The average temperature of the planet has risen by 0.6°C in the 20th century, 0.9°C in France. In the current century, it should increase by at least 1.4°C, up to 5.8°C if nothing is done. This is an unprecedented evolution in the last tens of thousand years. It has been established with certainty that this phenomenon is due to the increase in greenhouse gas emissions associated with human activities, in particular carbon dioxide (CO2).
2What is the greenhouse effect?2
The greenhouse effect is a natural phenomenon. The solar energy reaching the ground warms up the Earth and transforms into infrared rays. Like the windows of a greenhouse – hence the name of this process – gases present in the atmosphere trap part of these rays which tend to warm up the atmosphere. Thus, without the greenhouse effect, the average temperature on Earth would be -18 °C and not much water would be in liquid form. Therefore this effect has a beneficial influence as it provides an average temperature of 15°C, and consequently life on earth.
2Relationship between the greenhouse effect and global warming:2
Man has discharged gases into the atmosphere since the beginning of the industrial era (carbon dioxide, methane, nitrogen oxides etc.), artificially increasing the greenhouse effect. While this contribution to the natural greenhouse effect is hardly significant (approximately +1%), it is enhanced by water vapour and consequently contributes to the increase in the average temperature of our planet by approximately 0.5°C in the second half of the twentieth century.
2Consequences of the greenhouse effect:2
The last few years have given an indication of the risks inherent in climate change at European level: even though it is generally impossible to blame climate change for any given extreme climatic event (storm, flooding, heat wave etc.), the facts observed are a fair reflection of the results of the Intergovernmental Panel on Climate Change (IPCC). Certain effects of climate change are already visible in France: average annual temperature up by 0.9°C over one century and melting of glaciers.
In the very long term, significant disturbances may also occur in sea currents and polar ice caps, with consequences on the spread of global warming according to the regions of the world, notably less significant in Northern Europe. 2Greenhouse gas and industry:2 Man-led industrial activities generate increasing amounts of “greenhouse gases”. While these gases help produce the greenhouse effect, their excessive quantity raises global temperature to artificially high, climate-altering levels.
Thus, the Kyoto protocol signed on 11 December 1997 sets out quantified objectives for the reduction in greenhouse gas emissions to control global warming. Since it came into force on 16 February 2005, it has imposed quantified objectives in terms of reduction or limitation in greenhouse gas emissions upon thirty industrialised countries.
Under this protocol, industrialised countries will have to reduce their combined emissions of the six main greenhouse gases, expressed in CO2 equivalent as per their global warming potential (GWP) below 1990 level, during the 2008-2012 period. The European Union, for example, will have to reduce its combined emissions by 8% while France will have to stabilise its emissions.
The Kyoto Protocol imposes a limit on the total amount of greenhouse gas emissions of each industrialised country: these countries have individual emissions objectives that need to be complied with.
On 1st January 2005, the European Union has set up a greenhouse gas emissions trading system, enabling a certain number of companies of the 27 Member States to purchase and sell the right to emit CO2, in application of the European Parliament and Council directive 2003/87/CE of 13 October 2003.
For France, a national quota allocation plan for the 2008-2012 period was approved by decree no. 2007-979 of 15 May 2007 and the order of 31 May 2007 set the list of operators with greenhouse gas quotas and the amount of these quotas. The Inspectorate of classified installations approves the carbon dioxide monitoring plan for concerned installations and verifies the emissions disclosed by the operators.
It should also be noted that for several years France has undertaken a series of actions aiming at limiting its emissions of greenhouse gases. Thus, France has adopted a climate plan to face up to the challenge of climate change by 2010, by complying with, if not exceeding the objective of the Kyoto protocol. The programme law defining the orientations of the energy policy (law no. 2005-781 of 13 July 2005) aims at reducing greenhouse gas emissions by 3% each year in order to cut French emissions by four by 2050. More recently, ambitious measures were decided in November 2007 within the framework of the Grenelle of the Environment: raise the percentage of renewable energies to 20% of the energy consumption by 2020, significantly reduce the emissions from the transport sector, and voluntarily accelerate progress in the building sector.