Acid rain occurs when sulphur dioxide and nitrogen oxides are emitted into the atmosphere, undergo chemical transformations and are absorbed by water droplets in clouds. The droplets then fall to earth as rain, snow, or sleet.

The major causes of acid rain are the sulphur dioxide and nitrogen oxides produced when fossil fuels such as coal, oil and gas are burned and sulphur dioxide and nitrogen oxides are released into the atmosphere where they can be absorbed by the moisture and become weak sulphuric and nitric acids, sometimes with a pH of around 3.
Read more

It is estimated that there are presently some 30 million environmental refuges and a further 17 million other refugees and displaced persons from wars, persecution and other causes. The former have fled from resource scarcity, from deforestation and environmental degradation, climate change impacts, overpopulation, displacement by development projects, etc.

It has been suggested that the number of environmental refugees could rise to 150 million by 2050 as one of the results of climate change.
Read more

The water footprint of an individual, business or nation is defined as the total volume of freshwater that is used to produce the foods and services consumed by the individual, business or nation. A water footprint is generally expressed in terms of the volume of water use per year.

Since not all goods consumed in one particular country are produced in that country, the water footprint consists of two parts: use of domestic water resources and use of water outside the borders of the country. The water footprint includes both the water withdrawn from surface and groundwater and the use of soil water (in agricultural production).
Read more

Desertification has been defined as land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities.

Desertification directly affects over 250 million people. It threatens the lives of some 1.2 billion people in 110 countries who are among the world’s poorest and who depend on land for most of their needs.

A third of the Earth’s land surface, or over 4 billion hectares, is threatened by desertification.

Each year, desertification and drought cause an estimated US$ 42 billion in lost agricultural production worldwide. The annual cost of fighting land degradation is estimated at US$ 2.4 billion. Read more

Deserts cover about one fifth of the Earth’s surface.

With an area of 9,100,000 km2, the Sahara is the largest desert in the world and occupies approximately 10% of the African Continent.

The driest desert of the world is the Atacama Desert in Chile. For the period between 1964 and 2001, the average annual rainfall at the meteorological station in Quillagua was just 0.5 mm.
Read more