IPCC Fifth Assessment Report
[1] As had been the case in the past, the outline of the AR5 was developed through a scoping process which involved climate change experts from all relevant disciplines and users of IPCC reports, in particular representatives from governments.
[6][7] The Synthesis Report was released on 2 November 2014,[8] in time to pave the way for negotiations on reducing carbon emissions at the UN Climate Change Conference in Paris during late 2015.
[22] A key statement of the report was that:[9] Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems.
On 23 June 2010 the IPCC announced the release of the final list of selected coordinating lead authors, comprising 831 experts who were drawn from fields including meteorology, physics, oceanography, statistics, engineering, ecology, social sciences and economics.
In comparison to the Fourth Assessment Report (AR4), participation from developing countries was increased, reflecting the ongoing efforts to improve regional coverage in the AR5.
[24] The full, edited report was released online in January 2014 and published in physical form by Cambridge University Press later in the year.
[26] The principal findings were:[19] Climate model simulations in support of AR5 use a different approach to account for increasing greenhouse gas concentrations than in the previous report.
[19] Halldór Thorgeirsson, a UN official, warned that, because big companies are known to fund the undermining of climate science, scientists should be prepared for an increase in negative publicity at the time.
Jennifer Morgan, from the World Resources Institute, said "Hopefully the IPCC will inspire leadership, from the Mom to the business leader, to the mayor to the head of state.
"[37] US Secretary of State John Kerry responded to the report saying "This is yet another wakeup call: those who deny the science or choose excuses over action are playing with fire.
The higher our emissions, the larger climate changes we'll face, which also means more expensive adaptation, more species extinctions, more food and water insecurities, more income losses, more conflicts, and so forth.The New York Times reported that:[40] In Washington, President Obama's science adviser, John P. Holdren, cited increased scientific confidence "that the kinds of harm already being experienced from climate change will continue to worsen unless and until comprehensive and vigorous action to reduce emissions is undertaken worldwide.
"It went on to say that Ban Ki-moon, the United Nations secretary general, had declared his intention to call a meeting of heads of state in 2014 to develop such a treaty.
