Chapter 2
The importance of pre-2020 action Section 2.2: Lead author: Joeri Rogelj (International Institute for Applied Systems Analysis) Contributing authors: Kejun Jiang (Energy Research Institute), Jason Lowe (Met Office), Greet Maenhout (Joint Research Centre, European Commission), Steven Smith (Pacific Northwest National Laboratory) Section 2.3: Lead authors: Taryn Fransen (World Resources Institute), Michel den Elzen (PBL Netherlands Environmental Assessment Agency), Hanna Fekete (NewClimate Institute), Niklas Höhne (NewClimate Institute) Contributing authors: Mengpin Ge (World Resources Institute), Heleen van Soest (PBL Netherlands Environmental Assessment Agency)
2.1 Introduction This Chapter first discusses recent global emission levels and trends, and reviews where global emissions would be heading in the absence of additional deliberate climate policies. It then presents assessment of global emission pathways that would keep global warming to below respectively 1.5°C or 2°C in 2100. This is followed by an elaboration of why enhanced early action matters and a discussion of the implications of not increasing short-term climate mitigation efforts.
increase in 2010-2011), the emissions growth slowed to 1.8 per cent on average over the subsequent two years1. The most recent global emission estimates2 are for the year 2014. In that year, total global Kyoto-GHG emissions3 amounted to about 52.7 GtCO2e/yr (range: 47.9-57.54, Figure 2.1). Global carbon dioxide (CO2) emissions from fossil fuels and industry alone were estimated at 35.5 GtCO2/yr5 for 2014 (range: 32.5-38.56).
Achievement of the Cancun 2020 pledges will be important for the transition to least-cost mitigation pathways from 2020. Section 2.3 therefore takes a closer look at progress towards achieving the 2020 pledges. The focus is on the Parties that are members of the G20, as these economies collectively generate around three quarters of global GHG emissions. However, it remains critical that all countries advance as far as possible towards achieving – and ideally exceeding – their Cancun pledges.
In the absence of any further mitigation action compared to these trends, GHG emission projections are set to increase significantly over the 21st century. These projections are influenced by many factors. For example, economic and population growth will generally result in an increase in emissions, while energy intensity improvements in the global economy and reductions of carbon intensity in energy production will generally result in a decrease in emissions. These factors have characterized the last three decades of the 20th century. During the first decade of the 21st century, however, carbon intensity increased again, thus further contributing to rising global emissions.
2.2 Global emission pathways and the importance of enhanced action
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2.2.1 Recent trends and baselines
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Over the past decades, global GHG emissions have increased steadily with small variations around a longer term trend. Moreover, during the first decade of the 21st century, emissions increased at a faster rate (2.2 per cent/yr) than during the last three decades of the 20th century (1.3 per cent/yr) (IPCC, 2014a). After the recovery from the economic crisis (with a 3.5 per cent
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Based on EC-JRC/PBL. EDGAR version 4.3. http://edgar.jrc.ec.europa.eu/, 2015 update (forthcoming). Data for this year is available from EDGAR and PRIMAP. Sources: EC-JRC/PBL. EDGAR version 4.3. http://e gar.jrc.ec.europa.eu/, 2015 update (forthcoming), PRIMAP4 baseline: PIK-Potsdam. https://www. pik-potsdam.de/research/climate-impacts-and-vulnerabilities/research/rd2flagship-projects/primap/emissions-module Here aggregated with 100-year Global Warming Potentials (GWPs) of the IPCC Second Assessment Report. 90 per cent confidence interval, based on the uncertainty range assessed in IPCC AR5 Working Group III. Source: BP Statistical Review of World Energy June 2015, http://www. bp.com/statisticalreview 95 per cent uncertainty range, based on Andres et al. (2014).
The Emissions Gap Report 2015 – The importance of pre-2020 action
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