This animation of the carbon cycle shows the exchanges of carbon dioxide between the planet’s 4 natural reservoirs ( atmosphere, biosphere, lithosphere, hydrosphere). Carbon dioxide is a greenhouse gas. The natural carbon cycle is balanced.
Human activities (industrialization, deforestation, combustion of fossil fuels) alter these exchanges and are at the origin of an excess of waste CO2 in our atmosphere. Only 50% of these wastes are absorbed by natural carbon wells (biomass and ocean).

The water we drink has been collected in some catchments like underground aquifers and surface waters. Unless the water collected is already of very high quality, it undergoes various treatment processes that remove any contaminants that could be harmful to human health.
This animation follows step by step the different stages of the process which combines physical, chemical and biological actions.

This animation illustrates the main stages of the wastewater treatment process.
The treatment of wastewater is essential before the water is returned to nature. With more than 15,000  treatment plants, France collects and treats 70% of its wastewater.

The treatment cycle combines mechanical procedures (screening, clarification…) and physiochemical ones (biological treatment).  The net output of unpolluted water from these plants is estimated to be, on average, 75%.

A water tower is used to store drinking water, which is pumped up to the holding tank at the top of the structure. The tank must be higher than the end-users so that enough pressure is exerted to allow the water to reach them via the distribution network, thereby obeying the laws of communicating vessels.

This animation shows how water is distributed by gravity throughout a community. You can change the height of the water tower by clicking on and dragging its tank.

Photovoltaic panels consist of many cells made of semiconductor material.

They convert light energy into electrical energy. Batteries are used to store this energy during the day and to release it back at night.

On the Earth’s surface, water is heated by the sun and evaporates into water vapour. As it rises into the atmosphere, the vapour condenses to form clouds which produce precipitation (rain, snow…). Some of this precipitation evaporates, while some seeps into the ground to supply the ground water table or to add to the volume of glaciers. The rest is carried back to the sea by steams and rivers.