Chap 24A - Climate Change II

Define Food security

Food security (Def.): When all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food that meets their dietary needs for an active and healthy life

State impact of climate change on crops

Yield

Irrigation and water availability

Planting and Harvesting

Decreased Arability (quality of land for cultivation)

Increase in Pests and Diseases

Nutritional Quality of Crops

Describe impact of climate change on crop yield

1. CO2 fertilisation effect: Stimulate photosynthesis and plant growth initially 

• Plants have fewer stomata: Each individual stoma is able to bring in more CO2 AND fewer stomata helps plants reduce water loss via transpiration due to higher global temperatures 

2. Increased temperatures 

• Increase respiration rates

• Reduce photosynthetic efficiency

• Impair enzyme function

  • Eg. Bees overheat -> cellular enzymes denatured -> declining bumble bee populations -> less pollination -> lower yield 

• Disrupt reproductive processes like flowering and seed formation

Describe impact of climate change on crop irrigation and water availability

1. Reduced rainfall

• Increased irrigation costs

• Competition over water resources

• Potential conflicts over water access

Describe impact of climate change on crop Planting and Harvesting

1. Heavy precipitation and flooding 

• Waterlogging -> deprives plant roots of O2 -> reduce nutrient uptake and growth

• Soil erosion

• Destruction of vegetable plots

• Reduced crop yield

Describe impact of climate change on crop Decreased Arability (quality of land for cultivation)

• Climate change may shift optimal agricultural zones toward higher latitudes where temperatures are more suitable for crop growth

• BUT soils in new regions lack appropriate nutrients or agricultural infrastructure -> limit productivity

Describe impact of climate change on crop Increase in Pests and Diseases

• Warmer temperatures and changing humidity conditions allow many insect pests and plant pathogens to survive more easily and reproduce more rapidly

• Increased pest pressure -> farmers use more pesticides -> increases the risk of pesticide residues entering the food chain -> evolution of pesticide resistance

Describe impact of climate change on crop Nutritional Quality of Crops

Increase CO2 concentrations reduce the concentration of protein and essential minerals in crops like wheat -> reduces the nutritional quality of food

State impact of climate change on livestock

Heat Stress on Animals

Pastures and Feed Supply

Increase in Pests and Diseases

Describe impact of climate change on livestock heat stress

Heat Stress on Animals

Animals experiencing heat stress may: Reduce grazing time (due to seeking shade) Decrease feed intake Increase panting and sweating Lose body weight More vulnerable to disease Eg. In dairy cattle: heat stress reduces milk production, lowers milk fat and protein content and decreases reproductive efficiency

Describe impact of climate change on livestock Pastures and Feed Supply

Pastures and Feed Supply

Drought conditions: Reduce pasture growth and availability of high-quality forage for grazing animals Rising atmospheric CO2: Reduce the nutritional value of feed plant -> animals consume more food to obtain adequate nutrition

Describe impact of climate change on fisheries

Changes in Species Distribution and Life Cycles	Rising water temperatures alter spawning times and drive fish species toward cooler regions at higher latitudes -> greater competition with existing species -> affecting ecosystem balance and availability of fish for consumption
Ocean Acidification and Shellfish	Acidic conditions reduce CaCO3 availability for shell formation in shellfish -> shells weaker and growth is impaired -> reduce shellfish survival and affect seafood supply