Paris Agreement climate proposals need a boost to keep warming well below 2 °C

Abstract

-a new global agreement to combat climate change-was adopted under the United Nations Framework Convention on Climate Change (UNFCCC). In preparation of this agreement, countries submitted national plans that spell out their intentions for addressing the climate change challenge after 2020 2 . These Intended Nationally Determined Contributions (INDCs) address a range of issues, which can relate to avoiding, adapting or coping with climate change, among other things. Nevertheless, targets and actions for reducing greenhouse gas (GHG) emissions are core components. At this point, the INDCs are not final and can be modified up until the time the Paris Agreement is ratified. However, for now they represent our best understanding of the climate actions countries intend to pursue after 2020.The overarching climate goal of the Paris Agreement is to hold "the increase in the global average temperature to well below 2 °C above preindustrial levels and to pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels" 1 . This climate goal represents the level of climate change that governments agree would prevent dangerous interference with the climate system, while ensuring sustainable food production and economic development 3,4 , and is the result of international discussions over multiple decades 5 . Limiting warming to any level implies that the total amount of carbon dioxide (CO 2 ) that can ever be emitted into the atmosphere is finite 6 . From a geophysical perspective, global CO 2 emissions thus need to become net zero 7,8 . About two thirds of the available budget for keeping warming to below 2 °C have already been emitted [9][10][11] , and increasing trends in CO 2 emissions 12 indicate that global emissions urgently need to start to decline so as to not foreclose the possibility of holding warming to well below 2 °C (refs 13, 14). The window for limiting warming to below 1.5 °C with high probability and without temporarily exceeding that level already seems to have closed 15 . The Paris Agreement implicitly acknowledges these insights and aims to reach a global peak in GHG emissions as soon as possible together with achieving "a balance" between anthropogenic emissions and removals of GHGs in the second half of this century. Both targets are in principle consistent with the temperature objective of the Agreement 16,17 , but beg the broader question of whether current INDCs are already putting the world on a path towards achieving them.Besides the climate question, the first round of INDCs also raises many other issues. These include whether efforts are distributed equitably among countries; how much adaptation may be required given the current level of mitigation ambition; how 'intended' national proposals will be implemented; how they will be financed; and the extent to which the INDCs contribute to the achievement of other goals of the UNFCCC by building on institutions that can support adaptation to climate change, technology advancement, development path transformation, sustainable...

The safe carbon budget

“…My aim is not to come up with the best numbers for climate policy as this is better left for the much more detailed integrated assessment models (IAMs) (e.g., Clarke et al 2014). The climate policy/science literature has already addressed the need to tighten climate policy in the light of the 1.5°C target (e.g., Kriegler et al 2014;Tahvoni et al 2015;Rogelj et al 2015Rogelj et al , 2016, the FEEM Limits Project, the 2016 SSP data base on shared socioeconomic pathways, comparison exercises reported in IPCC studies , and studies that deal with carbon prices consisting of the CPW only (e.g., Bauer et al 2015). My analysis is complementary and more modest in that it builds a bridge between the economics literature based on production damages and the climate policy/science literature on temperature constraints.…”

Deep Coal Mine Methane Drainage in China with Lower Greenhouse Gas Emissions: Insights of Borehole Protection Technology

“…For the three main greenhouse gasses, the global warming potential and ozone depletion potential of CH 4 are about 23 times and 7 times higher than that of CO 2 per unit mass. In China, methane has the second greatest radiative forcing among the long-lived greenhouse gasses after carbon dioxide, accounting for 19.7% of Chinese anthropogenic greenhouse gas emissions [2].…”

“…C LIMaTE warming has currently been one of the most important global environmental issues, which is induced by the increasing greenhouse gasses (CO 2 , CH 4 and N 2 O) in the atmosphere [1]. For the three main greenhouse gasses, the global warming potential and ozone depletion potential of CH 4 are about 23 times and 7 times higher than that of CO 2 per unit mass.…”

“…CMM is a general term for all methane released mainly during and after mining operations, accounting for more than half of the nation's methane released volume [3]. Thus, reducing CMM emission is of vital importance to realize the Paris Climate Agreement of keeping warming well below 2°C [4].…”

Forecasting Global Warming

“…Shaded regions represent contributions from specific gases or groups. See Methods for further information most recent IPCC report (Rogelj et al 2016), below we show these GCMs likely over-estimate the actual warming that will occur in the coming decades. Figure 2.3 shows projections of ΔT from the CMIP5 GCMs found using RCP 4.5 and RCP 8.5.…”