The Royal Society of the United Kingdom releases 12 major scientific and technological issues on carbon neutrality

Recently, the Royal Society of the United Kingdom released a series of briefings, proposing 12 scientific and technological issues to accelerate the achievement of net zero greenhouse gas emissions and improve the ability to respond to climate change[1]. This work organized and coordinated the participation of more than 120 experts from different disciplines in more than 20 countries, and outlined the research and development deployment priorities for achieving net zero emissions by 2050 in 12 technical fields, providing reference for government decision-making. Details are as follows:

1. Next generation climate models

The establishment of a system for modeling the Earth's climate is one of the great scientific achievements of the past half century. Recent studies have shown that a new generation of high-resolution models can significantly improve the quality of information related to climate mitigation and adaptation, covering everything from global and regional climate impacts to extreme weather and severe climate change risks. An international next-generation climate modeling center based on an exascale computing and data facility should be established through international cooperation to achieve a leap in resolution and computing power to fully understand the global impacts of climate change at the kilometer scale to support net zero technology roadmaps and investments in climate adaptation. Through partnerships and collaboration with this facility, national climate modeling and services around the world will reach a new level. To ensure the adoption and use of the latest predictions, the facility could also include dedicated operational data services using the latest digital technologies in data analysis and information science, such as artificial intelligence, machine learning, and advanced visualization. Sustainable development can be promoted through an "incubator" to inspire new ideas for next-generation modeling, and public-private cooperation can be promoted on cutting-edge digital solutions based on data clouds and application programming interfaces through an "open data lab" to train developers and users of climate model information.

2. Carbon Cycle

At present, humans have a good understanding of the Earth's carbon cycle. For example, land and oceans absorb more than half of the carbon emissions from human activities as carbon sinks, but there is no guarantee that such a large absorption will continue. Therefore, further understanding is needed to determine whether carbon sinks can continue to store carbon dioxide (CO2) at historical levels. The future of carbon sinks will depend on the level of CO2 in the atmosphere and how fast it rises or falls, the impact of climate change, and possible direct human intervention. Protecting carbon sinks, especially forests, is essential to maintaining their function. Climate change is expected to have the greatest and most uncertain impact in a high-carbon emission future. Enhancing natural carbon sinks through human intervention is essential to achieving net zero emissions, including sustainable afforestation, reforestation, agricultural soil management, and peatland restoration. Research to improve the understanding of the carbon cycle should include: continuous observation and monitoring of the atmosphere, land, and ocean through in situ and satellite data; better understanding of the potential instability of carbon sinks, and the development of models that more comprehensively characterize the complexity of the carbon cycle.

3. Digital technology

Based on large amounts of data, computational science has the potential to create “digital twins” that simulate and optimize multiple economic sectors, significantly reducing carbon emissions by 2030. Digital technologies can play an important role in the low-carbon transition by achieving emissions reductions in the global economy and limiting emissions caused by computing itself. In particular, there is an opportunity to bring together governments, academia, industry, etc. to create a “digital twin earth” or “earth operation control loop” and feed real-world operation data back into the model for iterative updates, by simulating, optimizing and changing economic activities to minimize emissions and improve efficiency. “Net zero computing” can play an important role in global, regional and national net zero strategies. The electricity consumption and carbon footprint of digital technology sectors, including embodied emissions, should be proportional to their benefits. Strengthening global coordination on data standards, quality and regulation will enable the reliable collection, sharing and use of relevant data to better quantify greenhouse gas emissions and support applications that reduce emissions. At the same time, “digital twins” of natural and economic systems can be created at the city, region, country and even global levels to minimize emissions, provide decision-making information and promote sustainable development, and can also help governments explore the impact of “what-if” scenarios and interventions. Global collaboration is essential to establish a trusted governance framework for computing and data infrastructure for net-zero systems. The technology industry should lead by example, with technology companies publicly reporting their energy use and direct and indirect emissions, and optimizing the use of renewable energy. The global research and innovation ecosystem needs to be improved to support relevant technological advances, and to take advantage of free or low-cost "digital commons" platforms driven by governments.

4. Future battery energy storage solutions

In a future net-zero world, low-carbon transportation and stable electricity supply require more powerful, longer-lasting, and faster-charging batteries. Sustainable future batteries also require the use of abundant materials and zero-carbon manufacturing processes. Batteries are the most efficient way to store renewable electricity, but current technological advances are not yet suitable for large-scale energy storage. Lithium-ion batteries are the most viable battery energy storage technology in the short term, and related research focuses on increasing energy density, reducing costs, extending life, improving charging safety and speed, and recycling and reuse of batteries. In the long term, researchers are exploring next-generation batteries using other materials and technologies to achieve more widespread and economical electrification. International cooperation and coordination should focus on identifying and experimenting with new resource-abundant materials to reduce costs, expand battery use, and minimize the environmental impact of battery production. If enough attention is paid, completely new batteries with lower costs and higher energy density will be developed in the future.

5. Low-carbon heating and cooling

Heating and cooling account for 40% of energy-related carbon emissions, and low-carbon heating and cooling technologies in residential, commercial and industrial settings are at different stages of development and deployment is slow. Emissions need to be reduced by improving energy efficiency, applying clean technologies to replace fossil fuels for heating and cooling, and innovating in thermal energy storage and transportation. Different countries need a range of approaches to reduce carbon emissions from heating and cooling, but there is room for greater international cooperation and networking. Reducing the energy consumption of heating and cooling buildings through improved insulation, heat reflection and other means is a top priority for any decarbonization plan. Compared with fossil energy-related technologies, many low-carbon heating and cooling technologies are still in their infancy and require large-scale demonstration and deployment to test their cost-effectiveness. Key areas of research, development and deployment of low-carbon heating and cooling include: heat pumps, electric heaters, district systems, renewable energy heating and hydrogen.

6. Meeting the net zero challenge with hydrogen and ammonia

Hydrogen and ammonia have important potential roles in a net-zero economy. Both fuels are versatile and can be produced and used in a variety of ways. They can be produced from renewable energy and applied in hard-to-decarbonize sectors such as heavy transport, industry and heating, and can be used as a medium for energy storage and transportation. Currently, hydrogen and ammonia are already widely used in industry and agriculture, but their production has a high greenhouse gas footprint. Significant greenhouse gas emissions can be reduced by decarbonizing existing technologies and new ones. Both fuels face technical challenges, including in production, storage and use, especially the cost of achieving net-zero lifecycle emissions. Further research, development, demonstration and deployment are needed to identify areas where hydrogen and ammonia can have a significant impact in practice. Demonstration of hydrogen and ammonia should be prioritized in sectors such as heavy industry and heavy vehicles, rail and shipping, and energy storage, where they have great potential to become cost-effective low-carbon alternatives. Large-scale demonstrations through clusters of industrial partners are most cost-effective, often in port areas, especially when integrated with offshore wind power. International cooperation, including infrastructure cooperation, can help expand deployment based on current pilot projects and should be combined with research to promote further innovation.

7. Carbon capture and storage (CCS)

CCS is essential to achieving net zero emissions in economies that use fossil fuels or release carbon in any way. Studies show that most possible net zero emission routes require CCS to achieve. CCS is a proven technology option for decarbonizing the power and industrial sectors. For hard-to-decarbonize sectors such as heavy industry, CCS may be the last line of defense to reduce carbon emissions. CCS has been proven at global industrial scale and is a reliable, safe and auditable method of storing carbon for at least 10,000 years. However, the current pace of CCS construction is too slow to meet the required scale. Global carbon capture capacity is about 40 million tons of CO2/year, of which only 25% is stored geologically to mitigate climate change, and accelerated deployment is needed to accelerate cost reductions and scale up the technology. As experience in CCS deployment accumulates, establishing clusters with multiple carbon capture sites and transporting CO2 to shared storage sites through shared pipelines or transportation is a way to share and reduce unit costs. Such CCS projects are currently under construction and planning. Research into new capture technologies has the potential to reduce costs in the future, but it may take decades to commercialize. CO2 removal technologies, including negative emissions technologies such as direct air carbon capture with carbon storage (DACCS), can help achieve the widely agreed net-zero emissions goal by mid-century. Individual countries or groups could encourage CCS technology development through subsidies or carbon taxes. Alternatively, in order to reliably store enough carbon, carbon suppliers may be required to assume storage obligations.