Portfolio alignment metrics: what are they and how are they used in net zero investing?

Limits to Paris compatibility of CO2 capture and utilization

Net-zero emissions chemical industry in a world of limited resources

The Paris Agreement's central aim is to strengthen the global response to the threat of climate change by keeping the global temperature rise during this century well below 2°C above preindustrial levels and to pursue efforts to further limit the temperature increase to less than 1.5°C above the preindustrial levels. China has already signed the Paris Agreement, and its action plays a vital role in determining the outcome of the Agreement. As the largest developing country, it accounted for 26% of total global greenhouse gas (GHG) emissions in 2016. China's emissions grew very rapidly during the reform period of the past 40 years. If China does not comply with the Agreement, then it is hard for the world to achieve the goals it has set for itself. But it is by no means an easy task for China. Although the aggregate size of GHG emissions already dominate the global picture, China's per capita emissions are still significantly below the levels of many developed and developing countries. It would be difficult to convince the Chinese public that China should cut emissions aggressively, especially if this comes with a significant economic cost. As some Chinese commentators put it: since all the advanced countries had their GHG emissions during their early stages of economic development, why should China now be stripped of the right to develop its economy? So the question is if deep cuts to GHG emissions would be harmful for the Chinese economy. In their paper (Jiang et al., 2021), Jiang and his research team provide an excellent analytical foundation for thinking about the issues of GHG emission cuts, not only for the public, but also for policymakers. By building a quantitative model, Jiang et al. are able to derive numerical results on the likely impact on the macroeconomy, industrial structure, and the composition of energy. The most important finding, in my view, is that achievement of the “2°C” goal could actually result in China's gross domestic product (GDP) in 2050 being 1.5% higher, and consumption being 1.7% higher, compared with the baseline scenario. Indeed, this is very encouraging. Of course, the efforts trying to achieve the “2°C” goal could force a lot of structural changes in the Chinese economy. But these structural changes could make the overall economy more efficient, while bringing about new investment at the same time. The common perception that deep cuts to GHG emissions will mean a loss for China is simply wrong. By significantly reducing GHG emissions, China not only contributes to the global environment, but also improves its own economy. With this empirical judgment, Jiang and his colleagues should be more effective in convincing their bosses at the National Development and Reform Commission (NDRC) and the State Council to set a more ambitious target of peaking of CO2 emissions earlier – it is not only doable, but also beneficial. In fact, the Chinese economy is already in the middle of important structural changes in favor of GHG emission reduction. The share of the manufacturing sector in the overall economy peaked in 2012 and the weight of the service sector is rising quickly. Such changes and other efforts trying to improve efficiency could make the “2°C” goal or even the “1.5°C” goal more attainable. However, these results do not imply that implementation of deep cuts to GHG emissions will be painless. As Jiang et al. (2021) demonstrate, important adjustments will have to take place in order to achieve the policy goal, including changing the composition of energy supply, raising the share of electrification and upgrading technology in the transportation sector. Some industrial sectors, such as the steel, cement and chemical industries, could experience major changes. Therefore, success or failure of the “deep cut” policy depends not only on the government's determination, but also, more importantly, on policy skills to smooth the transition process. This calls for policy measures to help workers, factories, and regions that are affected by the transition process. This will be a key test for the Chinese government, including Jiang and his colleagues at the NDRC.

Approaches for a low-carbon production of building materials: A review

The Paris Agreement stipulates that global warming be stabilized at well below 2 °C above pre-industrial levels, with aims to further constrain this warming to 1.5 °C. However, it also calls for reducing net anthropogenic greenhouse gas (GHG) emissions to zero during the second half of this century. Here, we use a reduced-form integrated assessment model to examine the consistency between temperature- and emission-based targets. We find that net zero GHG emissions are not necessarily required to remain below 1.5 °C or 2 °C, assuming either target can be achieved without overshoot. With overshoot, however, the emissions goal is consistent with the temperature targets, and substantial negative emissions are associated with reducing warming after it peaks. Temperature targets are put at risk by late achievement of emissions goals and the use of some GHG emission metrics. Refinement of Paris Agreement emissions goals should include a focus on net zero CO2—not GHG—emissions, achieved early in the second half of the century. While well-known for its temperature targets, the Paris Agreement also aims for net zero GHG emissions. IAM results reveal net zero GHG emissions are not always required to meet the temperature targets, and that net zero CO2 emissions are a more suitable aim.

Cutting through the noise on negative emissions

<p>With the adoption of the Paris Agreement in 2015 the world has decided that warming should be kept well below 2°C while pursuing a limit of 1.5°C above preindustrial levels. The Paris Agreement also sets a net emissions reduction goal: in the second half of the century, the balance of global anthropogenic greenhouse gas emissions and removals should become net zero. Since 2018, in response to the publication of the IPCC Special Report on Global Warming of 1.5°C, a flurry of net zero target announcements has ensued. Many countries, cities, regions, companies, or other organisations have come forward with targets to reach net zero, or become carbon or climate neutral. These labels describe a wide variety of targets, and rarely detailed. Lack of transparency renders it impossible to understand their ultimate contribution towards the global goal. Here we present a set of key criteria that high-quality net zero targets should address. These nine criteria cover emissions, removals, timing, fairness and a long-term vision. Unless net zero targets provide clarity on these nine criteria, we may not know until it is too late whether the collective promise of net zero targets is adequate to meet the global goal of the Paris Agreement.</p>

Background: Climate change is predicted to be our century's most significant health threat. In 2021, 46 countries committed to environmentally sustainable low carbon health care systems. Of those, 34 were from low- and middle-income countries (LMICs). Currently, health systems are responsible for 4.4% of global greenhouse gas (GHG) emissions, with health systems in high-income countries (HICs) contributing the largest proportion to the sector's GHG emissions. However, future increases are predicted in LMICs in the absence of robust GHG mitigation. This systematic review aims to identify evidence-based GHG mitigation interventions to guide the transformation of health care systems towards net zero, specifically in LMICs. Additionally, potential synergies between interventions that aid adaption to climate change and mitigate GHG emissions will be investigated. Methods: This protocol will follow the 'Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) checklist of recommended items to address in a systematic review protocol'. A comprehensive search will be conducted on electronic databases identified as relevant. Search terms were identified to capture all relevant peer-reviewed, primary research published between 1990 and 2022. The risk of bias will be assessed, and the quality of evidence graded. The eventual narrative synthesis will feed into a theory of change framework on GHG mitigation of health care systems in LMICs. Discussion: This systematic review will synthesise the existing evidence around GHG mitigation interventions across all scopes of emissions, including scope 1 (health care operations), scope 2 (energy), and scope 3 (supply chains). It can be used to inform recommendations on how health care systems in LMICs can reduce emissions while prioritising which actions to take to gain the most significant reductions in GHG emissions, considering ease of implementation, scope and cost. Finally, this can catalyse further research in this area which is urgently needed.

Background: Climate change is predicted to be our century's most significant health threat. In 2021, 46 countries committed to environmentally sustainable low carbon health care systems. Of those, 34 were from low- and middle-income countries (LMICs). Currently, health systems are responsible for 4.4% of global greenhouse gas (GHG) emissions, with health systems in high-income countries (HICs) contributing the largest proportion to the sector's GHG emissions. However, future increases are predicted in LMICs in the absence of robust GHG mitigation. This systematic review aims to identify evidence-based GHG mitigation interventions to guide the transformation of health care systems towards net zero, specifically in LMICs. Additionally, potential synergies between interventions that aid adaption to climate change and mitigate GHG emissions will be investigated. Methods: This protocol will follow the 'Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) checklist of recommended items to address in a systematic review protocol'. A comprehensive search will be conducted on electronic databases identified as relevant. Search terms were identified to capture all relevant peer-reviewed, primary research published between 1990 and 2022. The risk of bias will be assessed, and the quality of evidence graded. The eventual narrative synthesis will feed into a theory of change framework on GHG mitigation of health care systems in LMICs. Discussion: This systematic review will synthesise the existing evidence around GHG mitigation interventions across all scopes of emissions, including scope 1 (health care operations), scope 2 (energy), and scope 3 (supply chains). It can be used to inform recommendations on how health care systems in LMICs can reduce emissions while prioritising which actions to take to gain the most significant reductions in GHG emissions, considering ease of implementation, scope and cost. Finally, this can catalyse further research in this area which is urgently needed.

The 71st LCA forum was held on 18 June 2019 in Zurich, Switzerland, to discuss the current status and future plans of environmental benchmarking for buildings in view of the 1.5 °C target stipulated in the Paris Agreement. The Paris Agreement requires a significant reduction in greenhouse gas emissions, in fact net zero by 2050. One of the priority areas is the building stock, as it is an important source of greenhouse gas emissions. COP23, the International Energy Agency (IEA) and an increasing number of countries are extending their consideration from aspects such as energy consumption and emissions from building operation to the manufacture of construction materials and building construction. The event offered an excellent platform to exchange ideas and thoughts on existing and planned environmental benchmarking schemes for buildings. The one day event dealt at first with life cycle assessment (LCA) approaches applied in European, Asian, Australasian and American countries to assess the environmental performance of buildings. Within a round robin test, organised within the IEA EBC (Energy in Building and Communities) Annex 72 project, 22 organisations from 21 countries assessed the environmental performance of one identical building, the be2226 office building located in Lustenau, Austria. The materials, the building technologies and the energy consumption were kept constant. This allowed to identify the main differences in LCA data used and LCA methodology applied in the national contexts. In the LCA forum, eight organisations presented the current state or future plans of an environmental benchmarking system in their home country. The systems were characterised in terms of scope, in particular (a) which types of buildings are covered; (b) which life cycle stages are included; (c) which building elements and which operational energy uses are considered; and (d) which environmental impacts are addressed. Furthermore, the default reference service life and the main source of LCA data were specified and the current or planned benchmark values for greenhouse gas emissions of residential buildings were reported. The round robin test revealed the LCA background data as one major source of difference in assessment results. Methodological and modelling choices were less important except for the Danish assessment, which applies a comparatively long reference study period (80 years for office buildings, 120 years for residential buildings) and considering future changes in the electricity mix towards 100% renewables to describe the operational electricity demand during the lifetime of the building. Most benchmarking systems presented are applied on new and retrofit residential, office and school buildings. Other use types such as shops, restaurants, universities or hospitals are covered only in few or just one country. The greenhouse gas emission benchmark for residential buildings (construction and operation) revealed a significant gap between the current level of the building benchmarks on one hand and the target of net zero CO2-eq emissions derived from the 1.5 °C scenarios of IPCC on the other. An online inquiry carried out among the audience during the event showed a preference for a per capita overall budget of 500 kg CO2-eq per year to derive greenhouse gas emission benchmarks for buildings and that life cycle-based benchmarks for buildings should be legally binding. The 71st LCA forum on environmental benchmarks for buildings showed that the experts present acknowledge the net zero CO2 emission target derived from the 1.5 °C scenarios. Several countries have expertise and experience in assessing the environmental impacts of buildings. However, the current (mostly voluntary) benchmarking schemes are way too weak to support the building sector in contributing significantly to the required CO2 emission turn off. The outlook given by several speakers showed that the current benchmarks will likely be tightened and oriented on the planetary boundaries and on the scientifically defined CO2 emission budgets rather than on the technical or economic feasibility. Finally, the responsibility of governments for defining environmental requirements and targets was stressed. The event, the exchange of ideas and the discussions helped to nurture and hopefully accelerate the developments in the construction sector of the home countries of the experts and government representatives. These developments will contribute to a society whose environmental impacts remain within the carrying capacity of our planet.

Major US electric utility climate pledges have the potential to collectively reduce power sector emissions by one-third

The Paris Agreement for a post-2020 international framework for tackling climate change was adopted in December 2015. The agreement requires that each country prepares and communicates nationally determined contributions (NDCs) every 5 years, including greenhouse gas (GHG) emission reduction targets. Most countries submitted NDCs before the Paris Agreement. According to our analyses using a global energy and GHG emission reduction assessment model, the emission reduction costs of the NDCs vary widely among countries; and those differences will induce carbon leakage, thus the expected global emission reduction is smaller than that predicted by simply aggregating the emission reductions of all the countries. Moreover, the emissions are larger than those required for the pathways leading to a high probability of temperature stabilization at below 2 °C above pre-industrial levels. To fill the gap, a rigorous review process employing robust indicators measuring emission reduction efforts is crucial. However, the development and deployment of innovative technologies with cheaper costs is even more significant.

Signatories to the Paris Agreement have pledged to keep global warming to well below 2 °C above pre-industrial levels and preferably below 1.5 °C above pre-industrial levels. Beyond over-shooting Paris Agreement warming levels followed by net negative emissions, achieving a state of net zero carbon dioxide emissions is required to satisfy Paris Agreement warming goals. Research on climate changes under net zero CO2 emissions is very limited to date with no comprehensive analysis of changes in extremes. In this study, we use results from Earth System Models in the zero emissions commitment model intercomparison project to understand regional mean-state climate change patterns during a 100 year period following carbon dioxide emissions cessation. We also perform an initial study of the evolution of hot and cold monthly temperature extremes after net zero CO2 emissions, including an assessment of how the change in frequency of temperature extremes affects areas of different levels of socioeconomic development based on regional Human Development Index (HDI). The results show that most land regions experience a fast and continuous cooling response following emissions cessation, with large areas of significant model agreement. In contrast, the Southern Ocean continues warming over the century after emissions cessation. The frequency of land-based local monthly high temperature extremes generally stays constant or decreases during the century after emissions cessation, however, decreases in heat extreme frequencies are generally less for locations with lower modern HDI than areas with higher HDI which suggests that inequality of climate change will remain an issue even after net zero CO2 emissions. There is an evident emergence of local monthly cold extremes following emissions cessation with most significant impact over high HDI mid- and high-latitude land regions.

Abstract. To track progress towards keeping global warming well below 2 ∘C or even 1.5 ∘C, as agreed in the Paris Agreement, comprehensive up-to-date and reliable information on anthropogenic emissions and removals of greenhouse gas (GHG) emissions is required. Here we compile a new synthetic dataset on anthropogenic GHG emissions for 1970–2018 with a fast-track extension to 2019. Our dataset is global in coverage and includes CO2 emissions, CH4 emissions, N2O emissions, as well as those from fluorinated gases (F-gases: HFCs, PFCs, SF6, NF3) and provides country and sector details. We build this dataset from the version 6 release of the Emissions Database for Global Atmospheric Research (EDGAR v6) and three bookkeeping models for CO2 emissions from land use, land-use change, and forestry (LULUCF). We assess the uncertainties of global greenhouse gases at the 90 % confidence interval (5th–95th percentile range) by combining statistical analysis and comparisons of global emissions inventories and top-down atmospheric measurements with an expert judgement informed by the relevant scientific literature. We identify important data gaps for F-gas emissions. The agreement between our bottom-up inventory estimates and top-down atmospheric-based emissions estimates is relatively close for some F-gas species (∼ 10 % or less), but estimates can differ by an order of magnitude or more for others. Our aggregated F-gas estimate is about 10 % lower than top-down estimates in recent years. However, emissions from excluded F-gas species such as chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs) are cumulatively larger than the sum of the reported species. Using global warming potential values with a 100-year time horizon from the Sixth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC), global GHG emissions in 2018 amounted to 58 ± 6.1 GtCO2 eq. consisting of CO2 from fossil fuel combustion and industry (FFI) 38 ± 3.0 GtCO2, CO2-LULUCF 5.7 ± 4.0 GtCO2, CH4 10 ± 3.1 GtCO2 eq., N2O 2.6 ± 1.6 GtCO2 eq., and F-gases 1.3 ± 0.40 GtCO2 eq. Initial estimates suggest further growth of 1.3 GtCO2 eq. in GHG emissions to reach 59 ± 6.6 GtCO2 eq. by 2019. Our analysis of global trends in anthropogenic GHG emissions over the past 5 decades (1970–2018) highlights a pattern of varied but sustained emissions growth. There is high confidence that global anthropogenic GHG emissions have increased every decade, and emissions growth has been persistent across the different (groups of) gases. There is also high confidence that global anthropogenic GHG emissions levels were higher in 2009–2018 than in any previous decade and that GHG emissions levels grew throughout the most recent decade. While the average annual GHG emissions growth rate slowed between 2009 and 2018 (1.2 % yr−1) compared to 2000–2009 (2.4 % yr−1), the absolute increase in average annual GHG emissions by decade was never larger than between 2000–2009 and 2009–2018. Our analysis further reveals that there are no global sectors that show sustained reductions in GHG emissions. There are a number of countries that have reduced GHG emissions over the past decade, but these reductions are comparatively modest and outgrown by much larger emissions growth in some developing countries such as China, India, and Indonesia. There is a need to further develop independent, robust, and timely emissions estimates across all gases. As such, tracking progress in climate policy requires substantial investments in independent GHG emissions accounting and monitoring as well as in national and international statistical infrastructures. The data associated with this article (Minx et al., 2021) can be found at https://doi.org/10.5281/zenodo.5566761.

Responsible for 37% of global greenhouse gas (GHG) emissions, the construction and operation of buildings involves substantial potential to mitigate climate change. Although they represent only a small part of the building stock, publicly-owned buildings can lead by example and stimulate emission reductions through public procurement processes that are aligned with existing climate goals. In this paper, possible GHG emission reduction pathways for public office buildings in Austria are explored. A building stock model for Austria’s publicly-owned office buildings is developed, which projects operational and embodied GHG emissions from new construction, renovation and demolition until 2050. Findings show that phasing out fossil fuel use in building operations by 2050 enables GHG emission pathways that are compatible with the Carbon Law but still exceed Austria’s available carbon budget for public office buildings. A higher renovation rate can facilitate the fossil fuel phase-out by reducing energy demand. Embodied GHG emissions are becoming increasingly important and the main source of GHG emissions when phasing out fossil fuels in space heating. More research and policies are therefore needed to accelerate reductions of embodied GHG emissions towards net zero.