Changes in precipitation and water Changes in precipitation and - - PowerPoint PPT Presentation

Changes in precipitation and water in the Americas with climate change Kevin E Trenberth NCAR

Thanks to Ray Bradley

Changes in precipitation and water in the Americas with climate change Kevin E Trenberth NCAR

Thanks to Ray Bradley

Global temperature and carbon dioxide: anomalies through 2010 Global temperature and carbon dioxide: anomalies through 2010

Base period 1900-99; data from NOAA

How should precipitation change as climate changes? 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

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

sequence

• The phase

phase: snow or rain The intensity and phase affect how much runs off versus how much soaks into the soils. The intensity and phase affect how much runs off versus how much soaks into the soils.

Most precipitation comes from moisture convergence by weather systems Most precipitation comes from moisture convergence by weather systems

Rain comes from moisture convergence by low level winds:

More moisture means heavier rains

Smoothed annual anomalies for precipitation (%) over land from 1900 to 2005; other regions are dominated by variability.

Land precipitation is changing significantly over broad areas Land precipitation is changing significantly over broad areas Increases Decreases

IPCC

Precipitation

Observed trends (%) per decade for 1951–2003 contribution to total annual from

very wet days

> 95th %ile.

Alexander et al 2006 IPCC AR4

Precipitation

Observed trends (%) per decade for 1951–2003 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. Heavy precipitation days are increasing even in places where precipitation is decreasing.

The most important spatial pattern (top) of the monthly Palmer Drought Severity Index (PDSI) for 1900 to 2002. The time series (below) accounts for most of the trend in PDSI. The most important spatial pattern (top) of the monthly Palmer Drought Severity Index (PDSI) for 1900 to 2002. The time series (below) accounts for most of the trend in PDSI. Drought is increasing most places Drought is increasing most places Mainly decrease in rain

• ver land in tropics and

subtropics, but enhanced by increased atmospheric demand with warming

Dai et al 2004 IPCC 2007

Source: Francou & Vincent, 2007

Glaciers are retreating around the world

Change in length and area of 10 tropical Andean glaciers

Ecuador Peru Bolivia

Source: Bradley et al., 2006

Limited data Limited data

Glaciers will continue to melt!

Projected change in temperature* (1990-99) to (2090-99) along the American Cordillera, from Alaska to Chile

South North

*Mean of 8 GCM simulations from IPCC 4th Assessment using scenario A2

Mountain peaks

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

Spring 1934 (Kern, 1937) Spring 1934 (Kern, 1937) Photo: Carsten Braun

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

Spring 1934 (Kern, 1937) Spring 1934 (Kern, 1937) Photo: Carsten Braun

Ice margin was ~200m lower in 1952, even lower in 1934 (inset)

4680m 4942m 1952: 4500m 1934: 4300?m

Nevado Nevado de Santa Isabel, Colombia de Santa Isabel, Colombia

Tolima: 5215m Ruiz: 5320m Santa Isabel: 4965m

Sources: J. Ramírez Cadena & GRID‐ARENAL, UNEP

44% mass loss

Photo: Dave Semler and Marsha Steffen

Cotopaxi, Ecuador (5897m)

Mean loss in glacier area, 1976‐1997: 30%

Source: Jordan et al., 2005

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

2009

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

Model predictions “Rich get richer, poor get poorer” Model predictions “Rich get richer, poor get poorer”

Conclusions: The need for environmental justice 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

From Istockphoto.com

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?

Comunidad Khapi y el Illimani Comunidad Khapi y el Illimani

Alivio Alivio Aruquipa Aruquipa Lazo Lazo

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

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

1920 2008

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.”

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 climate- induced threats to human rights.

Photo Credits:

• Bolivia images courtesy of Agua Sustentable
• Saltwater Intrusion: Mecocrus, Flickr/Creative Commons
• Drought: America Perales, Flickr/Creative Commons
• Flood: NOAA Photo Library, Flickr/Creative Commons