The link between a global 2 °C warming threshold and emissions in years 2020, 2050 and beyond

Bibliographic Data

ID15544993
AuthorsChris Huntingford (0000-0002-5941-7770, UK Centre for Ecology & Hydrology, corresponding author), Jason Lowe (0000-0002-8201-3926, Met Office), Jason A Lowe, Laila Gohar (0000-0003-1332-1746, Met Office), Laila K Gohar, Niel Bowerman (University of Oxford), Niel H A Bowerman, Myles Allen (0009-0004-5372-0738), Myles R Allen (0000-0002-1721-7172, University of Oxford), Sarah C B Raper, Stephen M Smith (0000-0001-8166-069X, Committee on Climate Change)
Year2012
Volume7
Issue1
Pages014039-014039
Publication date2012-03-01
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueEnvironmental Research Letters (JOURNAL)
Journal identifiersISSN: 1748-9326 • E-ISSN: 1748-9326
PublisherIOP Publishing (PUBLISHER • GB)
DOI10.1088/1748-9326/7/1/014039
OpenAlexW2161716319
LanguageEN
Citations received10
References cited29

In the Copenhagen Accord, nations agreed on the need to limit global warming to two degrees to avoid potentially dangerous climate change, while in policy circles negotiations have placed a particular emphasis on emissions in years 2020 and 2050. We investigate the link between the probability of global warming remaining below two degrees (above pre-industrial levels) right through to year 2500 and what this implies for emissions in years 2020 and 2050, and any long-term emissions floor. This is achieved by mapping out the consequences of alternative emissions trajectories, all in a probabilistic framework and with results placed in a simple-to-use set of graphics. \n \nThe options available for carbon dioxide-equivalent (CO2e) emissions in years 2020 and 2050 are narrow if society wishes to stay, with a chance of more likely than not, below the 2 °C target. Since cumulative emissions of long-lived greenhouse gases, and particularly CO2, are a key determinant of peak warming, the consequence of being near the top of emissions in the allowable range for 2020 is reduced flexibility in emissions in 2050 and higher required rates of societal decarbonization. Alternatively, higher 2020 emissions can be considered as reducing the probability of limiting warming to 2 °C. We find that the level of the long-term emissions floor has a strong influence on allowed 2020 and 2050 emissions for two degrees of global warming at a given probability. We place our analysis in the context of emissions pledges for year 2020 made at the end of and since the 2009 COP15 negotiations in Copenhagen

Climate change · Climate policy · Climatology · Economics · Geography · Global temperature · Global warming · Greenhouse gas · Meteorology · Natural resource economics · Negotiation · Political science · Term (time · Atmospheric and Environmental Gas Dynamics · Atmospheric chemistry and aerosols · Climate Change Policy and Economics · Environmental Science · Ecology