Climate Change Food Security
Drought
Drought
The dryness and drought trend standard measure is the the Palmer Drought Severity Index. The 'Increasing Drought' map shows the global PDSI from 1900 to 2002. For most areas, drier (red and yellow) conditions have progressively increased over the century with a huge jump from 1880 to 1985. The bottom figure shows the trend over time of increasing drought, indicating that for much of the world, droughts are more common.(IPCC 2007).
The PDSI is being questioned to assess drought under climate change because it may overestimate area increase.
The PDSI is being questioned to assess drought under climate change because it may overestimate area increase.
Southern Europe
Climate change is projected to worsen conditions (high temperatures and drought) in a region already vulnerable to climate variability, and to reduce water availability, hydro power potential, summer tourism and, in general, crop productivity.
Africa
By 2020, between 75 and 250 million of people
are projected to be exposed to increased water
stress due to climate change.
By 2020, in some countries, yields from rain-fed
agriculture could be reduced by up to 50%.
Asia
Endemic morbidity and mortality due to diarrhea disease primarily associated with floods and droughts are expected to rise in East, South and South-East Asia due to projected changes in the hydrological cycle.
Australia New Zealand
By 2030, production from agriculture and forestry is projected to decline over much of southern and eastern Australia, and over parts of eastern New Zealand, due to increased drought and fire.
There is also high confidence that many semi-arid areas (e.g. the Mediterranean Basin, western United States, southern Africa and north-eastern Brazil) will suffer a decrease in water resources due to climate change. Drought-affected areas are projected to increase in extent, with the potential for adverse impacts on multiple sectors, e.g. agriculture, water supply, energy production and health. Regionally, large increases in irrigation water demand as a result of climate changes are projected.
Managing the Risks of Extreme Events and Disasters
to Advance Climate Change Adaptation (SREX) IPCC 2011.
Drought-affected areas are projected to increase in extent, with the potential for adverse impacts on
multiple sectors, e.g. agriculture, water supply, energy production and health.Synthesis Report
It is more likely than not that human influence has contributed to a global trend towards increases in area affected by drought since the 1970s.
Some regions of the world have experienced more intense and longer droughts, in particular in southern Europe and West Africa.
Droughts will intensify in the 21st century in some seasons and areas, due to reduced precipitation and/or increased evapotranspiration. This applies to regions including southern Europe and the Mediterranean region, central Europe, central North America, Central America and Mexico, northeast Brazil, and southern Africa
Climate change is projected to worsen conditions (high temperatures and drought) in a region already vulnerable to climate variability, and to reduce water availability, hydro power potential, summer tourism and, in general, crop productivity.
Africa
By 2020, between 75 and 250 million of people
are projected to be exposed to increased water
stress due to climate change.
By 2020, in some countries, yields from rain-fed
agriculture could be reduced by up to 50%.
Asia
Endemic morbidity and mortality due to diarrhea disease primarily associated with floods and droughts are expected to rise in East, South and South-East Asia due to projected changes in the hydrological cycle.
Australia New Zealand
By 2030, production from agriculture and forestry is projected to decline over much of southern and eastern Australia, and over parts of eastern New Zealand, due to increased drought and fire.
There is also high confidence that many semi-arid areas (e.g. the Mediterranean Basin, western United States, southern Africa and north-eastern Brazil) will suffer a decrease in water resources due to climate change. Drought-affected areas are projected to increase in extent, with the potential for adverse impacts on multiple sectors, e.g. agriculture, water supply, energy production and health. Regionally, large increases in irrigation water demand as a result of climate changes are projected.
Managing the Risks of Extreme Events and Disasters
to Advance Climate Change Adaptation (SREX) IPCC 2011.
Drought-affected areas are projected to increase in extent, with the potential for adverse impacts on
multiple sectors, e.g. agriculture, water supply, energy production and health.Synthesis Report
It is more likely than not that human influence has contributed to a global trend towards increases in area affected by drought since the 1970s.
Some regions of the world have experienced more intense and longer droughts, in particular in southern Europe and West Africa.
Droughts will intensify in the 21st century in some seasons and areas, due to reduced precipitation and/or increased evapotranspiration. This applies to regions including southern Europe and the Mediterranean region, central Europe, central North America, Central America and Mexico, northeast Brazil, and southern Africa
Climate Change: Drought may threaten much of globe within decades
UCAR site of research by A Dai The drought projections affect all the world's best food producing regions. At 1.8C severe drought affects all the world's food producing regions.
For more in depth see Dai 2011 Drought Under Global Warming Review
UCAR site of research by A Dai The drought projections affect all the world's best food producing regions. At 1.8C severe drought affects all the world's food producing regions.
For more in depth see Dai 2011 Drought Under Global Warming Review
Increasing drought affecting the world's best food producing regions in the Northern hemisphere threatens world grain reserves and world food security (Center for Climate and Security).
Why is drought suddenly increasing in the US and other Northern hemsiphere food producing?
Drought Is Increasing - more than doubled world wide according to A. Dai 2010.
However since 2012 the science on how much drought has increased in the past is in question.
The most recent paper is by A Dai 2012 and revised who upon review finds observations and models show world drought is increasing under global warming.
Currently (2012) top food producing regions in the US Russia and China are in a 3 year drought. The central US drought is forecast persist to spring 2013 at least.
The extreme US great grain belt drought is forecast to persist into spring of 2013
Drought, which is water shortage, can be defined in a number of ways. It will continue to increase as global warming continues and global temperatures increase.
Recently Northern hemisphere drought is increasing alarmingly, affecting all the world's best food producing regions. The rapid loss of Arctic cooling snow and ice albedo cooling is projected to increase N. hemisphere drought, so may now be a factor.
Why is drought suddenly increasing in the US and other Northern hemsiphere food producing?
Drought Is Increasing - more than doubled world wide according to A. Dai 2010.
However since 2012 the science on how much drought has increased in the past is in question.
The most recent paper is by A Dai 2012 and revised who upon review finds observations and models show world drought is increasing under global warming.
Currently (2012) top food producing regions in the US Russia and China are in a 3 year drought. The central US drought is forecast persist to spring 2013 at least.
The extreme US great grain belt drought is forecast to persist into spring of 2013
Drought, which is water shortage, can be defined in a number of ways. It will continue to increase as global warming continues and global temperatures increase.
Recently Northern hemisphere drought is increasing alarmingly, affecting all the world's best food producing regions. The rapid loss of Arctic cooling snow and ice albedo cooling is projected to increase N. hemisphere drought, so may now be a factor.
IPCC : Drought
IPCC 2007 Synthesis Report
It is more likely than not that human influence has contributed to a global trend towards increases in area affected by drought since the 1970s
There is now higher confidence in the projected increases in droughts, heat waves and floods, as well as their adverse impacts. Increases in drought, heat waves and floods are projected in many regions and would have mostly adverse impacts, including increased water stress and wild fire frequency, adverse effects on food production, adverse health effects,
IPCC 2007 Synthesis Report
It is more likely than not that human influence has contributed to a global trend towards increases in area affected by drought since the 1970s
There is now higher confidence in the projected increases in droughts, heat waves and floods, as well as their adverse impacts. Increases in drought, heat waves and floods are projected in many regions and would have mostly adverse impacts, including increased water stress and wild fire frequency, adverse effects on food production, adverse health effects,
N.B The climate crop models in the IPPC assessments to project effects of climate change on crop yields do not capture the impact of drought.
LIVESTOCK
The 2007 IPCC assessment found the impact of drought on livestock to be far more than
previous assessments. The impact on animal productivity due to increase variability
in weather patterns will likely be far greater than effects associated with the average
change in climatic conditions. Lack of prior conditioning to weather events most results
in catastrophic losses in confined cattle feedlots (Hahn et al., 2001), with economic
losses from reduced cattle performance exceeding those associated with cattle death
losses by several-fold (Mader, 2003).
A number of studies in Africa (see Table 5.3) and in Mongolia (Batima, 2003) show a strong relationship between drought and animal death. Projected increased temperature, combined with reduced precipitation in some regions (e.g., Southern Africa) would lead to increased loss of domestic herbivores during extreme events in drought-prone areas. With increased heat stress in the future, water requirements for livestock will increase significantly compared with current conditions, so that overgrazing near watering points is likely to expand (Batima et al., 2005).
The 2007 IPCC assessment found the impact of drought on livestock to be far more than
previous assessments. The impact on animal productivity due to increase variability
in weather patterns will likely be far greater than effects associated with the average
change in climatic conditions. Lack of prior conditioning to weather events most results
in catastrophic losses in confined cattle feedlots (Hahn et al., 2001), with economic
losses from reduced cattle performance exceeding those associated with cattle death
losses by several-fold (Mader, 2003).
A number of studies in Africa (see Table 5.3) and in Mongolia (Batima, 2003) show a strong relationship between drought and animal death. Projected increased temperature, combined with reduced precipitation in some regions (e.g., Southern Africa) would lead to increased loss of domestic herbivores during extreme events in drought-prone areas. With increased heat stress in the future, water requirements for livestock will increase significantly compared with current conditions, so that overgrazing near watering points is likely to expand (Batima et al., 2005).
IPCC Food chapterYields of grains and other crops could decrease substantially across the African continent because of increased frequency of drought, even if potential production increases due to increases in CO2 concentrations. Some crops (e.g., maize) could be discontinued in some areas. Livestock production would suffer due to deteriorated range land quality and changes in area from range land to unproductive shrub land and desert.
Drought is damaging of course the human population health by lack of water and increase in diseases. In past droughts - millions have died. This will greatly increase the effect of climate change induced food losses to human health and survival shown by the climate crop models .
Climate change through drought and flooding will increase soil erosion/land degradation, already a huge problem
being made worse by damaging farming and grazing practices eg China, Africa
Climate change through drought and flooding will increase soil erosion/land degradation, already a huge problem
being made worse by damaging farming and grazing practices eg China, Africa
2013 multi-year US & NH Drought
The world's most productive agricultural region is the US Great Plains called the world's breadbasket which stretches up to Canada. This region has a recent history and a far distant history of natural vulnerability to drought, and suffered a major drought in 2006. Climate change is projected to increase plains drought (USGS). The NOAA North American Drought Monitor covers this region. For current US drought check US Drought Portal.
The Future: drought will increase and spread more rapidly
Drought History page
Both (model) projections indicate Southern Europe, North Africa, Mexico, the Caribbean, and a large portion of the United States and Canada will likely to suffer dramatic increases in the incidence of drought.
Floods and Droughts in a Changing Climate – Now and the Future
April 29th, 2011 Paul A. Dirmeyer Center for Ocean-Land-Atmosphere Studies Maryland.
Floods and Droughts in a Changing Climate – Now and the Future
April 29th, 2011 Paul A. Dirmeyer Center for Ocean-Land-Atmosphere Studies Maryland.
The extent of increasing drought extent over the past 50 years according to the PDSI is questioned by new research, though the projection of drought increase with global warming is not in question.
There has been many severe NH extreme heat - drought events since 2000.
There has been many severe NH extreme heat - drought events since 2000.
There is a long history of episodic severe and long lasting affecting all the world's best food producing regions. Experts at a 2009 WMO workshop agreed that global warming will greatly increase this natural tendency, with increasing heat waves and more drought damage to crops.
The loss of Arctic cooling albedo especially the snow will increase NH heat waves, drought and prolong these extremes.
The loss of Arctic cooling albedo especially the snow will increase NH heat waves, drought and prolong these extremes.
