Survey
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
Download Diocesan Environment Advisor
Document related concepts
no text concepts found
Transcript
Climate change Revd Professor Ian James Head of School of Mathematics, Meteorology & Physics, University of Reading Oxford Diocesan environment advisor [email protected] Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Plan of talk • The problem • Is climate change real? • Some complications • The future Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] The problem - why climate change is a concern Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Atmospheric carbon dioxide Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] A little goes a long way! Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Two views of Earth Visible light Ian James Infra-red view Diocese of Oxford Environment Advisor E-mail . [email protected] The “greenhouse” effect • Carbon dioxide blankets Earth’s surface. • Sunlight gets in. • Infra-red absorbed and reemitted. • Other greenhouse agents – water vapour, clouds. Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Carbon dioxide & ice ages Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] The carbon cycle • Fossil fuels (coal, oil, natural gas) are made of carbon and hydrogen. • When burnt, they produce energy, water and carbon dioxide. Ian James Human Natural Diocese of Oxford Environment Advisor E-mail . [email protected] What activities generate carbon dioxide? • All sources are comparable • No easy target! • Reduction across the board Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Is climate change happening? Some examples Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Variations of the Earth’s surface temperature for the past 1,000 years SPM 1b Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Summer 2003 Temperature Anomaly June-August 2003 Deviation from 1961-1990 mean Based on ECMWF and ERA-40 Color: temperature anomaly ºC Contours: normalized by standard deviation Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] (Schär et al. 2004, Nature, 427, 332-336) Hurricanes •More intense •More extremes •Form over hottest sea Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Arctic sea ice September 1979 Ian James September 2005 Diocese of Oxford Environment Advisor E-mail . [email protected] Glaciers in retreat Pasterze glacier, Austria, 1875 Ian James Same view, 2004 Diocese of Oxford Environment Advisor E-mail . [email protected] Sea-level transgression scenarios for Bangladesh Adapted from Milliman et al. (1989). Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Some complications…. Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Feedbacks…… A positive feedback loop… Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Examples of climate feedbacks • Warm atmosphere becomes moister • Melting ice & snow makes surface darker • Melting tundra releases methane • Moist atmosphere becomes cloudier Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Melting permafrost • Vast areas of the high northern latitudes have permanently frozen soils – “tundra”. • These are thawing out as warming accelerates • Thawing releases methane • Methane is an even more potent greenhouse gas than carbon dioxide Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] The “tipping point” • The point at which carbon dioxide levels are so high enough that feedbacks take over, and changes become irreversible. • Are we approaching a “tipping point”? Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] The future? Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Global carbon emissions from fossil fuels Ian James Diocese of Oxford Environment Advisor E-mail . [email protected] Only connect! • Interdependence of natural world • We are part of natural world! • Need to live sustainably within the entire world community Ian James Diocese of Oxford Environment Advisor E-mail . [email protected]
Related documents