Summary for Policymakers

The Summary for policymakers (SPM) is a summary of the Intergovernmental Panel on Climate Change (IPCC) reports intended to aid policymakers. The form is approved line by line by governments: "Negotiations occur over wording to ensure accuracy, balance, clarity of message, and relevance to understanding and policy."

The IPCC is divided into 3 "Working Groups" (WG) covering a section of the climate change (global warming) topic:

Approximately every 5 years, each Working Group prepares a full "assessment report" by collating all the available research results.

Before the end of this period, a selection of about 50 scientists within each Working Group produces a first draft "Summary for policymakers" (SPM) summarizing its section of the full assessment report. This first draft SPM is sent for comments to the participating government. Comments are taken into account in a second draft prepared by the scientists. When the full assessment report is finalized, each second draft SPM is then reviewed during a four days plenary session comprising government delegations and observer organizations. Each reviewing session is chaired by the scientists chairing the Working Group, surrounded by a panel of scientists. The government delegations usually consist of one to six delegates, comprising generally a mix of national experts (some of which are part of the IPCC) and a few diplomats or other non-scientist civil servants.

The objective of the review session is to improve the form of the SPM, which must remain faithful to the scientific content of the full assessment report. This process also results in some form of endorsement by the participating governments.

For the Fourth Assessment SPMs, each review lasted three days. The beginning of the first day was open to journalists and started with introductory speeches (from the IPCC President, local politicians...). Then each sentence of the draft SPM, displayed on a giant screen, was discussed at length by the delegates and often ended up completely rewritten. Some paragraphs were removed and others are added, under the full control of the Chair and its panel of scientist who ensured that every sentence strictly conforms to the content of the full assessment. When the discussion on a sentence lasted too long, a subgroup chaired by a scientist was formed to craft aside a revised text for later submission to the plenary. Generally the process was very slow at the beginning: in some cases, as little as a few paragraphs were reviewed at the end of the first day. The review generally ended late in the night of the third day - sometimes even in the next morning. On the fourth day, the reviewed SPM was released during a closing session open to journalists.

...
Wikipedia