Greenhouse effect, Climate Change, and Kyoto Protocol

	Greenhouse effect Climate Change Kyoto Protocol
Links Home Sustainability Nuclear pollution Greenhouse effect Ozone depletion Toxic chemicals Parco dei Colli	Some gases in the atmosphere produce the "greenhouse effect", trapping the heat of Earth without allowing it to escape in the outer space. The greenhouse effect is normally natural and beneficial : without it Earth would be at least 15 ° C colder; it is becoming more and more important due to the increasing concentration of these gases ("greenhouse gases") in the atmosphere due to human activity. The main greenhouse gases are : carbon dioxide (CO₂) , methane, nitrous oxide (N₂O), chlorofluorocarbons (CFCs); also water vapour (H₂O) is producing the greenhouse effect. Carbon dioxide The concentration of the most important greenhouse gas, carbon dioxide, has increased in the atmosphere from 290 ppmv (parts per millions by volume) in 1880 to about 380 ppmv in 2006, and is going to increase in the next future, because carbon dioxide, with water, is the final product of the combustion of fossil fuels (oil and derivatives, methane and hydrocarbons, coal), and of living and dead vegetation (biomass burning). The fossil fuels can be considered reservoirs of carbon, made ages ago; their combustion lets carbon return (as dioxide) into the atmosphere, increasing the greenhouse effect. Carbon dioxide is easily soluble in water : the oceans contain enormous amounts of it, but the temperature increase ( due to the greenhouse effect) reduces its water solubility, releasing new gas into the atmosphere, and accelerating the greenhouse effect.
		( Image from NASA: CO₂ concentration in the atmosphere )
	What will be the main consequences of greenhouse effect ? There is no dispute about the human responsibility on the greenhouse effect, but much is still debated on its possible consequences. The most authoritative studies have been carried out on behalf of UN by IPCC (Intergovernmental Panel on Climate Change); according to a report by this Committee, underwritten by hundred of scientists (IPCC WGI Third Assessment Report - SPM, issued in January 2001) , the Earth is really warming : - the global average surface temperature has increased over the 20th century by about 0.6 °C . Globally, it is very likely that the 1990s was the warmest decade and 1998 the warmest year in the instrumental record, since 1861 . - According to British scientists, 2005 has been the warmest year in the Northern Hemisphere, and the second warmest globally since 1861. - Satellite data show decreases of about 10% in the extent of snow cover since the late 1960s. In particular equatorial snows and glaciers are disappearing quickly, on the Peruvian Ands and in Africa (33% of Kilimanjaro ices has melted over the past 20 years); the thickness of Arctic sea-ice in late summer is decreased. - Warming of the whole Anctartica has not been demonstrated; but in West Anctartica, specially in the Antarctica Peninsula (southern of the Latin America), massive landslides of enormous icy areas forming icebergs are observed. It is not clear if this process is related to the greenhouse effect or if it is the result of regional climatic changes.
		Image from the Modis satellite, by Nasa (An enormous ice sheet, 3250 sqkm wide, collapses from Larsen B platform, Antarctica Peninsula, forming icebergs; March 19, 2002)
	-Global average sea level has risen, mainly due to the thermal expansion of seas ( ice retreat is not the main reason): the increase over the 20th century has been between 10 and 20 centimeters. Global Climatic Trend : Projections until 2100. The projections of the IPCC, carried out with greatly improved methods compared to the past, indicate big increase in atmospheric CO₂ concentration due to human activity, with significant climatic consequences : - The globally averaged surface temperature is projected to increase by 1.4 to 5.8°C over the period 1990-2100: the rate of warming, too, should increase compared to last century. Warming should be most notable in some areas of our planet (northern regions of North America, northern and central Asia). - Heat waves, droughts, drier soils. - Increased evaporation and precipitation due to higher energy in the atmosphere : more frequent and extreme weather events ( storms, tornados, hurricanes ). -Sea levels will go on raising: erosion of sandy beaches or flooding of coastal areas (e.g., Bangla Desh, Nile Delta) and small islands (specially the atolls in South Pacific). -Easier transmission of some infectious diseases, including malaria and yellow fever . How long will Climate Change last ? The emissions of the most persistent greenhouse gases (carbon dioxide, nitrogen protoxide, perfluorocarbons) have a lasting effect on the climate : e.g., about a quarter of carbon dioxide persists in the atmosphere several centuries after the emission. Even if greenhouse gases concentration could be stabilized, the average surface temperatures and sea level would go on rising for centuries, due to the fact that deep Oceans follow climatic variations with big delay. Actions against greenhouse effect The following actions have been suggested to reduce greenhouse gas effect: - Energy saving ; using energy renewable sources (sun, wind, hydropower, geothermal, biomasses) or, among fossil fuels, prefer natural gases to oil or coal ( light hydrocarbons combustion is producing less carbon dioxide). - Gradual elimination of CFCs , see our page about Ozone Depletion - Planting new forests, saving the old ones.

Kyoto Protocol

Kyoto Protocol is an international agreement, underwritten in 1997 from 84 countries, committing developed countries to reducing their overall emissions of greenhouse gases . The Protocol was finally ratified by 146 countries and came into effect in January 2005.
An average 5% cut of greenhouse gases emissions has been fixed within 2012, compared to 1990 emissions level. Each country took on a different percentage target within this overall target.
An average 5% cut would be a great result ( many countries should reduce their emissions instead of increasing them sharply), but unfortunately not enough to stop the temperature increase; for this reason the term "climate change mitigation" is often used.

Which gases and which countries

Six greenhouse gases are mentioned in the agreement: carbon dioxide, methane, nitrogen protoxide, perfluorocarbons, hydrofluorocarbons and sulfur hexafluoride . Emission limits are foreseen for 39 industrialised countries; among them, starting from the largest global warming polluters :

USA
European Union (15 countries)
Russia
Japan
Canada
Poland
Bulgaria and other East European countries
Switzerland
Norway

Note

Kyoto Protocol does not mention CFCs (chlorofluorocarbons) because they are already regulated in the Montreal Protocol .

The USA (the world's top air polluter representing 36% of 1990 emissions) and Australia ( with a large coal industry) have stated that they will not join the Protocol. The Protocol will receive support from participating countries that emit 61,6% of carbon dioxide emissions.

The flexibility mechanisms

In order to get the targets agreed in Kyoto, it is possible to act on gas emissions at local, national or transnational level.

Three instruments are foreseen in the Protocol:

- Emission trading : Forests planted since 1990 are counted as carbon sinks ( they theoretically adsorb carbon from the atmosphere), and as credits that offset required cuts in emissions. Also renewable energy projects ( solar or wind ), or improvings to existing energy generation can be considered.
Industrialized countries can buy and sell emission permits, in order to find the cheapest way to cut emissions.
The European Union Emission Trading Scheme is the largest multi-national, greenhouse gas emissions trading scheme in the world. It commenced operation in January 2005 and all 25-member states of the European Union participate in the scheme.
-Joint Implementation and Clean Development Mechanism: They aim at maximizing the cost-effectiveness of climate change mitigation of industrialized countries by allowing them to take up opportunities to cut greenhouse gas emissions by investing in sustainable development projects in foreign countries. Joint Implementation projects are mostly intended for East Europe and Russia, however theoretically they can take place with every country with a reduction commitment ( industrialized countries); Clean Development Mechanism projects allows industrialized countries to fund projects that reduce emissions in developing countries instead of reducing pollution at home. .

The flexibility mechanisms are considered supplementary compared to the domestic actions.

According to the United Nations Climate Change Secretariat, the Kyoto Protocol's clean development mechanism (CDM) is estimated to generate more than one billion tonnes of emissions reductions by the end of 2012 : "It is now evident that the Kyoto Protocol is making a significant contribution towards sustainable development in developing countries" ( UNFCC Press Release, June 2006 )

Adverse Criticism to the Kyoto Protocol

The main objection is concerning the effectiveness of the Protocol : even the full implementation of the agreement would have a limited impact at very high costs; in any case we have to be prepared to some degree of climate change.

Another objection comes mainly from the USA, and is related to the fact that practically no sacrifice is requested to developing countries, due to the so called "Responsibility Principle ": the industrialised countries, as the main source of the greenhouse effect, should be the first to take steps to control emissions.

The flexibility mechanisms are often criticized. For instance, they don't consider carbon debts for old forests destruction, but only carbon credits for planting new forests.
Recently, anyway, a spontaneous market for emission permits has been created, mainly due to US companies.