Climate change involves the change in the earth’s atmospheric temperature because of the emission of various pollutants and especially carbon dioxide (CO2).  It is claimed that climate change would cause significant environmental problems such as increased desertification, the flooding of small islands, and other unforeseeable environmental disasters.  Most scientists agree today that the earth’s temperature has been affected in a discernible matter by various pollutants but the extent of the change and whether it would bring global or regional detremental effects are severely contested.

Large emitters of carbon dioxide, such as the United States, have contested the severity of the climate change and have proposed to address it not only  by cutting emissions but also by regulating land use (such as decreasing the extent of deforestation in developing countries or planting new trees).  At the other extreme, the European Union has attempted to deal with the problem as a source problem by pursuing emission reductions.

The greenhouse effect, to which climate change is attributed, is a natural phenomenon.  It happens because naturally occurring greenhouse gases in the atmosphere absorb heat and emit it back to the earth.  As such the phenomenon is beneficial because, without it, the earth could be a cold planet deprived of life as we know it.  The problem is  that the increase  in the anthropogenic sources  of greenhouse gases has destabilized the natural balance between the emissions of  greenhouse gases and their removal by sinks (i.e. forests) creating fears of climate change.

Not all countries are expected to be impacted similarly by climate change.  Countries that are mostly threatened include those close to the sea –therefore vulnerable to the rise in sea levels– and countries prone to flooding. Thus small island states, the Netherlands and Bangladesh could be affected substantially.  The costs of abating climate change could be felt mostly in countries that produce greenhouse gases such as the United States,  Canada, China, India, Russia, Japan and Germany.  By 2015 it is expected that China will be the largest producer of CO2 followed by India.

The adoption of measures to address the climate change phenomenon was led by the Climate Change Convention that was adopted in 1992.  The convention is the outcome of its time as various countries, during the time of the adoption of the convention, contested that climate change is a phenomenon for which drastic action is needed.  The United States and oil producing states were against the adoption of measures that drastically curtailed greenhouse gases and proposed to deal with the problem not only by cutting emissions but also by using sinks (for instance, increasing forestation).  Some of the countries of the European Union were more eager to deal with greenhouse problem through emission reductions.  Eventually the instrument that was adopted was a framework convention that set the parameters of measures to be adopted but was not standard setting.

The Kyoto Protocol adopted in 1997 brings to the climate change regime the specific commitments that were missing in the climate change convention. The goal of the Kyoto Protocol is the reduction of emissions by at least 5 percent below the 1990 emission levels for the commitment period between 2008 and 2012.  The Kyoto Protocol adopted some innovative measures such as the Clean Development Mechanisms that gives the possibility for companies to get a certified reduction of their emissions by undertaking projects that reduce greenhouse emissions in developing countries.  The Kyoto Protocol entered into force after it was ratified by Russia in 2005. The United States has yet to ratify the protocol.  However, there has been an increasing rise of concern about climate change in many circles in the United States lately that, it is hoped, would lead to the endorsement of the protocol.  However, even the Kyoto Protocol may be too little too late and scientists are already discussing the means to adapt to an impending climate change.

The Paris Agreement adopted in 2015 encapsulates the commitment of states to deal with the threat of climate change by keeping a global temperature rise this century well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius. Additionally, the agreement aims to strengthen the ability of countries to deal with the impacts of climate change.