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Climate and Food Security Thank you to the Yaqui Valley and Indonesian Food Security Teams at Stanford

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Title: Climate and Food Security Thank you to the Yaqui Valley and Indonesian Food Security Teams at Stanford


1
Climate and Food Security Thank you to the
Yaqui Valley and Indonesian Food Security Teams
at Stanford
  1. Seasonal Climate Forecasts
  2. Natural cycles of drought
  3. Global Warming
  4. Impact of Agriculture on Climate

2
El Nino/Southern Oscillation (ENSO)A natural
mode of tropical atmosphere/ocean variability
  • Warm events return every 2-7 years, and tend to
    peak in NH winter

3
El Nino - Southern Oscillation (ENSO)
  • ENSO is a natural pattern of climate variability
    that is due to tight coupling between the
    atmosphere and ocean.
  • Small changes in the distribution of sea surface
    temperature are coordinated with changes in
    atmospheric circulation and rainfall patterns
  • The changed rainfall patterns in the tropics
    force atmospheric circulation changes that affect
    climate world-wide.

Precipitation Anomalies
Temperature Anomalies
4
DJF ENSO Impacts
http//www.cpc.ncep.noaa.gov/
5
ENSO is Predictable
  • ENSO is a true mode of the coupled
    atmosphere/ocean system (eg, patterns of
    oscillation in a guitar string)
  • The long period (3-4 years) of the ENSO mode
    allows for skillful seasonal climate forecasts
    (2-4 seasons in advance)
  • Presently, empirically based forecast models are
    at least as skillful as the numerical climate
    models.

6
Examples of applications of seasonal forecast
(based on ENSO forecasts)
  • Yaqui Valley, Mexico
  • Winter precipitation and reservoir inflow
    in-field precipitation health of grazing lands
  • Indonesia
  • Rice yields
  • Hurricane forecasts
  • frequency and intensity (Atlantic and Pacific)
  • Florida
  • Frost and citrus crops
  • Pacific Northwest
  • Snowpack and hydropower, flood events,
    recreation, stream flow, etc.

7
Products Forecasts of wintertime precipitation
in the Yaqui Valley Catchment (winter reservoir
inflow is correlated with wintertime
precipitation at r 0.87)
ENSO and NDJFMA precipitation
Winter Precipitation (mm)
Nino 3.4
  • For use with a forecast of ENSO
  • The prediction skill of the wintertime state of
    ENSO starting in October is gt 0.9

8
ENSO Impacts Java
Monsoon onset is delayed during ENSO warm
events. The delayed monsoon onset results in
reduced cumulative rainfall through wet season.
ENSO accounts for 61 of the variance in annual
rice production (1C Nino3.4 lt---gt 1 Gt rice
production)
9
Climate and Food Security Thank you to the
Yaqui Valley and Indonesian Food Security Teams
at Stanford
  1. Seasonal Climate Forecasts
  2. Natural cycles of drought
  3. Global Warming
  4. Impact of Agriculture on Climate

10
Decadal Variability in Sahel Precipitation
Change in Summer Precip
1970-90 Minus 1940-60
  • Precipitation in the Sahel is linked to Sea
    Surface Temperature changes (wet is associated
    with lower SST in the S. Atlantic and Indian
    Oceans)
  • Mainly due to natural climate variability some
    part due to 20th Century changes in CO2 and NH
    aerosols.
  • Future role of Global Warming unclear

Correlation of Sahel Summer Precipitation with SST
11
Historical Yaqui Reservoir Runoff, 1965-2004
Main Reservoir Yaqui System
1992
Fig. From Jose-Luis Minjares
2003
12
The recent drought in the Yaqui Valley how
extreme?
  • The reconstructed precipitation record extends
    from 1650 to 1985 AD.
  • The average return time for a drought similar to
    the most recent (winter) drought
  • six years at 63 of normal precipitation is about
    a century
  • Five years (1998-9 to 2002-3) at 50 of normal is
    unprecedent in 350 yrs.
  • For reference, the winter average precipitation
    for 1950-1960 was 79 of normal.

Note paleo records suggest numerous
megadroughts in past 1000 years in the US that
are presumably natural variability.
13
Climate and Food Security Thank you to the
Yaqui Valley and Indonesian Food Security Teams
at Stanford
  1. Seasonal Climate Forecasts
  2. Natural cycles of drought
  3. Global Warming
  4. Impact of Agriculture on Climate

14
Natural Climate Influence
Human Climate Influence
All Climate Influences
15
We Are We Headed?21st Century Climate Change
Projections
16
(No Transcript)
17
21st century temperature change
IPCC (www.ipcc.ch)
18
Projections of Future Climate
Temperature change, 2071-2100 minus 1961-1990
19
How will climate change due to increasing
greenhouse gases?
Many changes projected by the models are robust
and reliable. Examples of changes that are very
likely over the next 100 years include
  • the planet will warm, more so in middle and high
    latitudes than in the tropics
  • the hydrologic cycle will speed up
  • the area covered by snow and sea ice in winter
    will decrease
  • the sea level will rise
  • Increased flooding in some areas.

These changes will be much, much greater than the
changes seen over the past 150 years that have
been attributed to increased greenhouse gases and
aerosols.
20
Trend in Daily Temperature Range1950-1993
  • Night is warming faster than day.

21
Impacts of Climate Change on Agriculture
  • Increased growing season at high latitudes
  • Increased minimum temperature (crop growth and
    pest/pathogen effects)
  • Continental drying in midlatitudes (?)
  • Changes in timing of stream flow in mid and high
    latitudes (water availability, etc)
  • Changes in heat wave frequency and intensity
    change in frost days.
  • Changing patterns of drought.
  • CO2 effects on soil BGC, plant pathology ocean
    acidification, etc.

22
Projections of Future Climate
Precipitation change, 2071-2100 minus 1961-1990
23
How will climate change affect agriculture in the
tropics and subtropics?
It is highly likely that increasing CO2 will
cause large changes in the patterns and intensity
of precipitation throughout the tropics within
the next 50yrs, including
  • Changes in the annual cycle in precipitation
    throughout the tropics
  • The spatial and temporal structure of the
    monsoons will change in a significant way (eg,
    making places dry that are presently wet
    changing the duration of the monsoon)
  • Changes in ENSO
  • Changes in the teleconnection patterns associated
    with ENSO
  • Changing patterns, duration and intensity of
    drought (world-wide).

Unfortunately, the present generation of climate
models can not address these issues. But we are
making progress .
24
Thank you
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