Climate change is one of the greatest environmental, social and economic threats facing the planet.

The warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level. The Earth's average surface temperature has risen by 0.76° C since 1850. Most of the warming that has occurred over the last 50 years is very likely to have been caused by human activities.








Click image to view: global mean surface temperature anomaly 1850 to 2006 relative to 1961–1990

Projected global warming this century is likely to trigger serious consequences for humanity and other life forms, including a rise in sea levels of between 18 and 59 cm which will endanger coastal areas and small islands, and a greater frequency and severity of extreme weather events.

Human activities that contribute to climate change include in particular the burning of fossil fuels, agriculture and land-use changes like deforestation. These cause emissions of carbon dioxide (CO2), the main gas responsible for climate change, as well as of other 'greenhouse' gases. To bring climate change to a halt, global greenhouse gas emissions must be reduced significantly.

Click image to view: carbon dioxide during the last 400,000 years and (inset above) the rapid rise since the Industrial Revolution; changes in the Earth's orbit around the Sun, known as Milankovitch cycles, are believed to be the pacemaker of the 100,000 year ice age cycle.

Warming trend

During the last century, the average surface air temperature increased by 0.6ºC globally and by almost 1ºC in Europe, which is unusually rapid warming. In fact, the 20th century was the warmest century and the 1990s were the warmest decade in the past 1,000 years. This warming trend has continued into this century. According to NASA, the five warmest years on record have been, in this order:

1. 2005
2. 1998
3. 2002
4. 2003
5. 2004

The Intergovernmental Panel on Climate Change (IPCC) - a scientific forum set up in the framework of the United Nations in 1988 to bring together thousands of climate experts from across the world - predicts that global average temperature will further increase by 1.4 to 5.8°C by 2100 as a result of human activities. This might not seem like much of a difference, but during the last Ice Age over 11,500 years ago, the average global temperature was only 5°C lower than the current temperature, and that was when most of Europe was covered by a thick layer of ice!

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Already, climate change is having many discernible impacts, ranging from the increases in temperature to rising sea levels as a result of melting polar ice caps and more frequent storms and floods. If we do not take action, climate change will cause more and more costly damage and disrupt the functioning of our natural environment, which supplies us with food, raw materials and other vital resources. This will negatively affect our economies and could destabilise societies around the globe.

Understanding climate change

Energy from the sun warms the earth's surface and, as the temperature increases, heat is radiated back into the atmosphere as infra-red energy. Some of the energy is absorbed within the atmosphere by 'greenhouse gases'. The atmosphere acts in a similar way to the walls of a greenhouse, letting in the visible light and absorbing the outgoing infra-red energy, keeping it warm inside. This natural process is called the "greenhouse effect." Without it, the global average temperature on earth would be -18°C, whereas at the moment it is +15°C.

However, human activities are adding greenhouse gases, particularly carbon dioxide, methane and nitrous oxide, to the atmosphere, which are enhancing the natural greenhouse effect and making the world warmer. This man-made extra warming is called the "enhanced" greenhouse effect.

Fighting Climate Change

The United Nations Framework Convention on Climate Change (UNFCCC) and its Kyoto Protocol provides the global institutional framework for tackling climate change, defining the objective of the efforts, as well as the key principles for reaching it.

One of the key principles of the UNFCCC is that of "common but differentiated responsibilities", which requires developed countries to take the lead in the fight against climate change and its impacts. By differentiating between developed and developing countries, the UNFCCC recognises that developed, industrialised countries are responsible for most of the current build-up of greenhouse gases in the atmosphere and have the financial and technological resources to reduce their emissions.

It is likely that 75% of the glaciers in the Swiss Alps will have disappeared by 2050 and many of your favourite skiing resorts have already resorted in buying fake snow.



Alpine Glacier: comparison of 1900 to present Pasterze Glacier in Kärtnen, Austria

Photo Source: Munich Society for Environmental Research

The UNFCCC obliges its parties to establish national programmes for reducing greenhouse gas emissions and to submit regular reports. It also required the industrialised countries among the parties - but not developing countries - to stabilise their greenhouse gas emissions at 1990 levels by the year 2000, in which they succeeded as a group. The UNFCCC parties meet annually to review progress and discuss further measures, and a number of global monitoring and reporting mechanisms are in place to keep track of greenhouse gas emissions.

The Kyoto Protocol

Governments knew that the efforts of the UNFCCC would not be enough to seriously tackle climate change. On 11 December 1997, they took a further step and adopted a protocol to the UNFCCC in the Japanese town of Kyoto: the Kyoto Protocol. Building on the UNFCCC framework, the protocol sets legally binding limits on greenhouse gas emissions from 37 industrialised countries originally, including all Member States of the European Union except Cyprus and Malta, as well as from the EU as one single body (known as the EU-15, since it then had only 15 member countries.) It also introduces innovative market-based implementation mechanisms - the so-called Kyoto flexible mechanisms - aimed at keeping the cost of curbing emissions low. Studies have suggested that sea levels may rise from 88cm and up to 6 meters by 2100!

Under the Kyoto Protocol, industrialised countries are required to reduce their emissions of six greenhouse gases (CO2, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride) by around 5% below the 1990 level during the first Kyoto Protocol "commitment period" from 2008 to 2012. A five-year commitment period was chosen rather than a single target year to smooth out annual fluctuations in emissions due to uncontrollable factors such as weather. There are no emission targets for developing countries.

The Kyoto Protocol entered into force on 16 February 2005. The rules for its entry into force required that at least 55 Parties to the UNFCCC ratify the protocol and that those include industrialised countries accounting for at least 55% of the industrialised countries' CO2 emissions in 1990, which took a while to achieve.

As of 18 April 2006, 162 states and the European Community had ratified the protocol. Two countries that originally signed the treaty have not ratified: the US has rejected the protocol, whereas Australia has decided not to ratify it. This means there are 36 developed countries and the EU-15 as an entity that are obliged to reach their Kyoto targets.

However, Kyoto is only a first step. Ambitious action to reduce global emissions is needed after 2012, when Kyoto's targets expire, in order to limit global warming to 2°C.

source: European Commission, You Control Climate Change