The Paris Agreement on climate change is being, rightly, hailed as a stepping-stone for collective action. It is by no means a perfect agreement, nor entirely a fair one. But it moves the needle decisively in terms of ambition, progression of intended actions, monitoring and review, and the desire to work together to develop new solutions. However, the most ambitious part of the agreement - limiting temperature rise - will be the hardest to achieve.
The agreement lends top-down multilateral legitimacy to the bottom-up, self-determined Intended Nationally Determined Contributions (INDCs), or plans (up to 2030) for mitigating or adapting to climate change. After accounting for emissions reductions via INDCs from 147 parties in late October (nearly all parties have since submitted), the UN Framework Convention on Climate Change (UNFCCC) estimated global greenhouse gas (GHG) emissions in 2030 to be 56.7 gigatonnes (billion tonnes) of carbon dioxide equivalent (Gt-CO2eq). The International Energy Agency (IEA) estimated 41.9 Gt-CO2eq (from energy use and industrial processes of more than 150 countries). Compared to the pre-INDC scenario, the UNFCCC estimated that global emissions would decrease by 5.9 per cent in 2030.
But how much closer would we be to limiting emissions in order to confine global average temperature increase to 2°C above pre-industrial levels? Under a least-cost 2°C mitigation scenario, the UNFCCC analysis suggests that global GHG emissions should be 41.6 Gt-CO2eq in 2030. The global emissions gap (comparing INDCs against a 2°C pathway) in 2030 is 15.1Gt-CO2eq. Under the IEA "bridge scenario", the gap is 6.1 Gt-CO2eq (because only energy and industrial processes are estimated). These ranges reflect different assumptions of emissions peaking, technology curves and economic growth rates. That said, all models show that, despite the positive impact of the INDCs, a big shortfall in global effort remains.
The going gets tougher in the post-Paris world. Governments agreed to limit warming to well below 2°C and pursue efforts to limit it to 1.5°C. However, there is scanty evidence of the technological pathways that can deliver the higher ambition. The fifth assessment report of the Intergovernmental Panel on Climate Change explicitly mentions that there is little literature available for atmospheric emissions concentration pathways below those consistent with 2°C. Researchers working on integrated assessment models must now explore the pathways to 1.5°C, potential technology scenarios,and associated mitigation costs.
It is clear that the limited carbon space is going to shrink even more rapidly if we aimed for 1.5°C. For a 66 per cent probability of staying within 2°C, the world's emissions budget between 2011 and 2100 is 1000Gt-CO2. Our analysis finds that, under their INDCs, the cumulative emissions during 2011-2030 from China, the EU and the US would be 218, 68 and 96 Gt-CO2, respectively. With a target of 2°C, we find that, between 2011 and 2030, these three regions would together corner at least 38 per cent of the world's total permissible emissions up to 2100. With a revised aspiration of 1.5°C, the world's remaining carbon space shrinks to 550 Gt-CO2 (with just 50 per cent probability) and to merely 400 Gt-CO2 (with 66 per cent probability). In short, under current policies, by 2030 China, the EU and the US will eat up 95 per cent of the whole world's nearly century-long carbon space.
What are the implications? First, after 2030 emission mitigation needed to stay within 1.5°C or even 2°C will be more stringent. Even with the INDCs, cumulative global carbon dioxide emissions by 2030 will overshoot permissible limits. India might be doing more than its fair share but the biggest emitters will have to significantly increase their ambitions. Moreover, low-income regions like Africa will become key to the post-2030 mitigation agenda, needing effective emissions trading mechanisms and technology transfer regimes.
Secondly, negative emission technologies will become increasingly important. CEEW's modelling suggests that global carbon dioxide emissions under a 2°C pathway would need to peak in 2030 at 36 Gt-CO2; and even earlier if 1.5°C were pursued. Furthermore, emissions would have to be negated from later this century, say with as yet unproven technologies such as bio-energy carbon capture and storage technology. If CCS were removed from the portfolio of choices, energy systems would find it challenging to deliver deep mitigation after 2050.
Thirdly, there is already growing evidence of climate change impacts. Research by CEEW, IIM-Ahmedabad and IIT-Gandhinagar finds that 447 of India's districts are already experiencing temperature increases consistent with a more than 2°C trajectory, affecting 800 million Indians; of these 36 are on track for more than 4°C temperature rise. Climate change is going to hit us very hard and adaptation needs to be central in future climate discussions.
Finally, the economy of the 21st century will be built on advances in resource efficiency, decentralisation and greater empowerment of the consumer. Even as we fight for principles of fairness and justice, India's primary national interest (for national development and national security) will be to invest in the economy of the future. The world has come together to sign a historic climate agreement. But this is just the start. For a few degrees more (or less), the fate of millions will be determined in the coming decades.
Arunabha Ghosh is the chief executive and Dr Vaibhav Chaturvedi is research fellow at Council on Energy, Enviroment and Water (http://ceew.in).
Twitter: @GhoshArunabha
Disclaimer: These are personal views of the writer. They do not necessarily reflect the opinion of www.business-standard.com or the Business Standard newspaper
