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Modeling Climate Change in Future Periods (GCM models and Downscaling Techniques). Alireza Massah Bavani , Assistant professor, University of Tehran Iran. Modeling climate change in the future. Climate change study steps. Adaptation to climate change. Impact assessment of climate change.
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Modeling Climate Change in Future Periods (GCM models and Downscaling Techniques) AlirezaMassahBavani, Assistant professor, University of Tehran Iran
Modeling climate change in the future Climate change study steps Adaptation to climate change Impact assessment of climate change Understanding the concepts of climate change Mitigation of climate change
Scio-economic scenario Climate Scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
Scio-economic scenario Climate Scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
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Scio-economic scenario Climate Scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
Monitoring the observed climate (detection of Climate Change) Snow, ice and frozen ground Ocean and Sea Level Atmosphere and surface
Changes in atmosphere and Surface • Global mean surface temperatures have risen by 0.74°C ±0.18°C when estimated by a linear trend over the last 100years (1906–2005). The rate of warming over the last 50 years is almost double that over the last 100 years (0.13°C± 0.03°C vs. 0.07°C ± 0.02°C per decade). • Land regions have warmed at a faster rate than the oceans. • Recent warming is strongly evident at all latitudes in SSTs over each of the oceans.
Average arctic temperatures increased at almost twice the global average rate in the past 100 years. • Precipitation has generally increased over land north of 30°N over the period 1900 to 2005 but downward trends dominate the tropics since the 1970s. • Substantial increases are found in heavy precipitation events. • Droughts have become more common, especially in the tropics and subtropics, since the 1970s. • Tropospheric water vapour is increasing. • Mid-latitude westerly winds have generally increased in both hemispheres.
Changes in cryosphere • The amount of ice on the Earth is decreasing. There has been widespread retreat of mountain glaciers since the end of the 19th century. The rate of mass loss from glaciers and the Greenland Ice Sheet is increasing. • The extent of NH snow cover has declined. Seasonal river and lake ice duration has decreased over the past 150 years. • Since 1978, annual mean arctic sea ice extent has been declining and summer minimum arctic ice extent has decreased. • Temperature at the top of the permafrost layer has increased by up to 3°C since the 1980s in the Arctic.
Ocean and sea level • The global temperature (or heat content) of the oceans has increased since 1955. • Large-scale regionally coherent trends in salinity have been observed over recent decades with freshening in subpolar regions and increased salinity in the shallower parts of the tropics and subtropics. These trends are consistent with changes in precipitation and inferred larger water transport in the atmosphere from low latitudes to high latitudes and from the Atlantic to the Pacific. • Global average sea level rose during the 20th century. There is high confidence that the rate of sea level rise increased between the mid-19th and mid-20th centuries. During 1993 to 2003, sea level rose more rapidly than during 1961 to 2003. • Thermal expansion of the ocean and loss of mass from glaciers and ice caps made substantial contributions to the observed sea level rise. • The observed rate of sea level rise from 1993 to 2003 is consistent with the sum of observed contributions from thermal expansion and loss of land ice. • The rate of sea level change over recent decades has not been geographically uniform. • As a result of uptake of anthropogenic CO2 since 1750, the acidity of the surface ocean has increased.
Scio-economic scenario Climate Scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
What makes Climate Change? Internal forcings External forcings
What makes Climate Change? Internal forcings External forcings
El Niño Southern oscillation Pacific decadal oscillation North Atlantic oscillation Arctic oscillation Thermohaline circulation Some aspect of internal variability
What makes Climate Change? Internal forcings External forcings Internal Variability
Human activities What makes Climate Change? Internal forcings External forcings Internal Variability Natural Orbital Variation Volcanism Solar Variation
External Natural Forcings • Solar Variability
Obliquity (every 41,000 years) • Orbital variation Precession (20,000 years) Eccentricity (every 400,000 years)
Volcanic Eruption • occurs several times per century • causing cooling for a period of a few years, cooling by partially blocking the transmission of solar radiation to the Earth's surface • Huge eruptions, known as large igneous provinces, occur only a few times every hundred million years but can reshape climate for millions of years and cause mass extinctions • most of the dust thrown in the atmosphere returns to the Earth's surface within six months
What makes Climate Change? Internal forcings External forcings Internal Variability Natural Human activities Orbital Variation Volcanism Solar Variation Natural Variability
What makes Climate Change? Internal forcings External forcings Internal Variability Natural Human activities Orbital Variation Volcanism Solar Variation Natural Variability
Land use change (forest, cropland, pasture) Agriculture, Livestock, Deforestation Refrigeration agents Surface Mining, Industrial Process Fossil fuel combustion Aircraft Human Activities CFC-11 CFC-12 CO2,CH4,N2O CO2,N2O Aerosol Change Albedo Change Contrails Greenhouse gasses change Ozone depletion
What makes Climate Change? Internal forcings External forcings Internal Variability Natural Human activities Orbital Variation Volcanism Solar Variation Climate Change Natural Variability
Scio-economic scenario Climate Scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
Scio-economic scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Climate Scenario Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
United Nations Environment Program (UNEP) World Meteorological Organization (WMO) IPCC 1988 1990 –FAR 1995 – SAR 2001 – TAR 2007 – AR4 2013- AR5 Intergovermental Panel of Climate Change (IPCC) WGI WGIII WGII The science of C.C Impact, Adaptation and vulnerability Mitigation
Definitions of terms • Projection: any description of the future and the pathway leading to it. • Forecast/Prediction: When a projection is designated "most likely" it becomes a forecast or prediction • Scenario: A scenario is a coherent, internally consistent and plausible description of a possible future state of the world. It is not a forecast; rather, each scenario is one alternative image of how the future can unfold. A projection may serve as the raw material for a scenario, but scenarios often require additional information (e.g., about baseline conditions). • Baseline/reference: The baseline (or reference) is any datum against which change is measured.
Scio-economic scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Climate Scenario Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
Socio-economic Scenario • Why do we need? • They improve our understanding of the key relationships among factors that drive future emissions. • They provide a realistic range of future emissions of net greenhouse gas and aerosol precursors • They offer a consistent framework of projections that can be applied in climate change impact assessments. • Socio-economic scenarios are projected for the globe up to 2100 and finally convert to emission scenarios
Socio-economic Scenario • Emission scenarios 1- IS92 (1992)
Socio-economic Scenario • Emission scenarios 2- SRES (1998) The four IPCC SRES scenario storylines
Some aspects of the SRES emissions scenarios and their implications
Anthropogenic emissions of CO2, CH4, N2O and sulphur dioxide for the six illustrative SRES scenarios,
Scio-economic scenario Climate Scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
Climate scenario • Criteria for selecting climate scenarios 1: Consistency with global projections. 2: Physical plausibility. 3: Applicability in impact assessments. 4: Representative 5: Accessibility.
Scio-economic scenario Climate Scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
Scio-economic scenario Climate Scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
Use information from the geological record -fossils, sedimentary deposits - to reconstruct past climates 1- the mid-Holocene (5000 to 6000 years BP) - Northern Hemisphere temperatures are estimated to have been about 1°C warmer than today 2- the Last (Eemian) Interglacial (125000 years BP) - about 2°C warmer 3-Pliocene (three to four million years BP) - about 3-4°C warmer palaeoclimate
Disadvantages: • changes in the past unlikely to have been caused by increased GHG concentrations • data and resolution generally insufficient,i.e., extremely unlikely to get daily resolution and individual site information • uncertainty about the quality of palaeoclimatic reconstructions • higher resolution (and most recent) data generally lie at the low end of the range of anticipated future climatic warming
Scio-economic scenario Climate Scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
Scio-economic scenario Climate Scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment
Scio-economic scenario Climate Scenario Modeling climate change in the future The component of climate system Monitoring the observed climate (detection of Climate Change) Synthetic scenarios Analogue scenarios Numerical Models Are the changes unusual? Simple Model (MAGICC Atmospheric-Ocean General Circulation Model (AOGCM) What makes C.C.? Downscaling Attribution of C.C. Impact Assessment