680 likes | 911 Vues
Climate change: Challenge, menace or opportunity?. Extreme events and climate change Climate change and human action Built vulnerability as the local expression of unmanaged risk.
E N D
Climate change:Challenge, menace or opportunity? Extreme events and climate change Climate change and human action Built vulnerability as the local expression of unmanaged risk
Built vulnerability: human intervention increases exposure to extreme events. Climate change is an additional stress for sustainable, resilient development
Increased climate change is insufficiently valued in its costs
The results of the 4th Assessment report to the IPCC (why was it given the 2007 half of the Peace Nobel Prize) Essential conclusions of the three working groups: • Group I: incontestable evidence of climate change and its attribution to human intervention linking greenhouse gases to climate change. • Group II: Impacts are undeniable and can be traced as additional stress sustainable development. Local impacts are aggravated by development, physical and structural vulnerabilites. Adaptation costs are smaller than damage and losses, as demonstrated by extreme events increase over time. • Group II: Overal dynamic impact of mitigation (as decreased growth or higher sustainable development investment) is smaller than cost of unabated continuation of tendencies (3% decrease of world GDP growth associated to mitigation to avoid 30% loss of GDP in next 30/5o years. • Need for both local and global efforts, concentrating developing countries efforts in adaptation supported by developed and emerging economies efforts in mitigation. • Sound scientific and technical basis for crucial Bali negotiations of Post-Kyoto convention. Relevant participation of developing countries’ scientists and researchers in AR4: as lead authors and as literature quoted, focusing on differentiated regional impacts: the case for SIDS
Regional impact in Latin America and the Caribbean (see also the small Islands chapter)
The climate record from the Vostok (Antarctica) ice core shows the natural variations in the atmospheric CO2 levels associated with the swing between full glacial conditions and interglacial periods such as today. Note the 1994 atmospheric CO2 level plotted on the left-hand side of the graph; we currently have an unusually high concentration of carbon dioxide. The climatological effects are thus potentially significant.
Cambio climático y efectos sobre trayectoria de tormentas y patrones estacionales temperatura Fuerza de actividades antrópicas contribuye al cambio climático Circulación del aire: Cambios recientes
GLACIER MELTDOWN Evolution of area and volume of the Chacaltaya glacier (Bolivia), as estimated by Soruco et al. 2005 • Temperature variation, where both the maximum and minimum increase, has affected the Andean glaciers, showing a marked recess in terms of extension and volume. • Up to 40% reduction linked to atmospheric temperature increase. • Mos notable recessions: Campos de hielo Sur (Chile- Argentina), Callejón del Huaylas (Perú), Cordillera Real (Bolivia) • Threat to livelihood in the Andean valleys (water sources, avalanches, watersheds)
Is there still a controversy? • Although some meteorologists say historical series have to be adjusted for the longer trend • All scenarios show that since the mid 19th century the level of temperature rise is increasing constantly
What is the expected impact on climate? Change in global surface temperature Change in global mean sea level
Pattern of annual average temperature change, 2080s relative to present day for A1F1 (left) and B2 (right) emissions scenarios
Precipitation indices: maximum length of dry spell per year (2070-99 minus 1961-90) • A2a: • Longer by 15-30 days in centre and south east • 10 days shorter over northern Europe A2a A2a scenario • B2a: • Smaller changes than A2a • wetter Eastern Med. B2a
Hurricanes in the Atlantic have increased (in frequency and strength) with the sea level temperature rise (SST) Notable increase after 1944 (1944-2005) SST
Probability of extreme events: Atlantic Tropical Cyclone Frequency 2006-2010:An Experimental Forecast Based on Multi-decadal Analogues, JORGE SÁNCHEZ–SESMA,Coordinación de Hidrología, Instituto Mexicano de Tecnología del Agua, Morelos, México.
Precipitation indices: max. 5-day running total(2070-99 minus 1961-90) • A2a: • Lower intensity, by 10-20 mm, in future, particularly in west • Increased intensity in centre and Adriatic A2a scenario • B2a: • Smaller changes than A2a • Clearly higher intensity in Italy
Impacts • Impacts of more intense rainfall on storm drains/sewers • Heat stress • Changes in circulation and the implications for air pollution • Coastal cities and tidal surge • Implications of increased wind storm
Adaptation • Through design: • Of urban spaces • Of buildings • Land use planning • Development poverty reduction and adaptation • Through behaviour • Use of the outdoor environment • Transport policies • Air conditioning
Mitigation activities • Energy use • Reduction in demand • Use of renewables • Fuel-efficient transport systems • Clean production procedures • Aforestation and reforestation • Saved deforestation (to be obtained in new Post-Koto negotiations)
What about surprises/abrupt climate change? • Collapse of the West Antarctic Ice Sheet • Melting of the Greenland ice cap • Collapse of the North Atlantic thermohaline circulation • Of course, the real surprises are the ones we haven’t thought of
The Inter-governmental Panel on Climate Change • To assess the scientific literature on climate change • To support the UNFCCC • Three Working Groups • Science • Impacts, Adaptation and Vulnerability • Mitigation and Policy • Now carrying out the Fourth Assessment • To report in 2007
Structure of WGII • Two Co-Chairs: • Martin Parry, UK • Osvaldo Canziani, Argentina • Six Vice-Chairs • One TSU with four full-time staff • Writing team of around 200 CLAs, LAs and REs, plus Contributing Authors • Four Lead Author Meetings
Working Group II AR4 Summary for Policymakers + Technical Summary Introduction 1. Assessment of observed changes and responses in natural and managed systems II. ASSESSMENT OF FUTURE IMPACTS AND ADAPTATION: SECTORS 2. New assessment methodologies and the characterisation of future conditions 3. Fresh water resources and their management 4. Ecosystems, their properties, goods and services 5. Food, fibre and forest products 6. Coastal systems and low-lying areas 7. Industry, settlement, and society 8. Human health III. ASSESSMENT OF FUTURE IMPACTS AND ADAPTATION: REGIONS 9: Africa, 10: Asia, 11: Australia and New Zealand, 12: Europe, 13: Latin America 14: North America, 15: Polar Regions (Arctic and Antarctic), 16: Small Islands IV. ASSESSMENT OF RESPONSES 17. Assessment of adaptation practices, options, constraints and capacity 18. Inter-relationships between adaptation and mitigation 19. Assessing key vulnerabilities and the risk from climate change 20. Perspectives on climate change and sustainability
The IPCC Fourth Assessment Working Group Reports:Key findings WMO UNEP Dr R K Pachauri Chairman, IPCC Director-General, TERI United Nations Headquarters New York City 24th September 2007
Changes in CO2 from ice core and modern data -2 Radiative Forcing (Wm ) Carbon Dioxide (ppm) Human contribution to climate change Global atmospheric concentrations of greenhouse gases increased markedly as result of human activities In 2005 concentration of CO2exceeded by far the natural range over the last 650,000 years 10000 5000 0 Time (before 2005)
Changes in temperature, sea level and northern hemisphere snow cover Global average temperature Global average sea level Northern hemisphere snow cover Direct observations of recent climate change
Cumulative balance of glacier mass in some regions Glacier mass balance During the 20th century, glaciers and ice caps have experienced widespread mass losses and have contributed to sea level rise Further decline of mountain glaciers projected to reduce water availabilityin many regions
Key vulnerabilities to climate change • Some regionswill be more affected than others: • The Arctic (ice sheet loss, ecosystem changes) • Sub-Saharan Africa (water stress, reduced crops) • Small islands (coastal erosion, inundation) • Asian mega-deltas (flooding from sea and rivers) • Some ecosystemsare highly vulnerable: • Coral reefs, marine shell organisms • Tundra, boreal forests, mountain and Mediterranean regions • 20-30% of plant and animal species at risk of extinction