Lesson 1: Social, Economic and Environmental Aspects of Climate Change Law and Policy



Lesson 1A: What is Climate Change?
When we speak of climate change on a global scale, we are referring to changes in the climate of the Earth as a whole. This phenomena was once called ‘global warming’, but ‘global climate change’ is the more accurate term. It refers to an overall shift in the global climate of the Earth. This shift is caused the ‘greenhouse effect.’ The green house effect is the phenomenon by which the sun’s energy, in the form of radiation, is trapped in our atmosphere by particles of water and gases (commonly called the greenhouse gases, as explained below) that collect and create a shield which blocks heat from escaping.



Lesson 1A: What is Climate Change?
This warming of the air and the Earth’s surface leads to changes in heat distribution which in turn affect heat related phenomenon such as weather, water distribution, precipitation, wind patterns, etc. When the energy budget (overall ‘heat’ retention) of the planet is modified, it has an impact on the overall climate. Climate change is a change in the “average weather” that a given region experiences. Scientists estimate that, at the present rate, greenhouse gases could lead to the Earth’s temperature increasing by 1°C to 3.5°C. This might not seem much, until we consider that the difference between an ice age and the climate that we currently enjoy is a mere 2°C to 3°C, on a global level.



Lesson 1B: Greenhouse Gases and Their Effects
The “Greenhouse Effect”
The greenhouse effect is an important phenomenon that affects the global climate of the planet. The temperature of Earth is determined by the balance between the flux of incoming radiation from the sun and the amount of outgoing infrared radiation reverted back into space. This balance is what regulates the temperature on the Earth. On entering the Earth’s atmosphere, solar radiation is either absorbed or scattered. Clouds, atmospheric gases and aerosols are responsible for the scattering and absorption of solar radiation. The amount of radiation absorbed is added to the planet’s heat budget. If more radiation is entering than leaving, slowly the global temperature increases and this leads to an enhanced greenhouse effect.