Climate Warming Mitigation from Nationally Determined Contributions

Individual countries are requested to submit nationally determined contributions(NDCs)to alleviate global warming in the Paris Agreement.However,the global climate effects and regional contributions are not explicitly considered in the countries’decision-making process.In this study,we evaluate the global temperature slowdown of the NDC scenario(ΔT=0.6°C)and attribute the global temperature slowdown to certain regions of the world with a compact earth system model.Considering reductions in CO_(2),CH_(4),N_(2)O,BC,and SO_(2),the R5OECD(the Organization for Economic Co-operation and Development in 1990)and R5ASIA(Asian countries)are the top two contributors to global warming mitigation,accounting for 39.3%and 36.8%,respectively.R5LAM(Latin America and the Caribbean)and R5MAF(the Middle East and Africa)followed behind,with contributions of 11.5%and 8.9%,respectively.The remaining 3.5%is attributed to R5REF(the Reforming Economies).Carbon Dioxide emission reduction is the decisive factor of regional contributions,but not the only one.Other greenhouse gases are also important,especially for R5MAF.The contribution of short-lived aerosols is small but significant,notably SO_(2)reduction in R5ASIA.We argue that additional species beyond CO_(2)need to be considered,including short-lived pollutants,when planning a route to mitigate climate change.It needs to be emphasized that there is still a gap to achieve the Paris Agreement 2-degree target with current NDC efforts,let alone the ambitious 1.5-degree target.All countries need to pursue stricter reduction policies for a more sustainable world.

Biomass residue to carbon dioxide removal:quantifying the global impact of biochar

The Climate Change Conference of Parties(COP)21 in December 2015 established Nationally Determined Contributions toward reduction of greenhouse gas emissions.In the years since COP21,it has become increasingly evident that carbon dioxide removal(CDR)technologies must be deployed immediately to stabilize concentration of atmospheric greenhouse gases and avoid major climate change impacts.Biochar is a carbon-rich material formed by high-temperature conversion of biomass under reduced oxygen conditions,and its production is one of few established CDR methods that can be deployed at a scale large enough to counteract effects of climate change within the next decade.Here we provide a generalized framework for quantifying the potential contribution biochar can make toward achieving national carbon emissions reduction goals,assuming use of only sustainably supplied biomass,i.e.,residues from existing agricultural,livestock,forestry and wastewater treatment operations.Our results illustrate the significant role biochar can play in world-wide CDR strategies,with carbon dioxide removal potential of 6.23±0.24%of total GHG emissions in the 155 countries covered based on 2020 data over a 100-year timeframe,and more than 10%of national emissions in 28 countries.Concentrated regions of high biochar carbon dioxide removal potential relative to national emissions were identified in South America,northwestern Africa and eastern Europe.

Uncertainty of temperature rise under nationally determined contributions and carbon neutral policies

Nationally determined contributions raised by Paris Agreement aim to control the temperature rise below 2°C or even 1.5°C at the end of the 21st century,compared to pre-industrial levels.However,the climate response of the Nationally Determined Contributions(NDCs)remains uncertain due to unstable policies and their credibility.In this study,we calculated the uncertainty of global temperature rise caused by uncertain NDCs and carbon-neutral policies and discussed the difficulty of policy implementation.The results show that there will be 8 GtC uncertainty in emission at the end of the 21st century,responsible for the temperature rise of 0.37°C(1.73–2.10°C).A delayed policy in emission reduction by major emitters would result in a temperature rise of over 2°C,while under non-delay policy,the 2°C target will be possibly achieved.Besides,low-emission countries would introduce a 30 GtC cumulative emission uncertainty at the end of the 21st century if there are no restrictions,leading to a 0.3°C global warming uncertainty.Developed countries need more substantial reductions in carbon intensity to achieve their climate policies while developing countries are under less pressure.The reduction of carbon intensity requires the strengthening of technical and economic methods.This study provides a reference for the realization of emission policies and temperature rise targets.

Modeling the implementation of NDCs and the scenarios below 2°C for the Belt and Road countries

In order to understand better on medium-and long-term climate change issues in international cooperation of the Belt and Road Initiative(BRI),this paper is meant to assess the implementation of National Determined Contributions(NDCs)of the BRI countries and the emission constraints under the Paris Agreement to hold the increase in the global average temperature to well below 2℃ above pre-industrial levels,based on the Belt and Road Integrated Assessment Model(BRIAM)and the best available data.The results show that the BRI countries are expected to collectively reduce about 3.2 billion tons of CO_(2)emissions with the implementation of their NDCs by 2030.In order to achieve the global goal of 2℃,without appropriate mitigation burden sharing and enhanced climate finance support,the BRI countries will face big challenges to bridge the emission gaps.The investment in clean energy and related new infrastructures in BRI will rise sharply to above US$100 trillion by the end of this century accordingly with the increase in carbon price,which will also eventually have a significant impact on the price of electricity and oversea freight transport in a connecting world.

Is the Paris rulebook sufficient for effective implementation of Paris Agreement?

Glasgow Climate Conference concluded the negotiation on implementing rules for Paris Agreement and adopted the Glasgow Climate Pact.Based on practices under the UNFCCC and its Kyoto Protocol,Paris Agreement enhanced global climate change governance.Paris Agreement established a system centered around‘nationally determined contributions’(NDCs)of Parties,with a transparency framework to ensure information flow running the system,meanwhile facilitating implementation by Parties through the mechanism on facilitation and compliance,as well as urging Parties to enhance ambition both at individual level and aggregate level through the mechanism on Global Stocktake.By doing so,it is logical that the system would lead to the achievement of the goal set by Paris Agreement.However,the system stil faces significant deficiency,such as lack of information timeliness,intransparency of some necessary information,hypothesis-based but not solution-based decision-making,and lack of effective assurance for developing countries to get finance and technology support.It is concluded that this system is beneficial to long-term climate change policy decision and tracking progress of actions,while for shor-term decision-making,more comprehensive consideration is needed than only based on the mechanisms of and outcomes from the system.International society should pay more attention to the progress of implementation,as well as ambition of various support provided to developing countries,than only the ambition of mitigation target numbers.

Renewable Energy： The Trillion Dollar Opportunity for Chinese Overseas Investment

This paper compares the global flows of Chinese overseas investment in power plants with renewable energy investment potential embodied in ＂Nationally Determined Contributions.＂ With over US$1tn （671 GW） in Nationally Determined Contributions renewable energy investment potential in developing countries, we estimate the total level of power plant investments from China＇s policy banks and commercial entities since the early 2000s at US$216bn （158 GW）. Although past investment has mainly been directed at fossil fuels and hydroelectric power, we argue that China is uniquely poised to lead renewable energy global investments for three reasons： （i） China＇s solar and wind industries are globally competitive; （ii） Chinese policy banks can give domestic firms advantages in financing global expansion; and （iii） renewable energy investment opportunities still exist in developing countries with less sovereign risk than for traditional energy investments. The Chinese government should provide special incentives for the policy banks to capitalize on these investment opportunities by deploying Chinese solar and wind technologies to Belt and Road countries and beyond.

Situation and measures of China＇s CO2 emission mitigation after the Paris Agreement

Global response to climate change has entered the phase of full implementation of the Paris Agreement. To control the global temperature rise below 2℃, all countries must make more efforts to reduce emission. China has combined its goal of emission reduction for combating climate change with its domestic sustainable development strategy to promote energy revolution and the transition of economic development to low-carbon pat- terns. Through reinforcing the commitment and action before 2020, the CO2 intensity of GDP can decrease by more than 50% by 2020 compared with that of 2005, and the external commitment target of a 40%-45% decrease can be over fulfilled. Currently, under the new economic normal, China further strengthens the policy measure, vigorously saves energy, enhances energy use efficiency and the economic output benefit, and simultaneously develops new and renewable energy and accelerates energy structural decarbonization, so that the annual decrease rate of the CO2 intensity of GDP keeps a high level of more than 4% and remains increasing. Thus, the decrease rate of the CO2 intensity of GDP will exceed the GDP growth rate, and then CO2 emission will peak around 2030. This will promote the fundamental turning of economic development mode, and lay a foundation for the establishment of a sustainable energy system with near- zero emissions and with new and renewable energy as the main body in the second half of this century. China implements the concept of green low-carbon development and accelerates the low carbon transition of energy and economy to achieve win-win results in economic growth and CO2 emission mitigation, and these policies and actions will also provide experiences for many other developing countries. On the other hand, China will continue to play a positive and constructive leading role in the implementation of the Paris Agreement internationally, and promote the construction of new mechanisms of win- win cooperation, fairness and justice and common development for global climate governance. Moreover, China will make an effort to build a community of common destiny for mankind, promote pragmatic coopera- tion among countries, especially among developing countries, and take combating climate change as a new development opportunity for jointly moving toward climate-friendly low-carbon economic development path.