emphasis: fossil intensive (A 1 FI), non-fossil energy sources (A 1 T), or a balance across all sources (A 1 B) (where balanced is defined as not relying too heavily on one particular energy source, on the assumption that similar improvement rates apply to all energy supply and end use technologies). A 2. The A 2 storyline and scenario family describes a very heterogeneous world. The underlying theme is self reliance and preservation of local identities. Fertility patterns across regions converge very slowly, which results in continuously increasing population. Economic development is primarily regionally oriented and per capita economic growth and technological change more fragmented and slower than other storylines.

The Issue of “predictions” The SRES: The Emission Scenarios of the IPCC Special Report on Emission Scenarios B 1. The B 1 storyline and scenario family describes a convergent world with the same global population, that peaks in mid-century and declines thereafter, as in the A 1 storyline, but with rapid change in economic structures toward a service and information economy, with reductions in material intensity and the introduction of clean and resource efficient technologies. The emphasis is on global solutions to economic, social and environmental sustainability, including improved equity, but without additional climate initiatives. B 2. The B 2 storyline and scenario family describes a world in which the emphasis is on local solutions to economic, social and environmental sustainability. It is a world with continuously increasing global population, at a rate lower than A 2, intermediate levels of economic development, and less rapid and more diverse technological change than in the B 1 and A 1 storylines. While the scenario is also oriented towards environmental protection and social equity, it focuses on local and regional levels. An illustrative scenario was chosen for each of the six scenario groups A 1 B, A 1 FI, A 1 T, A 2, B 1 and B 2. All should be considered equally sound. The SRES scenarios do not include additional climate initiatives, which means that no scenarios are included that explicitly assume implementation of the United Nations Framework Convention on Climate Change or the emissions targets of the Kyoto Protocol.

Anthropogenic Global Carbon Cycle No slow down of emission in sight! Uncertainties are being reduced fossil fuel emissions tropical deforestation atmospheric CO 2 ocean sink Error analysis: FF + other emissions: 0. 3 Pg. C/y Land Use change: 1. 0 Pg. C/y Atmospheric increase: 0. 1 Pg. C/y Ocean uptake: 0. 5 Pg. C/y Residual Land use: 1. 2 Pg. C/y Atmospheric accumulation = FFoss + FLUC + FLand. Air + FOcean. Air Source: Pep Canadell, Corinne Le. Quere, Mike Raupach, Gregg Marland, Skee Houghton, Tom Conway, Philippe Ciais, GCP, 2006. land sink

Global temperature changes estimated for SRES (bottom) and stabilisation (top)

Intergovernmental Panel on Climate Change (IPCC) IPCC has been established by WMO and UNEP to assess scientific, technical and socio- economic information relevant for the understanding of climate change, its potential impacts and options for adaptation and mitigation. Working Group I: The Physical Science Basis Working Group II: Impacts, Adaptation and Vulnerability Working Group III: Mitigation of Climate Change • Largest number of U. S. scientists: nominated by the U. S. Govt. • Highest skepticism : “U. S. Govt. ” Center of Ocean-Land. Atmosphere studies

What is a Model? • Quantitative and/or qualitative representation of natural processes (may be physical or mathematical) • Based on theory • Suitable for testing “What if…? ” hypotheses • Capable of making predictions Center of Ocean-Land. Atmosphere studies

What is a Model? Input Data Model What input data might we consider for a typical climate model? Output Data What output data might we consider for a typical climate model? Tunable Parameters Center of Ocean-Land. Atmosphere studies What are the tunable parameters of interest?

Climate System Modeling Atmospheric General Circulation Model Physical processes Basic Equations Dynamics

Using the secant approach, we can approximate the temperature equation: By reducing t, we can obtain an increasingly accurate solution.

Ω CLIMATE DYNAMICS OF THE PLANET EARTH g S a (albedo) T 4 O 3 S, H 2 O , a, g, Ω CO 2 h*: mountains, oceans (SST) w*: forest, desert (soil wetness) stationary waves (Q, h*), monsoons hydrodynamic instabilities of shear flows; stratification & rotation; moist thermodynamics day-to-day weather fluctuations; wavelike motions: wavelength, period, amplitude W E A T H E R C L I M A T E.

What is a Climate Model? • Equations of motions and laws of thermodynamics to predict rate of change of: T, P, V, q, etc. (A, O, L, CO 2, etc. ) • 10 Million Equations: 100, 000 Points × 100 Levels × 10 Variables • With Time Steps of: ~ 10 Minutes • Use Supercomputers

• Geographic resolution characteristic of the generations of climate models used in the IPCC Assessment Reports: FAR (IPCC, 1990), SAR (IPCC, 1996), TAR (IPCC, 2001 a), and AR 4 (2007). • The figures above show successive generations of these global models increasingly resolved northern Europe. These illustrations are representative of the most detailed horizontal resolution used for short-term climate simulations. • The century-long simulations cited in IPCC Assessment Reports after the FAR were typically run with the previous generation’s resolution. Vertical resolution in both atmosphere and ocean models is not shown, but it has increased comparably with the horizontal resolution, beginning typically with a singlelayer slab ocean and ten atmospheric layers in the FAR and progressing to about thirty levels in both atmosphere and ocean.

(Net) Global Warming 1. Greenhouse gases (CO 2, CH 4, N 2 O) • • • CO 2: Carbon Dioxide : Emission from fossil fuel CH 4: Methane : Agriculture N 2 O: Nitrous Oxide 2. Land use change Cooling 1. Aerosols • • Man made/Natural Volcanoes ※Rate of increase of GHG is largest in 10, 000 years Center of Ocean-Land. Atmosphere studies

Global mean, volume mean ocean temperature Courtesy of Tom Delworth (GFDL) GFDL Model Simulations

Global and Continental Temperature Change Comparison of observed continental- and global-scale changes in surface temperature with results simulated by climate models using natural and anthropogenic forcings. Decadal averages of observations are shown for he period 1906 -2005 (black line) plotted against the centre of the decade and relative to the corresponding average for 1901 -1950. Lines are dashed where spatial coverage is less than 50 %. Blue shaded bands show the 5 -95% range for 19 simulates form 5 climate models using only the natural forcings due to solar activity and volcanoes. Center of Ocean-Land. Red shaded bands show the Atmosphere studies for 58 simulations from 14 climate models using both natural and 5 -95% range anthropogenic forcings.

Main threat to a sustainable Earth IPCC-AR 4: Warming of the climate system is unequivocal

Mean of 15 Models Surface Air Temperature Difference (Sresa 1 b YR 71 -100) minus (20 c 3 m 1969 -98), Global Average = 2. 61 Center of Ocean-Land. Atmosphere studies

1. 0º C Courtesy of UCAR Center of Ocean-Land. Atmosphere studies

Multi-Model Means of Surface Warming Figure 10. 4 Center of Ocean-Land. Atmosphere studies

Global Mean Surface Warming and Precipitation Center of Ocean-Land. Atmosphere studies

Multi-Model Means of Surface Warming Center of Ocean-Land. Atmosphere studies

Multi-Model Mean Changes of Surface Air Temperature, Precipitation and Sea Level Pressure Center of Ocean-Land. Atmosphere studies

Multi-Model Mean Changes in SRES A 1 B (2080 to 2099 minus 1980 to 1999) Center of Ocean-Land. Atmosphere studies

Multi-Model Anomalies in Sea Ice Extent Center of Ocean-Land. Atmosphere studies

Multi-Model Mean Sea Ice Concentration (SRES A 1 B scenario) Center of Ocean-Land. Atmosphere studies

Changes in Extremes in Multi-Model Simulations Center of Ocean-Land. Atmosphere studies

Projected CO 2 emissions Center of Ocean-Land. Atmosphere studies

Multi-Model Mean of Projected Levels of Saturation Center of Ocean-Land. Atmosphere studies

Probability Density Function for Global Mean Temperature Changes Center of Ocean-Land. Atmosphere studies

Evolution of Greenland Surface Elevation and Ice Sheet Volume Center of Ocean-Land. Atmosphere studies

Mean of 15 Models Surface Air Temperature Difference (Sresa 1 b YR 71 -100) minus (20 c 3 m 1969 -98), Global Average = 2. 61 Center of Ocean-Land. Atmosphere studies

Climate Model Fidelity and Projections of Climate Change J. Shukla, T. Del. Sole, M. Fennessy, J. Kinter and D. Paolino Geophys. Research Letters, 33, doi 10. 1029/2005 GL 025579, 2006 Center of Ocean-Land. Atmosphere studies

Main threat to a sustainable Earth • Arctic summer sea ice likely to disappear in second half of century • Dynamic instability of Greenland ice sheets • Very likely increase in heat waves • Likely increase in intensity of tropical storms • Etc… SST

Main threat to a sustainable Earth • Damages from business-as-usual scenario would be at least 5% and up to 20% of Global GDP a year • Costs of removing most of the climate risk are around 1% of GDP per year • This is equivalent to paying on average 1% more for what we buy • “We can grow and be green” Sir Nicholas Stern

Main threat to a sustainable Earth Trajectories towards stabilization levels (ppm CO 2 -eq) Median GDP reduction (%) Range of GDP reduction (%) Reduction of average annual GDP growth rates (percentage points) 590 -710 0. 2 -0. 6 – 1. 2 < 0. 06 535 -590 0. 6 0. 2 – 2. 5 <0. 1 Not available <3 < 0. 12 445 -535 • According to IPCC AR 4/WGIII, the cost of avoiding the worst would be only a fraction of what Stern Report projected

Sustainability issues – LDCs • China, India and Brazil: now among the main drivers of the world’s economy China’s GDP has grown on average 9. 6% per year in the last quarter century China replaced EU as the main importer of Brazilian soybeans Nepstad et al. , Conservation Biology (2006)

Sustainability issues – LDCs Economic losses due to pollution in China amounted to US$ 12. 8 billion annually – 1. 4% of GDP (1990 -1998) • Cultivated land area went from 1, 307, 400 km² in 1991 to 1, 282, 400 km² in 2000 • Construction accounted for 56. 6% of reduction • 60% of China’s 669 cities face water scarcity Source: Gaoming Jiang & Jixi Gao, 2007

Sustainability issues - LDCs • 2006: 2. 6% increase in global CO 2 from fossil fuel • Mainly due to 4. 5% increase in coal consumption • China contributed more than two-thirds • China’s CO 2 emissions surpassed those of the USA by 8% LDCs are now part of the problem and part of the solution Total emissions

Sustainability issues - LDCs Per capita emissions US China But LDCs: small contribution to climate change, at least in per capita terms Remember 1992 UNFCCC: “Common but differentiated responsibilities”

Equality: impacts will hit the poor hardest and earliest

Impacts hit the poor hardest • 30 to 200 million people at risk of hunger with temperature rises of 2 to 3°C • 0. 7 to 4. 4 billion people will experience growing water shortages with a rise of 2°C Yields across Africa and Western Asia may fall by 15% to 35%

Impacts hit the poor hardest Climate impacts will decrease water availability and drought in semi-arid latitudes “It’s exactly what we don’t want; it makes the world much less even, more inequitable” Martin Parry, co-chair IPCC WGII

Challenges to be addressed ECOSYSTEM SERVICES • • • Purification of air and water Mitigation of droughts and floods Preservation of soils Pollination of crops and vegetation Dispersal of seeds • • • Cycling and movement of nutrients Control of potential agricultural pests Maintenance of biodiversity Protection of coastal shores erosion Stabilization of climate etc.

Sustainability issues – LDCs • Under threat: Cerrado, Brazilian savanna • One of Brazil’s two biodiversity hotspots • At the current rate of loss, gone by 2030 CI/Nature

Impacts hit the poor hardest • Adaptation will cost LDCs $10 bns anually • Even more for the necessary infrastructure

Main threat to a sustainable Earth

Impacts hit the poor hardest • Nearly 200 million people live in coastal flood zones at risk • South Asia alone: more than 60 million people Source: Gordon et al. , 2004

THANK YOU! ANY QUESTIONS? Center of Ocean-Land. Atmosphere studies