Global carbon emissions may be plateauing: Global Carbon Project
Global CO2 emissions could be plateauing, according to a report by the Global Carbon Project. The report shows the world's two worst offenders, the US and China, reduced CO2 emissions by 1.7% and 0.5% respectively in 2016 and estimated the global rise would be 0.2% for this year, despite India's levels rising by 5.2%. However, the report did not include levels of other greenhouse gases nor emissions from non-industrial sources, and CO2 emissions remain 63% higher than 1990 levels.
Corinne Le Quéré , Robbie M. Andrew , Josep G. Canadell , Stephen Sitch , Jan Ivar Korsbakken , Glen P. Peters , Andrew C. Manning , Thomas A. Boden , Pieter P. Tans , Richard A. Houghton , Ralph F. Keeling , Simone Alin , Oliver D. Andrews , Peter Anthoni , Leticia Barbero , Laurent Bopp , Frédéric Chevallier , Louise P. Chini , Philippe Ciais , Kim Currie , Christine Delire , Scott C. Doney , Pierre Friedlingstein , Thanos Gkritzalis , Ian Harris , Judith Hauck , Vanessa Haverd , Mario Hoppema , Kees Klein Goldewijk , Atul K. Jain , Etsushi Kato , Arne Körtzinger , Peter Landschützer , Nathalie Lefèvre , Andrew Lenton , Sebastian Lienert , Danica Lombardozzi , Joe R. Melton , Nicolas Metzl , Frank Millero , Pedro M. S. Monteiro , David R. Munro , Julia E. M. S. Nabel , Shin-ichiro Nakaoka , Kevin O'Brien , Are Olsen , Abdirahman M. Omar , Tsuneo Ono , Denis Pierrot , Benjamin Poulter , Christian Rödenbeck , Joe Salisbury , Ute Schuster , Jörg Schwinger , Roland Séférian , Ingunn Skjelvan , Benjamin D. Stocker , Adrienne J. Sutton , Taro Takahashi , Hanqin Tian , Bronte Tilbrook , Ingrid T. van der Laan-Luijkx , Guido R. van der Werf , Nicolas Viovy , Anthony P. Walker , Andrew J. Wiltshire , and Sönke Zaehle

Abstract. Accurate assessment of anthropogenic carbon dioxide (CO 2 ) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the “global carbon budget” – is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates and consistency within and among components, alongside methodology and data limitations. CO 2 emissions from fossil fuels and industry (E FF ) are based on energy statistics and cement production data, respectively, while emissions from land-use change (E LUC ), mainly deforestation, are based on combined evidence from land-cover change data, fire activity associated with deforestation, and models. The global atmospheric CO 2 concentration is measured directly and its rate of growth (G ATM ) is computed from the annual changes in concentration. The mean ocean CO 2 sink (S OCEAN ) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in S OCEAN is evaluated with data products based on surveys of ocean CO 2 measurements. The global residual terrestrial CO 2 sink (S LAND ) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models. We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1σ, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2006–2015), E FF was 9.3 ± 0.5 GtC yr−1, E LUC 1.0 ± 0.5 GtC yr−1, G ATM 4.5 ± 0.1 GtC yr−1, S OCEAN 2.6 ± 0.5 GtC yr−1, and S LAND 3.1 ± 0.9 GtC yr−1. For year 2015 alone, the growth in E FF was approximately zero and emissions remained at 9.9 ± 0.5 GtC yr−1, showing a slowdown in growth of these emissions compared to the average growth of 1.8 % yr−1 that took place during 2006–2015. Also, for 2015, E LUC was 1.3 ± 0.5 GtC yr−1, G ATM was 6.3 ± 0.2 GtC yr−1, S OCEAN was 3.0 ± 0.5 GtC yr−1, and S LAND was 1.9 ± 0.9 GtC yr−1. G ATM was higher in 2015 compared to the past decade (2006–2015), reflecting a smaller S LAND for that year. The global atmospheric CO 2 concentration reached 399.4 ± 0.1 ppm averaged over 2015. For 2016, preliminary data indicate the continuation of low growth in E FF with +0.2 % (range of −1.0 to +1.8 %) based on national emissions projections for China and USA, and projections of gross domestic product corrected for recent changes in the carbon intensity of the economy for the rest of the world. In spite of the low growth of E FF in 2016, the growth rate in atmospheric CO 2 concentration is expected to be relatively high because of the persistence of the smaller residual terrestrial sink (S LAND ) in response to El Niño conditions of 2015–2016. From this projection of E FF and assumed constant E LUC for 2016, cumulative emissions of CO 2 will reach 565 ± 55 GtC (2075 ± 205 GtCO 2 ) for 1870–2016, about 75 % from E FF and 25 % from E LUC . This living data update documents changes in the methods and data sets used in this new carbon budget compared with previous publications of this data set (Le Quéré et al., 2015b, a, 2014, 2013). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_2016).