Changes in precipitation and water in the Americas with climate change. Kevin E Trenberth NCAR. Thanks to Ray Bradley

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1 Changes in precipitation and water in the Americas with climate change Kevin E Trenberth NCAR Thanks to Ray Bradley

2 Global temperature and carbon dioxide: anomalies through 2010 Base period ; data from NOAA

3 How should precipitation change as climate changes? Usually only total amount is considered But most of the time it does not rain The frequency and duration (how often) The intensity (the rate when it does rain) The sequence The phase: snow or rain The intensity and phase affect how much runs off versus how much soaks into the soils.

4 Most precipitation comes from moisture convergence by weather systems Rain comes from moisture convergence by low level winds: More moisture means heavier rains

5 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

6 Precipitation Observed trends (%) per decade for contribution to total annual from very wet days > 95th %ile. Alexander et al 2006 IPCC AR4 Heavy precipitation days are increasing even in places where precipitation is decreasing.

7 Drought is increasing most places Mainly decrease The most in rain over land important in tropics spatial and subtropics, pattern but enhanced (top) of by increased the atmospheric monthly demand Palmer with warming Drought Severity Index (PDSI) for 1900 to The time series (below) accounts for most of the trend in PDSI. Dai et al 2004 IPCC 2007

8 Glaciers are retreating around the world Change in length and area of 10 tropical Andean glaciers Ecuador Peru Bolivia Source: Francou & Vincent, 2007

9 Glaciers will continue to melt! Projected change in temperature* ( ) to ( ) 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

10 Energy The cost of glacier recession 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

11 GARP 0102 Introduction to Physical Geography Lecture 1 (Wednesday, 01/21/09) Jan 2009 Pico Humboldt, Venezuelan Andes Photo: Carsten Braun Spring 1934 (Kern, 1937) Photo: Carsten Braun

12 GARP 0102 Introduction to Physical Geography Lecture 1 (Wednesday, 01/21/09) Jan 2009 Pico Humboldt, Venezuelan Andes 4942m 4680m 1952: 4500m 1934: 4300?m Ice margin was ~200m lower in 1952, even Photo: lower Carsten in 1934 (inset) Braun Spring 1934 (Kern, 1937)

13 Nevado de Santa Isabel, Colombia 44% mass loss Ruiz: 5320m Santa Isabel: 4965m Tolima: 5215m Sources: J. Ramírez Cadena & GRID ARENAL, UNEP

14 Cotopaxi, Ecuador (5897m) Mean loss in glacier area, : 30% Photo: Dave Semler and Marsha Steffen Source: Jordan et al., 2005

15 Qori Kalis glacier, Quelccaya Ice Cap, Peru: June, 2007

16 2009

17 Model predictions 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 IPCC

18 Conclusions: 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

19 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

20 Comunidad Khapi y el Illimani Alivio Aruquipa Lazo

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29 Nuestro Futuro?

30 Human Rights Implications of Climate-Induced Threats to Access to Freshwater Martin Wagner Managing Attorney, International Program

31 Other Climate Impacts on Access to Water Saltwater Intrusion Drought Flooding

32 The Right to Water 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

33 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 drinkingwater.

34 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.

35 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.

36 What This Commission Can Do Formally recognize that climate change is a human rights issue, particularly in the context of water; Call upon all governments to make special efforts to promote equitable access to freshwater and to take steps now to prepare for increased constraints on freshwater access; and Call upon the governments most responsible for climate change: - to make the greatest possible efforts to mitigate climate change to minimize its impacts, through national and international action; and - to provide substantial assistance to the most-vulnerable, least-responsible governments as they address climateinduced threats to human rights.