Changes in precipitation and water Changes in precipitation and water in the Americas in the Americas with climate change with climate change Kevin E Trenberth Kevin E Trenberth NCAR NCAR Thanks to Ray Bradley Thanks to Ray Bradley
Global temperature and carbon dioxide: Global temperature and carbon dioxide: anomalies through 2010 anomalies through 2010 Base period 1900-99; data from NOAA
How should precipitation change How should precipitation change as climate changes? as climate changes? Usually only total amount is considered Usually only total amount is considered • But most of the time it does not rain • But most of the time it does not rain • The frequency and duration (how often) • The frequency and duration (how often) • The intensity (the rate when it does rain) • The intensity (the rate when it does rain) • The sequence • The sequence sequence • The phase • The phase : snow or rain phase : snow or rain The intensity and phase affect The intensity and phase affect how much runs off versus how how much runs off versus how much soaks into the soils. much soaks into the soils.
Most precipitation comes from moisture Most precipitation comes from moisture convergence by weather systems convergence by weather systems Rain comes from moisture convergence by low level winds: More moisture means heavier rains
Land precipitation is changing significantly over broad areas Land precipitation is changing significantly over broad areas Increases Decreases Smoothed annual anomalies for precipitation (%) over land from 1900 to 2005; other regions are dominated by variability. IPCC
Precipitation Precipitation Observed trends Observed trends (%) per decade (%) per decade for 1951–2003 for 1951–2003 contribution to contribution to total annual from total annual from very wet days very wet days > 95th %ile. > 95th %ile. Alexander et al 2006 Alexander et al 2006 IPCC AR4 IPCC AR4 Heavy precipitation days are increasing even in Heavy precipitation days are increasing even in places where precipitation is decreasing. places where precipitation is decreasing.
Drought is increasing most places Drought is increasing most places The most The most Mainly decrease in rain important spatial important spatial over land in tropics and pattern (top) of pattern (top) of subtropics, but enhanced the monthly the monthly by increased atmospheric Palmer Drought Palmer Drought demand with warming Severity Index Severity Index (PDSI) for 1900 (PDSI) for 1900 to 2002. to 2002. The time series The time series (below) accounts (below) accounts for most of the for most of the trend in PDSI. trend in PDSI. Dai et al 2004 IPCC 2007
Glaciers are retreating around the world Change in length and area of 10 tropical Andean glaciers Ecuador Peru Bolivia Source: Francou & Vincent, 2007
Glaciers will continue to melt! Projected change in temperature* (1990-99) to (2090-99) along the American Cordillera, from Alaska to Chile Mountain peaks Limited data Limited data South North *Mean of 8 GCM simulations from IPCC 4 th Assessment using scenario A2 Source: Bradley et al., 2006
The cost of glacier recession The cost of glacier recession • Energy Andean countries depend on hydropower generation Bolivia 50% Colombia 73% Ecuador 72% Peru 81% • Water for urban areas – Quito, La Paz, Lima & other cities – (Bogota, Quito depend equally on paramo-derived water) • Agriculture – Changes in seasonality of runoff affect irrigation, crop types etc
GARP 0102 “Introduction to Physical Geography” Lecture 1 (Wednesday, 01/21/09) Jan 2009 Jan 2009 Pico Humboldt, Venezuelan Andes Pico Humboldt, Venezuelan Andes Photo: Carsten Braun Spring 1934 (Kern, 1937) Spring 1934 (Kern, 1937) Photo: Carsten Braun
GARP 0102 “Introduction to Physical Geography” Lecture 1 (Wednesday, 01/21/09) Jan 2009 Jan 2009 Pico Humboldt, Venezuelan Andes Pico Humboldt, Venezuelan Andes 4942m 4680m 1952: 4500m 1934: 4300?m Spring 1934 (Kern, 1937) Spring 1934 (Kern, 1937) Ice margin was ~200m lower in 1952, Photo: Carsten Braun even lower in 1934 (inset)
Nevado de Santa Isabel, Colombia de Santa Isabel, Colombia Nevado 44% mass loss Ruiz: 5320m Santa Isabel: 4965m Tolima: 5215m Sources: J. Ramírez Cadena & GRID ‐ ARENAL, UNEP
Cotopaxi, Ecuador (5897m) Mean loss in glacier area, 1976 ‐ 1997: 30% Photo: Dave Semler and Marsha Steffen Source: Jordan et al., 2005
Qori Kalis Kalis glacier, glacier, Quelccaya Quelccaya Ice Cap, Peru: June, 2007 Ice Cap, Peru: June, 2007 Qori
2009
Model predictions Model predictions “Rich get richer, poor get poorer” “Rich get richer, poor get poorer” Projections: Wet get wetter; dry get drier. Combined effects of increased precipitation intensity, more dry days, and stronger evaporation contribute to lower soil moisture 2090-2100 IPCC
Conclusions: Conclusions: The need for environmental justice The need for environmental justice 1. Global warming increases temperatures and water vapor 2. It directly changes precipitation: more intense; longer dry spells; shorter snow season, less snow pack 3. Rich get richer, poor get poorer; but patterns complex 4. Greater risk of flooding and droughts 5. Temperatures are rising—globally & across S. America 6. High elevations are being affected—glaciers are melting 7. Future warming will be greater at high elevations 8. Seasonal changes in river flow can be expected 9. All regions are affected, some more than others, and regardless of whether they contributed to the problem 10.Water management will be major challenge in the future
Climate and Earth System observations and models will contribute to environmental justice by assessing the impacts of climate change on food production, flooding, drought, sea level rise, and health. Who is going to be most affected by climate change? From Istockphoto.com
Comunidad Khapi y el Illimani Comunidad Khapi y el Illimani Alivio Aruquipa Aruquipa Lazo Lazo Alivio
1920 2008
¿Nuestro Futuro? Nuestro Futuro? ¿
Human Rights Implications of Climate-Induced Threats to Access to Freshwater Martin Wagner Managing Attorney, International Program mwagner@earthjustice.org
Other Climate Impacts on Access to Water Saltwater Intrusion Drought Flooding
The Right to Water 1920 2008 Climate change will, and already does, impact on people’s rights to water and sanitation by causing floods and droughts, changes in precipitation and temperature extremes that result in water scarcity, contamination of drinking water and exacerbation of the spread of disease. - UN Independent Expert
The Right to Water • Inter-American Court of Human Rights. Access to a sufficient quantity of adequate quality freshwater is essential to realization of the right to a life of dignity. (Caso Communidad Indígena Xákmok Kásek v. Paraguay (2010), ¶¶ 196, 217) • UN General Assembly. “The right to safe and clean drinking water and sanitation [is] a human right that is essential for the full enjoyment of life and all human rights.” (The Human Right to Water and Sanitation, Resolution 64/292, July 2010) • UN Human Rights Conventions – Committee on Econ., Soc., Cultural Rights. “The human right to water entitles everyone to sufficient, safe, acceptable, physically accessible and affordable water for personal and domestic uses.” (General Comment No. 15, “The Right to Water” (2002)) – CEDAW, Art. 14. Women have the right to “enjoy adequate living conditions, particularly in relation to … water supply” – Convention on the Rights of the Child, Art. 24. Right to attain highest standard of health requires “the provision of adequate … and clean drinking- water.”
Some Other Rights Affected by Climate-Induced Changes to Freshwater Resources • Right to life • Right to health and sanitation • Right to food and means of subsistence • Rights of indigenous and other resource-dependent peoples to enjoy the benefits of their culture , and to use and enjoy the lands they have traditionally used and occupied .
Climate Change and Human Rights UN Human Rights Council resolution 10/4 (2009) – “[C]limate change-related impacts have a range of implications, both direct and indirect, for the effective enjoyment of human rights including … obligations related to access to safe drinking water and sanitation.” OHCHR, Report on the Relationship between Climate Change and Human Rights – “[G]lobal warming will potentially have implications for the full range of human rights.” – “Climate change will ... exacerbate existing stresses on water resources and compound the problem of access to safe drinking water.”
Recommend
More recommend
