IPCC: Working and Reports.

The Intergovernmental Panel on Climate Change (IPCC) is a scientific intergovernmental body under the auspices of the United Nations,set up at the request of member governments.It was first established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), and later endorsed by the United Nations General Assembly through Resolution 43/53. Membership of the IPCC is open to all members of the WMO and UNEP.The IPCC is chaired by Rajendra K. Pachauri.

The IPCC produces reports that support the United Nations Framework Convention on Climate Change (UNFCCC), which is the main international treaty on climate change. 

What is UNFCCC?

The UNFCCC is an international environmental treaty negotiated at the United Nations Conference on Environment and Development (UNCED), informally known as the Earth Summit, held in Rio de Janeiro from 3 to 14 June 1992. The objective of the treaty is to "stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system".The ultimate objective of the UNFCCC is to "stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic [i.e., human-induced] interference with the climate system". 

Working of IPCC.

It does not carry out new research nor does it monitor climate-related data.   

• It meets in plenary sessions about once a year to decide on the work plans of theWorking Groups and the Task Force on National Greenhouse Gas Inventories. To ensure the study on issues of climate change and its implications from the broadest perspective, the IPCC divides its work among three Working Groups and a special task force. The three Working Groups task force cover: 

1. The Physical Basis of Climate Change- it assesses the scientific aspects of the climate system and climate change.   
2. Climate Change Impacts, Adaptation and Vulnerability- it assesses the vulnerability of socio-economic and natural systems to climate change, negative and positive consequences of climate change and options for adapting.  
3. Mitigation of Climate Change- assesses options for limiting greenhouse gas emissions and otherwise mitigating climate change. 
4. The Task Force on National Greenhouse Gas Inventories is responsible for the IPCC National Greenhouse Gas Inventories Programme.    

• Reports developed by each each of these bodies go through an extensive, multi-level review process. Reviewers typically represent more than 150 countries as well as a wide range of public and private sector organizations.  
• Hundreds of the world’s top scientists work to develop the IPCC Assessment Reportsthrough critically analyzing and synthesizing the best scientific, technical and socio-economic information available in peer-reviewed and internationally available literature.   
• Their findings are then extensively reviewed by an independent group of scientists and then, after revision, by a wide range of interested parties. Experts in interpreting scientific matters for government leaders work with the scientific authors to carefully and effectively convey this information to policy-makers.    
• Because the IPCC is an intergovernmental body, IPCC reports are reviewed by governments as well as experts. As drafts are prepared and finalized, comments received from both are taken into account by lead authors - sometimes altering the text, sometimes refining the text, and sometimes answering the comment and not changing the text.   
• This rigorous process has produced a series of major assessments and special reports that have been unanimously agreed upon by all of the countries and by all of the leading scientists serving as lead authors. 

Findings: IPCC Assessment Reports.

Since 1990, the IPCC has published its findings in Assessment Reports (ARs). Each comprehensively covers the many implications of climate change, including scientific, technical and socio-economic aspects. The Assessment Reports consists of reviews of the state of scientific understanding from three Working Groups and an integrating Synthesis Report that directly addresses key questions raised by policymakers. 

1. The First Assessment Report (FAR) of the Intergovernmental Panel on Climate Change (IPCC) was completed in 1990. It served as the basis of the United Nations Framework Convention on Climate Change (UNFCCC). Its key findings were:
• there is a natural greenhouse effect...; emissions resulting from human activities are substantially increasing the atmospheric concentrations of the greenhouse gases: CO₂, methane, CFCs and nitrous oxide.
• CO₂ has been responsible for over half the enhanced greenhouse effect; 
• Increase of global mean temperature during the [21st] century of about 0.3 ^oC per decade (with an uncertainty range of 0.2 to 0.5 ^oC per decade); this is greater than that seen over the past 10,000 years;
• global mean surface air temperature has increased by 0.3 to 0.6 ^oC over the last 100 years...; 
• an average rate of global mean sea level rise of about 6 cm per decade over the next century (with an uncertainty range of 3 – 10 cm per decade), mainly due to thermal expansion of the oceans and the melting of some land ice. The predicted rise is about 20 cm ... by 2030, and 65 cm by the end of the next century. 

2. Second Assessment Report (SAR), 1995. The final version of Chapter 8 of the SAR stated that "these results indicate that the observed trend in global mean temperature over the past 100 years is unlikely to be entirely natural in origin. More importantly, there is evidence of an emerging pattern of climate response to forcings by greenhouse gases and sulphate aerosols in the observed climate record. Taken together, these results point towards a human influence on global climate." 
3. Third Assessment Report (TAR), Climate Change 2001.The TAR Synthesis Report includes a summary of the TAR's main findings and uncertainties. "Robust findings" of the TAR include:
• Observed warming of the Earth's surface, attribution of observed warming to human activities, projected increases in future global mean temperature, rising sea levels, and increased frequency of heat waves.
• Future warming will have both beneficial and adverse effects, but for higher levels of warming, adverse effects will predominate.


• Developing countries and poor persons are most vulnerable to climate change.
4. Climate Change 2007, the Fourth Assessment Report (AR4). It is a series of reports intended to assess scientific, technical and socio-economic information concerning climate change, its potential effects, and options for adaptation and mitigation. The report is the largest and most detailed summary of the climate change situation ever undertaken, produced by thousands of authors, editors, and reviewers from dozens of countries, citing over 6,000 peer-reviewed scientific studies. It made following observations:

Changes in the atmosphere.

• Increase in Carbon dioxide, methane, and nitrous oxide as a result of human activities since 1750. The primary source of the increase in carbon dioxide is fossil fuel use, but land-use changes also make a contribution.
• Increase in the amount of methane in the atmosphere in 2005 exceeding by far the natural range of the last 650,000 years. The primary source of the increase in methane is very likely to be a combination of human agricultural activities and fossil fuel use. How much each contributes is not well determined.
• Nitrous oxide concentrations have raised from a pre-industrial value with more than a third of this rise, due to human activity, primarily agriculture.

Warming of the planet.

• Cold days, cold nights, and frost events have become less frequent. Hot days, hot nights, and heat waves have become more frequent. 
• Eleven of the twelve years in the period (1995–2006) rank among the top 12 warmest years in the instrumental record (since 1880).
• Warming in the last 100 years has caused about a 0.74 °C increase in global average temperature. This is up from the 0.6 °C increase in the 100 years prior to the Third Assessment Report.
• Urban heat island effects were determined to have negligible influence (less than 0.0006 °C per decade over land and zero over oceans) on these measurements.
• Observations since 1961 show that the ocean has been absorbing more than 80% of the heat added to the climate system, and that ocean temperatures have increased to depths of at least 3000 m (9800 ft).
• "Average Arctic temperatures increased at almost twice the global average rate in the past 100 years."
• It is likely that greenhouse gases would have caused more warming than we have observed if not for the cooling effects of volcanic and human-caused aerosols. See global dimming.
• Average Northern Hemisphere temperatures during the second half of the 20th century were very likely higher than during any other 50-year period in the last 500 years and likely the highest in at least the past 1300 years (including both the Medieval Warm Period and the Little Ice Age).

Ice, snow, permafrost, rain, and the oceans.

• The SPM documents increases in wind intensity, decline of permafrost coverage, and increases of both drought and heavy precipitation events. 
• "Mountain glaciers and snow cover have declined on average in both hemispheres."
• Losses from the land-based ice sheets of Greenland and Antarctica have very likely (>90%) contributed to sea level rise between 1993 and 2003.
• Ocean warming causes seawater to expand, which contributes to sea level rising.
• Sea level rose at an average rate of about 1.8 mm/year during the years 1961–2003. The rise in sea level during 1993–2003 was at an average rate of 3.1 mm/year. It is not clear whether this is a long-term trend or just variability.
• Antarctic sea ice shows no significant overall trend, consistent with a lack of warming in that region.

Hurricanes.

• There has been an increase in hurricane intensity in the North Atlantic since the 1970s, and that increase correlates with increases in sea surface temperature.
• The observed increase in hurricane intensity is larger than climate models predict for the sea surface temperature changes we have experienced.
• There is no clear trend in the number of hurricanes.
• Other regions appear to have experienced increased hurricane intensity as well, but there are concerns about the quality of data in these other regions.
• It is more likely than not (>50%) that there has been some human contribution to the increases in hurricane intensity.
• It is likely (>66%) that we will see increases in hurricane intensity during the 21st century.

Importance of Reports.

The scientific evidence brought up by the first IPCC Assessment Report of 1990 underlined the importance of climate change as a challenge requiring international cooperation to tackle its consequences. It therefore played a decisive role in leading to the creation of the United Nations Framework Convention on Climate Change (UNFCCC), the key international treaty to reduce global warming and cope with the consequences of climate change. 
Since then the IPCC has delivered on a regular basis the most comprehensive scientific reports about climate change produced worldwide, the Assessment Reports. It has also responded to the need for information on scientific and technical matters from the UNFCCC, through Methodology Reports and Special Reports, and from governments and international organizations through Special Reports and Technical Papers. Methodology Reports serve as methodologies and guidelines to help Parties to the UNFCCC prepare their national greenhouse gas inventories. 
 
The IPCC Second Assessment Report of 1995 provided important material drawn on by negotiators in the run-up to adoption of the Kyoto Protocol in 1997.