Super pollutants - Institute For Governance & Sustainable Development

The transition away from the production and consumption of high global warming potential (GWP) hydrofluorocarbons (HFCs) under the 2016 Kigali Amendment to the Montreal Protocol on Substances that Deplete the Ozone Layer has prompted air conditioning, refrigeration, and heat pump equipment manufacturers to seek alternative refrigerants with lower direct climate impacts. Additional factors affecting alternative refrigerant choice include safety (i.e., flammability and toxicity), environmental, and thermodynamic constraints. At the same time, manufacturers are incentivized to seek refrigerants with higher energy efficiency, which saves on electricity costs and reduces indirect greenhouse gas emissions from electricity generation. The life cycle climate performance (LCCP) metric is commonly used to assess the combined direct and indirect climate impacts of refrigerant-use equipment. Here, we consider an additional impact on climate performance: the degradation of refrigerant in equipment, i.e., the direct climate impacts of high-GWP byproducts that can form as the result of adding trifluoroiodomethane (CF3I) to refrigerant blends to reduce flammability. Such a production of high-GWP gases could change the acceptability of CF3I-containing refrigerants. Further, it highlights the need to understand refrigerant degradation within equipment in calculations of the environmental acceptability of new cooling technology.

Each year, one-third of the total food for human consumption is either lost or wasted even as millions worldwide experience food insecurity. Similarly, over 25 percent of vaccines are wasted each year while millions die from vaccine-preventable illnesses Sustainable cold chain infrastructure can significantly reduce post-harvest food loss and vaccine wastage and deliver social and climate benefits. However, acknowledging the need for cold storage alone does not ensure food security or access to vaccines, and must be supported by policies and resources, including technologies. Cooperation among G20 countries on cold chains can help coordinate the policies and resources necessary to advance food security, public health, and climate change mitigation.

Multilateral approaches to nitrogen pollution are generating synergies between climate change and food security and presenting opportunities to reduce nitrous oxide (N2O) globally. N2O is the most abundant ozone-depleting substance not yet regulated by the Montreal Protocol and a powerful greenhouse gas. Failure to reduce emissions will delay ozone layer recovery and worsen the climate crisis. While cost-effective mitigation technologies to reduce N2O emissions are available, policies and incentives to encourage the uptake of such measures are lacking. The G20, whose membership includes the world’s largest food exporters and fertilizer consumers, is positioned to advance N2O mitigation by supporting coordinated multilateral action. G20 leadership on N2O can support food security by preventing drastic impacts of climate change on food production and safeguarding the ozone layer, which protects agriculture and biodiversity from harmful ultraviolet B radiation. It can also support the achievement of countries’ net-zero climate goals and nationally determined contributions.

Heating and cooling demand for space conditioning and refrigeration accounts for around a fifth of global final energy consumption. Climate change, urbanization, and economic development have tripled electricity demand for cooling alone since the 1990s, with the majority coming from the use of inefficient cooling equipment, which burdens electricity grids, especially during peak hours. It is imperative to address the energy required to provide cooling. The Kigali Amendment to the Montreal Protocol addresses these needs by setting ambitious global targets to phase down refrigerants with high global warming potential while improving energy efficiency. Integrating energy efficiency and the refrigerant transition will contribute to economic security, well-being, energy access and security, and sustainability among the G20 countries.

Cities are responsible for over 70 percent of global greenhouse gas emissions and 75 percent of primary energy consumption. By 2050, over two-thirds of the world population will live in cities, resulting in even greater infrastructure needs and increased carbon emissions. Yet, cities largely remain on the sidelines in the design of national and international green transition policies. Cities can combine policy, practice, and participation by leveraging innovation, technology, and partnerships while transforming local governance models. There is a need for the G20 leaders to recognize and support the role of cities in accelerating climate action toward net zero and limiting warming to 1.5 °C. This Policy Brief suggests policy recommendations informed by current trends, Urban20 (U20) engagement group priorities, and previous communications by G20 countries to address the barriers that cities face in implementing effective climate action towards net zero. These recommendations emphasize on themes around empowering cities; building technical, institutional, and financial capacities of cities; facilitating climate finance; and enabling multi-stakeholder participation for achieving integrated urban climate action.

This paper recalls and documents the military leadership under the Montreal Protocol, presents indicative case studies of how technical performance of military systems was maintained or improved by adopting newer technologies and summarizes key lessons from military leadership in protecting the ozone layer. In addition to collaboration on technology development and demonstration, between 1991 and 2009, military organizations from various countries came together to conduct seven workshops specifically to review military ODS uses, share experiences with alternatives, and compare policy approaches to extract and share best practices. Lessons such as this can be applied to developing and adopting technologies that displace the need to emit greenhouse gas while improving the performance of military systems and reducing operating costs.

The agriculture and food system sector is a significant emitter of greenhouse gases (GHGs), primarily methane – associated with livestock and rice production – and nitrous oxide – most directly associated with nitrogen fertilizers, animal manure, and biological nitrogen fixation. There is, however, potential for agriculture to contribute to climate change mitigation. By leveraging the natural role of plants and soils in the cycling of organic carbon, agricultural land can act as a carbon sink through interventions for carbon sequestration like conservation agriculture. Studies estimate a technical potential of soils in global cropland and pasture land to store 2–5 Gt CO2 per year.

PxD and IGSD are partnering on an initiative to collaboratively identify opportunities for innovation in climate change mitigation, particularly for the greenhouse gases most problematic in agricultural production, methane and nitrous oxide, as well as carbon dioxide. This initiative includes four analytical pieces on the opportunities for climate change mitigation by smallholder famers, starting with carbon dioxide sequestration through enhanced rock weathering. Enhanced rock, or silicate, weathering (ERW) is a developing technology which leverages natural mineral weathering to draw carbon from the atmosphere.

The analysis found ERW’s potential for permanent carbon drawdown and agricultural co-benefits makes it an attractive mitigation strategy, particularly in equator and near-equator geographies like the Global South, where there are ideal soil pH, temperature, and moisture conditions for the technology. However, because ERW is a new technology that is still being tested and has yet to be studied in Global South contexts, there remain critical uncertainties around its safety, carbon sequestration potential, probable benefits to farmers, and feasibility. All of these factors must be addressed in order to move the technology forward.

Nitrous oxide (N2O) is both an ozone-depleting substance that damages the stratospheric ozone layer and one of the most potent greenhouse gases (GHGs) contributing to global climate change. As with almost all GHG emissions linked to anthropogenic processes, N2O emissions have increased significantly in recent decades. Agriculture is the main driver for these increases,11 with up to 71% of the increase in emissions from the 1980s to 2007-2016 coming from direct agricultural emissions. In particular, scientists have pointed to the use of nitrogen fertilizer as a key reason for the increasing N2 O atmospheric burden. Most smallholder farmers rely on their own judgment or blanket nitrogen fertilizer recommendations, which can miss critical variations in soil and crop nitrogen needs. Offering farmers in the Global South an accessible and user-friendly way to use nitrogen more efficiently will thus not only help reduce the environmental impact of the use of nitrogen fertilizer in agriculture but also improve farmers’ productivity and profits. Addressing the precision nutrient management gap for smallholder farmers in the Global South is a critical priority for achieving both anti-poverty and climate change goals, especially as the use of nitrogen fertilizer in Global South countries rises in coming years to meet increasing global food demands.

Burning trees for energy delivers a one-two punch against climate change mitigation efforts. Harvesting woody biomass reduces the sequestration potential of forest carbon sinks, while the combustion of woody biomass releases large quantities of carbon into the air. Forest regrowth may not offset these emissions for many decades —well beyond the time the world has left to slow warming to avoid catastrophic impacts from climate change. With little time left to achieve a sustainable and inclusive future, burning forests for energy contributes to warming in the near-term and is not a viable climate solution

This article begins with an overview of the scientific background of why harvesting and burning forests for energy is not a viable solution to climate change or related challenges. This background section includes an explanation of key terminology used in the article. The next section presents the European Union (EU)’s Renewable Energy Directive as a case study on the consequences of including bioenergy in renewable energy policies. Following the case study, the article examines bioenergy policies in the United States and China—the world’s two largest greenhouse gas emitters. The article concludes with policy recommendations to focus government action towards reducing reliance on energy from forest biomass. These recommendations are that governments: (1) re-evaluate their bioenergy policies and ensure lifecycle accounting of forest bioenergy’s climate emissions associated with harvesting and burning forest biomass; (2) end incentives for harvesting forests for fuel and invest in forest preservation, low-emission energy, and low energy demand pathways; and (3) advance international consensus on the harms from forest bioenergy, specifically the impact on climate and biodiversity.

Trifluoroiodomethane as a Precursor to High Global Warming Potential Climate Pollutants: Could the Transformation of Climatically Benign CF3I into Potent Greenhouse Gases Significantly Increase Refrigerant-Related Greenhouse Gas Emissions?