Unit 7.2 Causes and impact Flashcards
Climate change
a long-term change in the average weather patterns that have come to define Earth’s local, regional and global climates
Is climate change something new?
has been a normal feature of the Earth’s history, but human activity has contributed to recent changes. The ice ages that have occurred throughout geological time are clear evidence of such climate change.
Causes of natural changes to global climate
- changes in solar radiation
- slow variations in the Earth’s orbit
- slow changes in the angle of the Earth’s axis
- changes in the albedo of the Earth and atmosphere
- changes in the long wave radiation returned to space
- carbon dioxide levels from geological times to the present
Mantra for climate change. Why are we concerned
- Increase in average global temperature
- Increased frequency and intensity of extreme weather events
- Rise in sea level
Impacts of climate change
may vary from one location to another and may be perceived as either adverse or beneficial
Climate
describes how the atmosphere behaves
over relatively long periods (minimum 30
years)
Factors that affect climate and weather
The circulation systems in the atmosphere and the
oceans have a major impact on weather and climate.
Weather
describes the conditions in the atmosphere over a short period (today, tomorrow, next week).
Global atmospheric circulation
The basic cause of air motion is the unequal heating of the Earth’s surface.
Ocean currents
Warm ocean currents move water away from the equator, whereas cold ocean currents move water away from cold regions towards the equator.
IMPACTS OF CLIMATE CHANGE ON
ECOSYSTEMS
- Alter climate biomes and species found
- Animals may move toward cooler areas and polar regions face extinction risks as they can’t move further
- Plants cannot move, particularly vulnerable to climate shifts.
- Increased droughts more frequent and intense wildfires, destroying habitats and species.
- Sea temperature rise can lead to coral bleaching and death, impacting entire marine food webs and ecosystems.
IMPACTS OF CLIMATE CHANGE ON FOOD
PRODUCTION
- Higher temperatures may boost photosynthesis rates.
- Already seen in Europe, potentially leading to longer crop production periods.
- Outcomes depend on soil health; not all regions may benefit equally.
- Even slight ocean warming can be fatal for plankton, disrupting marine ecosystems.
- Extreme heat and drought can lead to increased livestock mortality.
IMPACTS OF CLIMATE CHANGE ON ARCTIC
AND ALPINE REGIONS
- Melting ice may create navigable passages, easing travel and trade.
- Potential to tap into previously inaccessible undersea minerals and fossil fuels.
- Can cause flooding and landslides due to unstable land and water overflow.
- Glacial melt is crucial for freshwater supply; its loss could lead to droughts.
IMPACTS OF CLIMATE CHANGE ON HUMAN HEALTH
- Higher latitudes may see a decrease in mortality due to less extreme cold.
- Warmer temperatures could reduce the need for heating, saving on household expenses.
- A decrease in snowstorms and ice may lead to fewer road accidents.
- Increased frequency of heatwaves could result in higher heat-related fatalities.
- Warmer winters may allow insects that carry diseases to survive in new areas.
- Illnesses like malaria, yellow fever, and dengue could affect more regions.
- More humidity could lead to a rise in fungal infections.
- Dryer conditions could exacerbate respiratory problems due to increased dust.
IMPACTS OF CLIMATE CHANGE ON HUMAN MIGRATION
- If people cannot grow food or find water, they will move to regions where they can. The IPCC estimates 150 million environmental refugees from climate change by 2050
IMPACTS OF CLIMATE CHANGE ON NATIONAL ECONOMIES
- If rivers do not freeze, hydroelectric power generation could be possible at higher latitudes
- Some economies will benefit if it becomes easier to exploit mineral reserves that would have been
frozen in the permafrost or under ice sheets - Agricultural production may rise in higher latitudes but fall in the tropics.
- Water wars would be more common if water supplies decrease or drought occurs
- Africa will probably lose food production and rainfall
- Global migration (environmental refugees) will have implications for nation-states, services and
economic and security policies - Up to 40 nations will be directly affected by sea level rising. Low low-lying states like Bangladesh would lose land area. Tuvalu would disappear completely
IMPACTS OF CLIMATE CHANGE ON WEATHER PATTERNS
- More heat means more energy in the climate and so the weather will be more violent and sporadic
with bigger storms and more severe droughts. - Global precipitation may increase by 15%, which will lead to more soil erosion
- Hurricanes will be stronger and more intense.
The climate change debate
- Recognized as a critical issue, but there is opposition
The relationship between the atmosphere, land, and oceans is intricate and challenging to model accurately
- While our knowledge is advancing, our understanding of climate feedback mechanisms is incomplete.
- Effects of changes not apparent due to the prolonged nature of climate processes.
- Global climate models contain uncertainties, leading to varied confidence in predictions.
- Scientists are unequivocally saying there is a relationship such as the IPPC. no doubt
IPCC Role: The Intergovernmental Panel on Climate Change assesses a range of climate change data and projections.
Feedback mechanisms associated with an increase in mean global temperature
Positive feedback on global warming
Negative feedback on global warming
