Global warming is a global problem. To understand it, cope with it and try to keep it from getting worse, all the countries of the world need to work together.

And when nations need to unite, they turn to the United Nations.

The United Nations is playing a central role in clarifying the science of global warming and preparing a global plan of action to deal with it. Because UN organizations like FAO are neutral, their scientific and technical reports are trusted and they can negotiate agreements among countries with different political viewpoints and economic interests.

The process of global warming began more than a century ago. Our response has just begun. Here’s a timeline of the major events in the UN’s efforts to help the countries of the world deal with global warming.

1988 - Intergovernmental Panel on Climate Change (IPCC)

Two United Nations organizations – the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) – establish the Intergovernmental Panel on Climate Change (IPCC). The Panel doesn’t do its own research. Its job is to bring clarity to the highly political and controversial debate over global warming and its causes.

It prepares comprehensive, objective, and transparent assessments of the state of international research on climate change, its causes and its consequences.

1990 – The IPCC’s first assessment

The Panel’s first assessment confirms that global warming is a reality, and that it is caused by an accumulation of greenhouse gases released into the atmosphere by human activities.

Find out more about the science of global warming.

On the basis of this assessment, the UN General Assembly calls for countries to negotiate an international agreement to address global warming.

1992 – UN Framework Convention on Climate Change

Countries belonging to the United Nations ratify the Framework Convention on Climate Change. Under this voluntary agreement, countries agree to share information and establish national action plans for reducing greenhouse gas emissions. Industrialized countries also agree to help developing countries with technologies for generating power using renewable energy, and help them adapt to the expected environmental changes.

1995 – IPCC’s second assessment

The Intergovernmental Panel on Climate Change releases its second assessment. World leaders recognize that the Framework Convention isn’t strong enough to seriously attack global warming. They begin negotiations to establish a legally binding agreement for reducing greenhouse gas emissions.

1997 – The Kyoto Protocol

Member countries of the UN Framework Convention on Climate Change negotiate the Kyoto Protocol. Under the Protocol, each country agrees to reach a national reduction target. The combined effort of all countries is expected to cut total greenhouse-gas emissions by at least 5 percent from 1990 levels by 2008-2012.

Included in the Kyoto Protocol is something called the Clean Development Mechanism. This allows industrialized countries to get “credits” for emission reductions by sponsoring greenhouse-gas-reducing projects in developing countries. These projects help countries generate power using renewable energy resources or increase their capacity to absorb greenhouse gases, primarily by expanding their forest cover.

Negotiating the text of this agreement was only the beginning. Before it becomes binding, it must be signed by at least 55 countries, including enough industrialized countries to account for 55 percent of the world's greenhouse gases.

2001 – USA withdraws support for the Kyoto Protocol

The United States withdraws its support for the Protocol, arguing that the economic costs are too great compared to the benefits. It also claims that large developing countries like China and India should be obliged to reduce their emissions as well.

Because the United States emits about one quarter of the world’s greenhouse gases, many worry that without US compliance, the Kyoto Protocol will have little effect on reducing emissions.

Australia withdraws its support the following year.

2005 – The Kyoto Protocol enters into force

The Kyoto Protocol enters into force in February, 90 days after Russia signed on.

Italy is one of the first countries to receive “emission control credits” through the Protocol’s Clean Development Mechanism, thanks to its participation in a hydroelectric project in Honduras.

The future?

The Kyoto Protocol was never intended to be the complete solution for dealing with global warming. But it marks an important step forward in an ongoing process to deal with this major environmental problem.

The Kyoto Protocol expires in 2012.