Geography, Dynamic planet

Why do tectonic plates move?

• Earths interior is made up of a layered structure
• Core generates heat, causing a convection current, moving the plates and generating the Earths' magnetic field

Different types of plate boundaries-

• Conservative
• Constructive
• Destructive

All the above can cause volcanoes and earthquakes

How and why has climates changed in the past?

Changed in the past due to natural causes:

• Ice ages- Quaternary period and UK climate since roman times
• Asteroid collisions
• Orbital changes
• Volcanic activity
• Changes in solar output

Natural climate change has affected people and the environment

Climate change in the UK is happening due to human activity

Human activity is releasing methane and carbon dioxide into the atmosphere- adding to the greenhouse effect

Future climates are uncertain but are likely to present us with major economic and environmental clallanges to the Uk, and especially to developig countries

The distribution of global biomes reflect climate as well as localised factors

Eco-system= A unit made up of living things and their non-living environment, e.g. a pond, a forest, a desert, etc

Biome= A very large ecosystem, e.g.a rainforest or hot deserts

Distribution due to temperature and precipitation-

• Precipitation happens at low-pressure belts. Happens along the equator and at mid latitude points, such as the UK. This forms forests
• In polar and dessert areas, High-pressure belts occur- causing dry conditions
• Temperature decreases as you move further from the equator. As lattitude decreases, so does temperature
• In polar areas, sun rays are less concentrated do there is a lack of heat, and vegetation doesn't grow well due to light limitations

Local factors

• Altitude: every 100m, the temperature drops by 1 degree celcius
• Soil: how nutrient-rich the soil is

Biosphere acts as a 'life-support system' and produces a wide range of goods

The biosphere:

• regulates the composition of the atmosphere,
• maintains soil health
• Influences the hydraulic system

Provides humans with:

• Raw materials
• Medicines
• Food

The biosphere is being degraded by human actions:

• Destruction of rainforests
• Deforestation for timber
• Mining
• Conservation of agricultural land

Impacts of climate change on the rainforests:

• Transpiration is reduced and evapouration is increased- leading to a drier climate
• Deforestation leads to global warming because trees use up carbon dioxide

The hydrological cycle regulates water supply and links the atmosphere, lithosphere and biosphere

How the hydrological system works:

It's a system of interlinked stores and transfers, including the process of evapouration, condensation, precipitation and run-off

Changes to the hydrolaugical systems affect both humans and the eco-system

• Rainfall reliability
• Groundwater levels
• Dry, arid area's

There are many threats to the hydrological system such as:

• human activity: Sewage disposal
• human activity: Industrial pollution
• human activity: Intensive agriculture

There are a range of strategies, at a variety of scales, designed to manage water resources more sustainably using different levels of technology.

Geological structure and land type have a major influence on costal development and landforms.

Marine processes and sub- aerial processes, mass movement and climate change are also greatly important.

Sub aerial processes shape land by weathering and mass movement

Mass movement occur on slopes under different conditions

• Concequences of climate change on marine ersoion and deposition include an increased:
• frequency of storms
• rising sea levels

Physical processes lead to costal change and retreat, which threatens people and property and generates condlict views

There are a range of costal management options from the traditional hard engineering and more holistic approaches

'Do nothing'- Intergrated Costal Zone Management (ICZM)

Extreme climates: Hot arid and cold polar- both fragile environments

• Hot arid flora and fauna:
• Moss: survives by growing close to the ground- can't get blown over by strong winds

People have adapted to living in these conditions in many ways

Extreme environments are under threat in many ways, such as climate change

• Threats to people in natural systems:
•  
• Out- migration- becase of its limited economic oppertunities
• Cultural dilution through tourism
• Pollution through land exploitation
• Land degradation through poor land management

• Climate change can threaten natural systems through:
• Permafrost
• Loss of sea ice
• Desertification
• Species migration