Climate change is a very different matter.
The greenhouse effect is a natural atmospheric process caused by the presence of certain gases in the atmospheric process caused by the presence of certain gases in the atmosphere that prevent the infrared radiation emitted from escaping from the earth's surface to space. As a result, the temperature of the atmosphere increases, until a new equilibrium between in going solar radiation and out going infrared radiation is reached. The process is analogous to the way in which a greenhouse increases the temperature inside. The gases that absorb out going infrared radiation are called green house gases (GHG's). Some GHG's are that exists naturally: carbon dioxide (Co2) and small quantities of Methane (CH4). Thus the greenhouse effect has always been with us. In its absence, the earth's mean temperature would be 30C lower than it is, which would mean the end of life on the planet, an ice covered places. The progressive gradual rise of the earth's average surface temperature, thought to be caused in part by increased concentrations of GHG's in the atmosphere, is called global warming, which is commonly described as climate change, although global warming is only one of the changes that affect the global climate.
Our main concern is that since the industrial revolution there has been a considerable increase in emissions of GHG's resulting in considerable increase in their concentrations in earth's atmosphere. The natural balance of the greenhouse effect is currently lost. One to this serious nature of climate change a widely recognized organization IPCC was setup in 1988. The scientific evidence that human activities are changing the climate of our planet has been studied by a working group of the intergovernmental panel on climate change, or IPCC, an international scientific body intended to provide policymakers with an authoritative view of climate change and its causes and affect. The IPCC includes three working groups: (i) Working group 1 (WG1) assesses the scientific aspects of the climate system and climate change (ii) working group 2 (WG2) assesses the vulnerability of Socio-economic and natural system of climate changes and options for adopting it; (iii) working groups 3 (WG3) assesses the options for limiting GHG emissions and otherwise mitigating climate change. Every few years, each working group publishes an assessment reports. The fourth of these reports (called AR4) was published this year. Working group 1 has already its part of AR4 (IPCC, 2007 a). Some of their findings are:
Global atmospheric concentrations of carbon dioxide, methane and nitrous oxide have increased markedly as a result of human activities since 1750 and non for exceed pre-industrial value. The global increases in carbon dioxide concentration are primarily to fossil fuel use and land-use change, while those of Methane and Nitrous oxide are primarily due to agriculture. (ii) Warming of climate system is unequivocal, as is no evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global mean sea level. (iii) At continental, regional and