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Topic

Decarbonisation

Topic Brief

Decarbonisation

Greenhouse gas emissions in 2023 were the largest in history: humanity released 35.8 gigatonnes of carbon dioxide (GtCO₂). However, this is just 0.1 per cent more than 2022, raising hopes that emissions are peaking.2

The major emissions sources are:

Energy supply: 34% Industry: 24% Agriculture, forestry and other land use: 22% Transport: 15% Buildings: 6%.

In 2023, levels of atmospheric CO₂ reached 419 parts per million, about 50 per cent higher than pre-industrial levels.3 As a result, Earth has warmed 1.18°C above the 20th-century average.4 There is now an 80 per cent chance that the annual global temperature will be more than 1.5°C above pre-industrial levels for at least one year between 2024 and 2028.5 To give a 50 per cent chance of limiting global warming to 1.5°C, we can emit no more than 275 GtCO₂: at 2023 rates, we will use up this carbon budget in seven years.6

In the 2015 Paris Agreement, governments agreed to hold “the increase in the global average temperature to well below 2°C above pre-industrial levels” and pursue efforts “to limit the temperature increase to 1.5°C above pre-industrial levels.”7 Existing policies are insufficient and are likely to lead to 2.5°C of heating by the end of the century.8 However, current policies and pledges represent a significant advance on the position 10 or 20 years ago. It may be that we will soon hit tipping points where first pledges, and then policies, are sufficient to achieve the 2°C target. A number of science and technology-based strategies exist that will assist in achieving this goal.

KEY TAKEAWAYS

Decarbonising the global economy presents a significant technical and sociopolitical challenge. To limit warming to 1.5°C or 2°C, global emissions must peak by 2025 and fall rapidly. To achieve 1.5°C, net global emissions must fall 43 per cent from 2019 levels by 2030 and 84 per cent by 2050.1 Renewable energy such as solar and wind has a significant part to play and is rapidly becoming cheaper. There are also considerable opportunities in reducing energy demand, particularly from buildings, transport and certain industries. However, there are some hard-to-abate emissions, notably from agriculture and from certain forms of manufacturing such as steelmaking: reducing these emissions requires the development and/or scaling of new technologies. Finally, there are a number of negative emissions technologies (NETs) that can remove carbon dioxide from the air. These may prove useful later in the century but their scale is too small to offer a substitute for rapid emissions cuts.

The drive to reduce the amount of CO₂ in the atmosphere has been a global priority for a number of decades. Moving away from polluting fossil fuels has been a major focus of this effort, which is why energy transition was judged to have low anticipatory need. Despite being rated very highly for its transformational impact, the field has already received plenty of attention and is expected to reach maturity over relatively short timescales. In contrast, large-scale deployment of negative emission technologies is almost two decades away and has received less attention so far, suggesting a greater need for foresight in this area.

Anticipatory Impact:

Three fundamental questions guide GESDA’s mission and drive its work: Who are we, as humans? How can we all live together? How can we ensure the well-being of humankind and the sustainable future of our planet? We asked researchers from the field to anticipate what impact future breakthroughs could have on each of these dimensions. This wheel summarises their opinions when considering each of these questions, with a higher score indicating high anticipated impact, and vice versa.

Anticipated impact on who we are as humans
Anticipated impact on how we will all live together
Anticipated impact on the well-being of humankind and sustainable future of our planet

SubField

Renewable energy

In 2022, about one-seventh of our overall energy came from renewables.9 This represents rapid growth: as recently as 2010, solar and wind were just 1.7 per cent of global energy.

Future Horizons:

×××

5-yearhorizon

Solar overtakes coal in electricity production

Cost and efficiency improvements mean that solar becomes a larger global source of electricity than coal. Improvements in battery technology allow short-term storage of energy from renewables, but intermittency remains a problem. Algorithmic innovations improve control of supply and demand in electricity markets, freeing more renewable energy to create green hydrogen. Small-scale laboratory fusion successes in privately-funded companies stimulate further investment in research. Improved stabilisation enables wind turbines to be built further offshore in deeper waters.

10-yearhorizon

Energy storage innovations grow renewable market share

Half of global electricity comes from renewable sources. Seasonal and long-term energy storage, such as power-to-gas, flow batteries and liquefied hydrogen and air, becomes a commercially viable output of wind and solar energy sources. Shipping begins to decarbonise, using hydrogen and in some cases, experimental sail-based propulsion. Accelerating cost declines, due to factors such as falling steel prices and an increase in offshore wind turbine installations, further decarbonising many countries’ energy production and use.

25-yearhorizon

Fusion investments begin to pay off

Small-scale, pilot nuclear fusion plants begin to come online. Electrical grid interconnectors span all of Eurasia. Significant improvements in the energy efficiency of synthetic fuel manufacture enable its use for zero-carbon aviation and shipping.

Much of this growth is due to rapidly falling costs. Solar and wind are now routinely cheaper than fossil fuels.11 This has occurred despite ongoing government subsidies of fossil fuels, which may become indefensible as battery technology improves and undermines the argument that fossil fuel-based generating capacity is necessary for when there is no wind or sunshine. A number of promising developments in materials science offer hope of increased efficiency for photovoltaics.12

There has been considerable disagreement about the role that can be played by hydrogen.13 In theory, hydrogen produced by renewable energy (“green hydrogen”) is entirely renewable. In practice, the high demand for renewable electricity means that there tends to be little left over for hydrogen production. Hydrogen may have a relatively limited role to play as “blue hydrogen”, generated as a by-product of fossil fuel combustion. Though it will not be a zero-carbon fuel until carbon capture can be achieved at commercial scales, blue hydrogen could nonetheless help mitigate “hard-to-abate” emissions. Related “Power to X” technologies, such as synthetic fuels made using renewable electricity, are promising, but face efficiency challenges.

Nuclear fission and fusion may also have roles to play. Small-scale nuclear fission reactors are also under development, although their chances of commercial success remain difficult to predict.14 Commercial-scale fusion plants are still probably decades away.15

Renewable energy - Anticipation Scores

The Anticipation Potential of a research field is determined by the capacity for impactful action in the present, considering possible future transformative breakthroughs in a field over a 25-year outlook. A field with a high Anticipation Potential, therefore, combines the potential range of future transformative possibilities engendered by a research area with a wide field of opportunities for action in the present. We asked researchers in the field to anticipate:

The uncertainty related to future science breakthroughs in the field
The transformative effect anticipated breakthroughs may have on research and society
The scope for action in the present in relation to anticipated breakthroughs.

This chart represents a summary of their responses to each of these elements, which when combined, provide the Anticipation Potential for the topic. See methodology for more information.

SubField

Hard-to-abate emissions

A significant fraction of our carbon emissions comes from hard-to-abate sources such as aviation, industry, agriculture and forestry. Part of the solution will be on the demand side:16 diets that feature less red meat will cut emissions, as will reducing food waste and better cultivated meat. There are also improvements to be made on farms, for instance in soil management, selective cattle breeding for low methane production17 and anaerobic manure processing.18

Future Horizons:

×××

5-yearhorizon

Innovation slows the growth of emissions

An appetite for climate change mitigation in agriculture creates a rapid cycle of innovation that slows the growth of emissions. Government programmes begin to support decarbonisation of heavy industry.

10-yearhorizon

Bioprocessing cuts food waste emissions

Innovations in bioprocessing mean that global emissions from food waste are half those of 2023. Cultivated meat protein becomes widely available, but cannot satisfy the rising global demand for meat.

25-yearhorizon

Industrial processes achieve significant carbon emission reduction

Steel and cement manufacture are close to carbon neutral, thanks to progress in chemical research that generates cleaner industrial processes. 25 per cent of people adopt vegetarian diets. Low- or zero-carbon aviation fuels become available.

In steel manufacture, carbon is typically used to transform iron ore into iron, but newer “direct reduction” processes use hydrogen.19 There is potential to use “oxyfuel” — air with most of the nitrogen removed —to create emissions that are easier to capture. This may help cut emissions from cement production.20

Research on sustainable aviation fuels is progressing slowly because powered flight requires fuels with a high energy-to-mass ratio — batteries can certainly not yet match kerosene. Solar-powered planes remain small. Some companies are experimenting with replacing fractions of their jet fuel with biofuels or chemically-engineered synthetic fuels, but these initiatives are not market-ready.21

Hard-to-abate emissions - Anticipation Scores

The uncertainty related to future science breakthroughs in the field
The transformative effect anticipated breakthroughs may have on research and society
The scope for action in the present in relation to anticipated breakthroughs.

This chart represents a summary of their responses to each of these elements, which when combined, provide the Anticipation Potential for the topic. See methodology for more information.

SubField

Energy demand

Reducing demand for energy can have a significant effect on carbon emissions. There is huge scope for demand reduction: for example, the UK could cut its energy demand by more than half by 2050.22 The International Energy Agency (IEA) estimates that intensive efforts towards increased energy efficiency could cause global energy demand to fall by 8 per cent by 2050, even if the economy more than doubled in size and the population grew by 2 billion.23

Future Horizons:

×××

5-yearhorizon

Electric cars begin to dominate the new car market

Electric cars become cheaper than petrol in most developed countries, and innovations in battery technology make them more practical to use. Developments in grid technology enables stored energy in electric car batteries to be sold into national electricity grids when demand is high.

10-yearhorizon

Building standards assist decarbonisation goals

Reforms to building standards and other regulations promote lower energy demand and renewable installation. World steel demand peaks, creating a significant reduction in industrial energy use. Sustainable fuels begin to be available as “drop-in” solutions, helping to abate emissions from heavy transportation.

25-yearhorizon

Global energy demand has peaked

Heat pump innovations, combined with smart meters and building regulations mean that new buildings in most developed countries use minimal energy and are net suppliers of energy. Massive expansion of high-speed rail reduces demand for cars and aviation. Global energy demand is 8 per cent smaller than today but serving an economy twice the size. Electric cars outsell petrol cars globally. New low-temperature industrial processes reduce the energy demand of heavy industries.

Operation of buildings, which consumes 30 per cent of the energy generated globally, is ripe for innovation.24 For example, a large fraction of that energy is used for temperature control. Improved construction and design, combined with the use of technologies such as ground-source heat pumps, can virtually eliminate this need.

There is also great scope to reduce energy demand through greater use of public transport and improvements to industrial processes.25 New designs of cars and skyscrapers are reducing the amount of steel and concrete needed, for instance. Improvements to recycling systems, and the gradual transition to a circular economy, also reduce the need for manufacture of new materials.26

Energy demand - Anticipation Scores

The uncertainty related to future science breakthroughs in the field
The transformative effect anticipated breakthroughs may have on research and society
The scope for action in the present in relation to anticipated breakthroughs.

This chart represents a summary of their responses to each of these elements, which when combined, provide the Anticipation Potential for the topic. See methodology for more information.

SubField

Negative emissions technologies

An important element in decarbonisation is negative emissions technologies (NETs). These are technologies for drawing greenhouse gases out of the air and permanently storing them. To limit global heating to 1.5°C, it is estimated that we will need to remove around 810 GtCO₂ between now and 2100 – equivalent to 15 years of 2017 greenhouse gas emissions.27 Most scenarios for achieving net-zero emissions, and for limiting global heating to 1.5°C or 2°C, include the future effect of NETs that are predicted to mature later this century.

Future Horizons:

×××

5-yearhorizon

Research innovation assists carbon capture and use technologies

Investment in new direct air capture (DAC) technologies re-invigorates academic research in the field. AI-based chemical innovations begin to find applications for re- purposing captured carbon. Advances in DAC technology, combined with rising carbon pricing, spur further investment in research.

10-yearhorizon

NETs begin to scale

Testing of ocean liming and iron fertilisation gives indications of whether these projects have potential. The first large scale BECCS (bioenergy with carbon capture and storage) project begins. Construction materials that include captured carbon become commonplace.

25-yearhorizon

Carbon capture becomes a widely-used technology

DAC is implemented on a large scale. AI helps to find new uses for captured carbon. Long-term storage solutions are agreed and implemented.

Some NETs are Natural Climate Solutions. Reforestation can be a NET, because trees take carbon dioxide from the air. Other natural climate solutions include restoring wetlands and kelp forests, which are also carbon sinks. Natural climate solutions could mop up at most 23.8 Gt GtCO₂ per year.28

Other NETs are highly artificial. Enhanced weathering entails crushing minerals into powder, which reacts with CO₂ and water to form a new mineral that can be used or buried. Lime can be thrown into the ocean to react with dissolved CO₂ to produce calcium carbonate that sinks to the seabed.

Direct Air Capture (DAC) uses machines that contain chemical “sponges”, which draw CO₂ out of the air. This CO₂ can be sequestrated in underground repositories such as aquifers or depleted oil and gas reservoirs. Alternatively, it can be converted into fuels, fertilisers or construction materials – though this does not necessarily reduce emissions.

All these technologies face problems of scale, cost and geopolitics, and all require certifications and proof of long-term reliability for the market to “trust” them.

Negative emissions technologies - Anticipation Scores

The uncertainty related to future science breakthroughs in the field
The transformative effect anticipated breakthroughs may have on research and society
The scope for action in the present in relation to anticipated breakthroughs.

This chart represents a summary of their responses to each of these elements, which when combined, provide the Anticipation Potential for the topic. See methodology for more information.

References

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