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What are the different anthropogenic causes for Climate Change?
Burning of Fossil Fuels
Changing Land Use.
Explain how does burning of fossil fuels lead to enhanced greenhouse effect with examples.
Fossil Fuels contain high carbon content. The burning of fossil fuels such as coal produces large amounts of carbon dioxide and other greenhouse gases into the atmosphere, trapping heat and contributes to the greenhouse effect.
For example, the usage of fossil fuels increased during the Industrial Revolution in 1880s contributing to more than 35 billion tonnes of carbon dioxide emissions per year.
State what are the different factors of changing land use.
Agriculture.
Industries.
Urbanization.
Deforestation.
Explain how Changing Land Use (Deforestation) contributes to the enhanced greenhouse effect.
Changing land use for agriculture, industries and urbanization require space to be made for it, hence deforestation free up space and also contributes to the enhanced greenhouse effect.
By cutting down trees, it results in higher amounts of carbon dioxide in the atmosphere due to less trees absorbing carbon dioxide for photosynthesis.
Trees are also carbon stores, and when they are cut down, stored carbon in these trees are released back into the atmosphere as carbon dioxide.
Clearing of trees also exposes the soil beneath to sunlight. increasing soil temperature and carbon oxidation rate.
For example, tropical deforestation contributes around 20% to global carbon dioxide and greenhouse gas emissions.
Explain how Changing Land Use (Agriculture) contributes to the enhanced greenhouse effect.
As our population grow, more trees and plants are cleared to make space for agriculture and cattle rearing to meet the growing demand for food.
They contribute at least 30% of global greenhouse gas emissions due to the burning of fossil fuels to generate energy for machinery, Nitrogen in chemical fertilizers being converted into nitrous oxide as well as Livestock rearing and natural decomposition processes releasing methane into the atmosphere.
For example, in Thailand’s Rice paddy fields, decomposition is rapid due to the high moisture content in the soil which contributes up to 20% of total methane emissions.
Explain how Changing Land Use (Industries) contributes to the enhanced greenhouse effect.
Industries burn fossil fuels to generate energy for machinery and other factory processes to process and produce materials.
For example, it is estimated that industries contribute around 43% of greenhouse gases annually.
Explain how changing Land Use (Urbanization) contributes to the enhanced greenhouse effect.
In cities, fossil fuels are burnt to generate energy to power high concentration of vehicles on the road as well as household activities such as doing the laundry, heating and cooling of houses.
Cities consume about 78% of the world’s energy and contribute significantly to the emission of greenhouse gases.
What are the different impacts of Climate Change on Natural Systems?
Increasing Atmospheric Temperature
Changes Down Of Ocean Circulations
Changes in Precipitation on Land.
P- Principal | Precipitation on Land |
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O- Of | Ocean Circulation |
A- Accounting | increase in Atmospheric temperatures |
Explain how Climate Change affects Increase in Atmospheric Temperatures.
Most of the heat from the sun is trapped by greenhouse gases and absorbed by the oceans. Average temperatures of oceans have been increasing, and have warmed slightly over 1 degree cel.
Some parts of these heating are uneven throughout the world. Some parts of the ocean will be warmer than others.
Explain How Climate Change affects Changes in Ocean Circulation
(Explain Process First) Warm surface water moves from the equator to the poles due to the winds. The water cools, becomes more dense and sinks to the bottom of the ocean floor and spreads along it and form cool subsurface flows. the cold water then eventually gains heat and rises back to the surface of the ocean.
However, due to climate change, it excessively heats up the surface water, making water less dense and not able to sink as fast as before, hence slowing down ocean circulation.
→ This eventually links to how it affects marine food webs due to phytoplankton and the species that feed on it.
Explain How Climate Change affects Changes in Precipitation on Land.
In drier areas, results in water evaporating into more water vapor into the atmosphere and dries out the soil and vegetation moisture. The air is able to hold more water vapor due to the high temperatures reducing rainfall. Especially in drier areas, the climate can get even drier, which can result in droughts at areas near the subtropics.
However in the wetter areas, more water is evaporating into more water vapor. More water vapor is able to be retained in warmer air. Hence, precipitation and excessive rainfall increases, causing floods to occur.
→ This is later on linked to the effects of floods on flora and fauna.
How does Climate Change affect Aquatic Ecosystems?
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How does Climate Change affect Ocean Acidification?
Due to the presence of phytoplankton in the water, oceans are natural carbon sinks and absorb more carbon dioxide from the atmosphere. The carbon dioxide dissolves into the water, forming carbonic acid which erodes calcium carbonate which is used to make the shells of crustaceans like oysters as well as corals. Corals then erode faster than they can grow.
For example, Ocean Acidity has increased since the Industrial Revolution by 25% and Average Coral Cover in the Great Barrier Reef has decreased about 30% of what it used to be in the 1960s.
How does Climate Change affect Coral Bleaching? (with Examples)
Climate Change causes ocean temperatures to increase, causing algae to leave the coral, causing coral to lose its major food source and cause them to turn white and susceptible to diseases.
Other species who then rely on corals for food or habitat will also be affected due to coral bleaching because corals are home to millions of aquatic species like fish.
The Great Barrier Reef in Australia was severely affected in 2016 due to rising sea temperatures, and 2/3 of their corals in the northern region died. Species diversity has also decreased significantly.
How does Climate Change increase Disruption of Aquatic Food Webs? (2 Components)
Slowing down of ocean circulation delays the transport of nutrients from subsurface waters to deep waters.
For example, Phytoplankton in the water are forced to rise and remain in the surface waters, separating them from the deep waters and are unable to get the nutrients they need and end up dying.
When Phytoplankton die, their population decreases and other species that depend on them for food will also be affected along with the whole food chain.
( Phytoplankton levels dropped by 10% during the industrial revolution period.)
Increase in atmospheric temperatures can cause changes in geographical distribution and composition of aquatic ecosystems.
Due to the warming oceans, many aquatic animals are migrating pole wards to cooler waters. This causes a drop in biodiversity in equatorial waters and increased biodiversity in poleward regions
For example, rabbitfish and parrotfish have been migrating poleward towards Japan and Australia in search of cooler waters
(composition) The mix of prey and predators in the water also changes which disrupts aquatic food webs.
For example, rabbitfish and parrotfish migrated poleward to Japan and Australia for cooler waters. These fish then consume kelp and flourish, however it causes a huge decrease in kelp population, affecting other animals that feed on kelp or rely on it for protection. In Japan, lobsters have also declined due to the lack of kelp.
Some aquatic plants are also unable to migrate to cooler waters and are unable to adapt, hence they die