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Climate Change Targets:
The Role of Nuclear Energy» The world’s effort to decarbonise is one of the defining challenges for this generation and the windowfor action is rapidly narrowing» Nuclear energy is playing an important role today and can do more to help meet decarbonisation targets» Continued operation of the existing fleet, as well as new builds of large-scale and small modular
reactors could avoid 87 gigatonnes of cumulative emissions between 2020 and 2050

» By 2050, nuclear energy could displace 5 gigatonnes of emissions per year, which is more than what
the entire US economy emits annually today» Energy policymakers have an important role to play to create the enabling conditions for success
The world is not on track to meet thedecarbonisation objectives of the Paris Agreement
As highlighted by the IPCC synthesis report (IPCC, 2018), theworld is not on track. Rather than the steep reductions scientists
had hoped for, global emissions are expected to rise by 16% by2030. The window for action is rapidly narrowing. Even if carbon
emissions were to remain constant, the entire carbon budgetwould be consumed within eight years.
Constrained by the world’s carbon budget, carbon emissions
must peak within the next few years and drop to zero by 2100
(or sooner). This will require policy changes around the world aswell as massive investments in innovation, infrastructure, and thedeployment of non-emitting energy resources. More specifically,electricity grids must be decarbonised; vehicle fleets must beelectrified or transitioned to non-emitting fuels; and a range ofindustrial sectors (e.g. off-grid mining, buildings, chemicals, ironand steel, cement) must be transformed as well.
Current emissions are on a trajectory to far exceed the targets
arising from the 1.5° scenario. It is clear that a major shift indirection will be required if countries are to meet their objectives.

The IPCC 1.5°C scenario foresees, on average,
1 160 GW of operational nuclear energy by2050, a three-fold increase compared to 2020
The 444 nuclear power reactors in operation worldwide today
provide 394 gigawatts of electrical capacity that supplies
approximately 10% of the world’s electricity. Nuclear energy© OECD 2021

is the largest source of non-emitting electricity generation inOECD countries and the second largest source worldwide (afterhydropower). There are approximately 50 more nuclear reactors
under construction to provide an additional 55 gigawatts ofcapacity and more than 100 additional reactors are planned.
Existing nuclear capacity displaces 1.6 gigatonnes of carbon
dioxide emissions annually and has displaced 66 gigatonnesof carbon dioxide since 1971 – the equivalent of two years ofglobal emissions (NEA, 2020).
The nuclear sector can support future climate change mitigation
efforts in a variety of ways. Existing global installed nuclear
capacity is already playing a role and long-term operation of theexisting fleet can continue making a contribution for decades tocome. There is also significant potential for large scale nuclear
new builds to provide non-emitting electricity in existing andembarking nuclear power jurisdictions, and, in particular, replacecoal. In addition, a wave of near-term and medium-term nuclear
innovations have the potential to open up new opportunities
with advanced and small modular reactors (SMRs), as wellas nuclear hybrid energy systems, reaching into new markets
and applications. These innovations include sector coupling,combined heat and power (cogeneration) for heavy industry andresource extraction, hydrogen and synthetic fuel production,desalination, and off-grid applications.
In a special report published in 2018 (IPCC, 2018), the IPCC
considered 90 pathways consistent with a 1.5°C scenario– i.e. pathways with emissions reductions sufficient to limit
average global warming to less than 1.5°C. The IPCC foundthat, on average, the pathways for the 1.5°C scenario requirenuclear energy to reach 1 160 gigawatts of electricity by 2050,
up from 394 gigawatts in 2020.

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100

Installed capacity (GWe)

1 400

9080

1 20070

1 00060800

5040600

30

400

20200

102020

2025

2030

2035

2040

2045

2050

0

Cumulative CO2 emissions avoided (GtCO2)

Figure 1: Full potential of nuclear contributions to net-zero
Cumulative emissions avoided
IPCC 1.5°C scenarios (2050 average) = 1 160 GW nuclear
capacity (based on the average of IPCC 1.5°C scenarios)
Ambitious projections
Small modular reactors (post-2035 market extrapolation)
Large-scale new builds (planned)Long-term operation (to 80 years)
Conservative projections
Small modular reactors (2035 market outlook)
Large-scale new builds (under construction)
Long-term operation (planned)

Source: NEA, Forthcoming.

Nuclear energy can displace 87 gigatonnes ofcumulative emissions between 2020 and 2050
1 160 GW by 2050 is an ambitious target for nuclear energy, but
it is not beyond reach. It can be achieved through a combinationof long-term operations, large-scale new builds and small
modular reactors, as shown in Figure 1.
New analysis by the NEA identifies the potential contributionof nuclear energy to clean energy capacity and emissions
reductions between 2020 and 2050, taking into consideration
the potential contributions from power and non-power
applications of nuclear technologies (NEA, forthcoming).
Taken together, the contributions of long-term operation, largescale new builds using existing nuclear technologies, small
modular reactors, nuclear hybrid energy and hydrogen systems
begin to reveal the full extent of the potential for nuclear energy
and nuclear innovations to play a significant and growing role inpathways to net-zero by 2050.

Table 1. Projected contributions of nuclear energy
to cumulative emissions reductions (2020-2050)

Additionally, there are key enabling conditions for successthat the nuclear sector and energy policymakers more broadly
should address in the areas of system costs, project timelines,
public confidence and clean energy financing.
A systems approach is required to understand the full costs ofelectricity provision, and to ensure that markets value desired
outcomes: low-carbon baseload, dispatchability, and reliability.
Rapid build-out of new nuclear power is possible, but requires aclear vision and plan. Historical and recent experience show that
under the right policy frameworks and a robust programmatic
approach, nuclear power can be a low-carbon technology with
rapid delivery times. This was the case historically for countries
such as France and jurisdictions such as Ontario in Canada thathave both decarbonised their electricity mix in less than twodecades with nuclear energy and hydropower. Today, the Barakah
project in the United Arab Emirates demonstrates that such arate of deployment can be achieved even with existing nuclear
reactor designs. In China and Korea, countries in more advanced
stages of nuclear construction learning, construction lead-time
for large existing nuclear reactor designs with increased safety
are, on average, around 5-6 years – or even faster.

* All cumulative emissions from 2020 to 2050 are shown in gigatonnes ofcarbon dioxide (GtCO2).

Building and maintaining public confidence is essential for
all nuclear energy projects, from mining to research anddevelopment, operations, and waste management. Building
trust is central to building public confidence and requires
sustained investments in open and transparent engagement
as well as science communication. A common mistake,however, is to assume that public confidence is primarily acommunications issue, when in actuality, public confidence
is much more complex, touching on issues of trust, values,
culture, and benefits sharing, among others.

Reaching the target of 1 160 gigawatts electrical capacity would
avoid 87 gigatonnes of cumulative emissions between 2020
and 2050. By 2050, nuclear energy could displace 5 gigatonnesof emissions per year, which is more than what the entire US
economy emits annually today.

Governments have a role to play in all capital intensive
infrastructure projects – including but not limited to nuclear
energy projects. This role can include direct funding, but also byenabling policy frameworks that allow an efficient allocation ofrisks. Nuclear energy projects can then compete on their merits
on an equal footing with other non-emitting energy projects.

Addressing the challenges faced by nuclear energy

Further reading

While the potential exists for nuclear energy to play a muchlarger role in global climate change mitigation efforts, nuclear
energy faces many challenges. The above estimates are notforecasts but represent what could be achieved with timely
enabling decisions.

IPCC (2018), Global Warming of 1.5°C, IPCC, Geneva, www.
ipcc.ch/sr15.

To seize the window of opportunity, the nuclear sector mustmove quickly to demonstrate and deploy near-term and mediumterm innovations including advanced and small modular reactors,
as well as nuclear hybrid energy systems using hydrogen.

NEA (2020), Unlocking Reductions in the Construction
Costs of Nuclear A Practical Guide for Stakeholders, OECD
Publishing, Paris, w w w.oecd - nea.org / jcms/pl _ 3 0 6 5 3 /unlocking-reductions-in-the-construction-costs-of-nuclear.

Cumulative emissions* avoided from…

…electricity…heat…hydrogenTotals…long term operation

38.3

6.7

4.3

49.2

…new builds of large Generation III reactors

16.2

4.2

2.4

22.8

…small modular reactors (SMRs)

9.7

3.6

1.8

15.1

Totals

64.1

14.5

8.5

87.1

© OECD 2021

NEA (forthcoming), Meeting Climate Change Targets: Projecting
the Potential Role of Nuclear Energy, OECD Publishing, Paris.

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