CORE - unit 2: Global Climate - vulnerability and resilience

The atmosphere

It consists of the mixture of solids, liquids and gases that are held to the earth by gravitational force. It consists of two elements – Weather and climate.

Weather

refers to the state of the atmosphere at a local level, usually on a short-term timescale from minutes to months. It includes temperature, precipitation, atmospheric pressure, wind speed and wind direction.

Climate

The average weather condition of a place taken over a given period of time, usually about 30 years. It is the long-term behaviour of the atmosphere in a specific place.

Global warming

The steady rise in global average temperature in recent decades, which experts believe is largely caused by human-produced greenhouse gas emissions

Feedback loop

Can be positive (adding to the rate of warming), or negative (reducing it)

Emissions

Any release of gases such as carbon dioxide which cause global warming, a major cause of climate change

Climate change

A pattern of change affecting global or regional climate, as measured by average temperature and rainfall, and how often extreme weather events like heat waves or heavy rains happen.

Troposphere

Lowest layer of the earth's atmosphere

stratosphere

Second layer of the earth's atmosphere

mesosphere

Third layer of the earth's atmosphere

Thermosphere

Fourth layer (uppermost) layer of the earth's atmosphere

Absorption

Mainly occurs in the ozone, carbon dioxide, particles of ice or dust.

Reflection

Takes place mainly by clouds and to a lesser extent, the surface of the earth. The ratio between incoming radiation and the amount of energy reflected, expressed as a percentage is known as albedo. Albedo varies with cloud type: 30- 40% in thin clouds, 50 – 70% in thick Stratos clouds, and 90% in cumulo-nimbus clouds.

Scattering

Occurs when solar radiation is diverted. It takes place in all directions and may reach the earth as diffuse radiation. Scattering or incoming solar radiation is diverted by particles of dust, molecules of gas, volcanoes and deserts.

Refraction

Occurs when energy moves from one type of space to another, such as from air into water. As the energy moves, it changes its speed and direction when reacting with the particles present in it. The shift in direction often causes the energy to bend and release the various light colours within it, similar to what happens as light passes through a crystal or prism.

Transmission

Occurs when both shortwave and longwave energy, instead of scattering, pass through the atmosphere.

Natural greenhouse effect

A natural process that warms the Earth's surface.

Horizontal heat transfers

The horizontal movement of air across the globe.

Vertical heat transfers

Vertical movement of heat into the atmosphere.

Milankovitch cycles

Variations in the tilt and/or orbit of the earth around the sun, referring to the three dominant cycles through which variations in the earth’s eccentricity (a measure of the shape’s deviation from being a circle), axial tilt and precession

Chlorofluorocarbons (CFCs)

Gases produced from aerosols, air conditioners, foam packaging and refrigerators

Enhanced greenhouse effect

Extra greenhouse gases in our atmosphere trap too much of the Sun's energy.

Biosphere

The part of the earth where life exists, up to a few kilometres into the atmosphere and deep into the earth’s crust or oceans. It is the part where living organisms exist.

Hydrosphere

The total amount of water on the earth, including underground waterz (groundwater, wells and aquifers), surface water (rivers, lakes and oceans, glaciers, icecaps) as well as water in the air (water vapour, clouds).

Atmosphere

A mixture of solids, liquids and gases that are held to the earth by gravitational force.

Cryosphere

The part of the the earth that is frozen – ice sheets, glaciers etc, most of which are in the Arctic and Antarctica

Resilience

The capacity of individuals, societies, organizations or environments to recover and resume ‘business as usual’ functions and operations following a hazard or other system shock.

Mitigation

Any action taken to reduce greenhouse gas (GHG) emissions, such as using less fossil fuels, thereby helping to slow down or ultimately stop climate change. Mitigation can occur at varying scales by different stakeholders, such as an individual turning off lights to reduce energy consumption.

Adaptation

Actions taken to protect people from the harmful effects of climate change without tackling the problem itself.

Cap and Trade

An environmental policy that places limits on the amount of natural resources that can be used, identifies the resource users, divides this amount into shares among the users and allows users to sell their shares if they are not willing to use it.

Carbon Emissions Trading (CET)

Giving firms and industries a limit to their emissions and fining firms who exceed this limit. The CET also allows for trade of carbon shares between firms and is done in the form of Cap and Trade. This is a scheme which allows for the gradual reduction of GHG emissions by industries and firms without much government intervention. CET is a form of environmental economy that gives firms the incentive to reduce their carbon emissions and shift to renewable energy use so that they can sell their remaining shares for profit.

Carbon Offsetting

This a scheme that encourages or requires businesses to sponsor activities or projects to reduce the amount of carbon in the atmosphere e.g. planting of trees as a way to compensate for their own emissions. In simple terms, it is a way of compensating for our emissions. Carbon offsetting can occur at varying scales. For example, individuals can pay the offset cost which is an extra cost placed on a good which is used to fund climate change mitigation projects by the business or firm (this is referred to as offsetting service provided by some commercial organizations).

Carbon capture and storage (CCS)

This technology aims at capturing released carbon dioxide from the burning of fossil fuels and burying it deep underground. Considering the fact that for years to come the burning of coal will continue to have a very significant part in the global energy budget as it is abundant and at a low cost.

Geo-engineering

The deliberate large-scale manipulation of the planetary environment in order to counteract anthropogenic climate change.

Sunlight Reflection Methods (SRM)

Technologies aimed to readjust the global energy balance by reducing incoming solar radiation. This would help in offsetting the global heating caused by rising greenhouse gas emissions. These technologies include: Placing mirrors in near-earth space orbit in order to reflect more sunlight back into space.