Impacts of global warming
Shifting climatic belts and biomes
Some 40 percent of ´major ecological biomes like forest, grassland, tundra – will have switched to a different such state. (NASA, 2011) : 30 percent change in vegetation cover.
Tipping point – climate change means ecosystem will change permanently.
Biodiversity
Increased temps and shifting climate zones then increase in danger for vulnerable species no longer able to adapt or migrate. Reduced adaptation time of different species, higher extinction risks, migrations.
Corals reefs – increase temps cause bleaching (whitening) and also acidification (absorb CO2 – acidic gas).
Greater rates of species extinction than already high rates! Domino positive feedback loops. Less carbon stores as forests decrease.
Desertification – spreading out of existing desert areas, grasslands dry, Drying of inland seas – aral, dead, etc…
Agriculture
Increase CO2 = increase plant growth. A raw material for photosynthesis, Better for farmers possibly but only if matched by similar increase moisture levels? (also needed for photosynthesis).
BUT: respiration rates also increase? – more CO2?
Farmers need predicable weather conditions – if changeable it will impact the crops they can grow and harvests.
Food production increases – increased population and more demand for meat diets.
Human health
Warmer conditions increase disease potential as cold winters kill off disease vectors (carriers) – increase malarial areas, dengue fever, yellow fever.
Warm/moist best for bacterial growth/disease. Dry/dusty – increase asthma, wet – increase fungal.
Extreme weather kills more people – floods, heatwaves, storms etc..
Melting ice caps and glaciers combined with thermal expansion of the seas
In the 2013 IPCC report, sea level is predicted to rise by 26. 98 cm by 2100, due to thethermal expansion (heating means expansion of water)of the oceans and the melting of polar ice-caps and ice sheets.
This increase in sea level could threaten many coastal ecosystems. Also at risk are mangrove forests and the low-lying freshwater wetlands, coral reefs, islands.
Coastal inundation- Low lying areas – Netherlands, pacific islands, coastal cities e.g. London.
Oceans absorb CO2 – carbon store but increases acidity. Arctic only minimal effect due to displacement in water, but will affect ocean currents such as warming north Atlantic drift, glaciers melt into sea,