Dedicated climate ministries help to reduce carbon emissions

Abstract

Several countries have introduced dedicated national climate ministries in the last two decades. However, we know little about the consequences of these ministries. We demonstrate that the introduction of climate ministries helps to reduce carbon emissions. A difference-in-differences analysis of a global sample of countries reveals robust and statistically significant evidence that introducing a dedicated climate ministry lowers carbon emissions substantially. At the same time, establishing such climate ministries does not significantly influence the introduction of new climate policies. This indicates that climate ministries primarily amplify climate action by improving the effectiveness of the governmental measures taken rather than by increasing the number of climate policies themselves.

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npj | climate action Article
https://doi.org/10.1038/s44168-024-00147-9
Dedicated climate ministries help to
reduce carbon emissions
Check for updates
Julian Limberg 1, Yves Steinebach 2&JacobNyrup 2
Several countries have introduced dedicated national climate ministries in the last two decades.
However, we know little about the consequences of these ministries. We demonstrate that the
introduction of climate ministries helps to reduce carbon emissions. A difference-in-differences
analysis of a global sample of countries reveals robust and statistically significant evidence that
introducing a dedicated climate ministry lowers carbon emissions substantially. At the same time,
establishing such climate ministries does not significantly influence the introduction of new climate
policies. This indicates that climate ministries primarily amplify climate action by improving the
effectiveness of the governmental measures taken rather than by increasing the number of climate
policies themselves.
To effectively combat escalating climate change, governments must take
decisive action to substantially reduce greenhouse gas emissions. In recent
times, the discourse has shifted from the question of how to achieve inter-
national cooperation to the question of how to design national public
institutions to foster climate actions1–7. Specifically, the role of establishing
dedicated climate ministries has risen to the forefront of this scholarly
debate8,9. Dedicated climate ministries are considered potential catalysts for
driving comprehensive and concerted efforts toward climate action. The
main argument is that climate ministries come with clearer responsibilities
and increased administrative resources dedicated to addressing the issue of
climate change.
Despite these supposed advantages of dedicated climate ministries,
empirical evidence regarding their actual impact on climate policy ambi-
tions and effectiveness remains scarce. We address this research gap by
examining a comprehensive sample of 169 countries over a span of two
decades (2000 to 2021). We use a difference-in-differences (DiD) design to
investigate whether establishing a dedicated climate ministry makes a dif-
ference in terms of the quantity, type, and effectiveness of climate policies.
We compare countries that have introduced a dedicated climate ministry to
those that have not. Our analysis reveals that the establishment of dedicated
climate ministries contributes to a reduction in carbon emissions. Yet, it
does not significantly influence the introduction of new climate policy
legislation. Instead, variations in carbon emissions appear to be driven
largely by the enhanced effectiveness in the implementation and enforce-
ment of existing climate policies.
The paper is structured as follows: First, we discuss the purported
advantages of climate ministries in addressing climate change. Next, we
conduct a comprehensive mapping of existing climate ministries and ana-
lyze the impact of their introduction on carbon emissions. Furthermore, we
assess the mechanisms that link the establishment of a dedicated climate
ministry with carbon emission reduction. Thereafter, we discuss our results.
The final chapter presents our research design and methodologies.
The benefits of dedicated climate ministries
Dedicated climate ministry come with two central benefits. The creation of a
dedicated climate ministry helps to ensure clear lines of responsibility5,10.
Moreover, the creation of a dedicated climate ministry guarantees that
specific administrative resources, in terms of both staff and budget, are
allocated to addressing climate change issues. These advantages can enhance
climate action through different mechanisms.
First, governments can leverage such specialized ministries to
reduce CO
2
emissions through policy formulation. This can be achieved
through the proliferation of more, stricter, or better “designed”policies.
A climate ministry crystallizes accountability, clearly delineating the
responsibility for initiating and steering climate actions. In government
structures without a dedicated climate ministry, climate-related policy
responsibilities are often spread across various ministries or depart-
ments, such as those dealing with energy, environment, or industry11.It
is thus often unclear who (exactly) needs to take the measures it needs to
tackle climate change. In addition, even though comprehensive climate
action still requires the collaborative effort of various government sec-
tors, a climate ministry can drive cross-ministerial coordination, com-
pelling other departments to take necessary steps12. Moreover, the
augmented administrative capacities that come with climate ministry
can empower governments to formulate more and “better”policies. As
emphasized by Fernández-i-Marín et al., the creation of well-designed
policies is not a straightforward task –it requires a substantial level of
administrative capacity13. The establishment of a climate ministry, with
its focused mandate and specialized workforce, can significantly con-
tribute to the development and execution of these policies.
1King’s College London, London, Great Britain. 2University of Oslo, Oslo, Norway. e-mail: yves.steinebach@stv.uio.no
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Second, climate ministries play a pivotal role in enhancing the
effectiveness of a country’s climate policy through better enforcement
and implementation practices. Climate ministers typically do not
implement policies directly but delegate this task to governmental
agencies or administrative bodies situated at different levels of
government14. A key insight from the policy implementation literature
is that during this process, things might not transpire as intended, since
other levels of government might, for various reasons, fail to take the
requisite action to render a policy effective. These reasons can include
conflicting priorities, lack of clear guidance or insufficient expertise,
political opposition, or challengesincoordinationandcommunication
across the multiple agencies involved15. Equipped with dedicated
workforces and financial resources, a climate ministry can monitor
various enforcement agencies to ensure they are executing policies as
intended and assist subordinate levels of government in adhering to
climate objectives. Steinebach, for instance, finds that clean air policies
are more effective in reducing air pollutant emissions when the
implementation process is overseen by a specialized central ministry16.
Figure 1summarizes these theoretical considerations.
Mapping dedicated climate ministries
Figure 2presents the number of countries with a dedicated climate ministry
over time. The first ministry portfolio carrying “climate”in the organiza-
tional title was the “Minister of Climate Change Issues”created in New
Zealand in 2005. Of the 38 countries that have introduced a climate ministry
at some point in time, 30 still had a ministry in 2021. Interestingly, in only
five countries, these ministries were solely responsible for climate matters. In
most instances, the portfolio of these climate-centric ministries was merged
with at least one other policy domain, typically either “environment”or
“energy”.
Looking at the geographical distribution of climate ministries
(Fig. 3), we can see that starting with Belgium and Denmark in 2007,
many European countries have introduced dedicated climate min-
istries in the last two decades. However, climate ministries are not
exclusively a Western phenomenon. Several countries in the “Global
South”suchasGabon,India,andPapuaNew Guinea have established
climate ministries as well (see also Fig. S1 in the Supplementary
Material).
Climate ministries and carbon emissions
In the next step, we conduct an econometric analysis to identify
whether the introduction of a dedicated climate ministry affects carbon
emissions. As detailed below in the method section, we use a difference-
in-differences design to look at changes in carbon emissions up to 5
years before and after establishing a dedicated climate ministry. We
then compare emission trajectories to countries that have not intro-
duced a climate ministry in the same period and use a matching
technique to only compare countries with similar covariate
trajectories17.
As shown in Fig. 4, our empirical results strongly support dedi-
cated climate ministries’emission-reduction potential. In the year after
the establishment of a ministry, emissions drop on average by more
than 0.36 metric tons per capita (95% confidence interval of −0.71 to
−0.04 metric tons per capita) compared to countries that have not
introduced a climate ministry. This effect is statistically significant at
the 5% level and increases further to around 1.06 metric tons per capita
(95% confidence interval of −1.87 to −0.29 metric tons per capita)
after 5 years. This effect not only proves to be statistically significant
but also quite substantial. The emission savings after 5 years equates to
roughly one-eighth (12.5 percent) of the average per capita emissions
in OECD countries. In other words, establishing a climate ministry
substantially reduces carbon emissions. In contrast, emission trajec-
tories do not differ between countries before the establishment of a
dedicated climate ministry. Thus, the parallel trend assumption holds,
i.e., the identified effects on carbon emissions are not a continuation of
diverging emission trajectories prior to the introduction of climate
ministries.
Fig. 1 | Theoretical considerations on the benefits of dedicated climate ministries. This figure summarizes the theoretical considerations tested in this paper.
Fig. 2 | Number of countries with a dedicated climate ministry. The figure presents
the number of countries with a dedicated climate ministry over time between 2000
and 2021.
https://doi.org/10.1038/s44168-024-00147-9 Article
npj Climate Action | (2024) 3:70 2

What are the mechanisms driving this emission reduction?
As discussed above, climate ministries can help governments to achieve
emission reductions in different ways. First, by formulating more, more
ambitious, and “better”climate policies. Second, by enhancing the enfor-
cement and application of existing climate policies.
To assess whether the establishment of climate ministries leads to
more climate policies, we take the total number of climate mitigation
policies from the Climate Policy Database18 and use the same econo-
metric difference-in-differences technique to estimate the effect of
dedicated climate ministries on climate policy outputs. The results show
no statistically significant differences between countries that have
introduced a dedicated climate ministry and those that have not
(Fig. 5, left panel). On av erage countries do not levy more clim ate policies
after establishing a ministry. Furthermore, there are no diverging trends
in climate policy-making prior to the establishment of a climate
ministry. Thus, the emission-reduction effect of establishing a climate
ministry cannot be explained by a simultaneous increase in policies.
Certainly, evaluating the influence of climate ministries on the overall
count of policies overlooks the distinctions in the various types of policies
that governments can use to address climate change. Governments have an
array of both “soft”and “hard”climate policy instruments at their
disposal19,20. Notably, regulatory and market-based instruments—particu-
larly carbon trading and taxes –are considered more ambitious measures in
climate policy21. However, we do not find a statistically significant effect of
climate ministries on these ambitious climate policies either (Fig. 5,middle
panel). On average, countries that established a climate ministry do not have
a statistically higher likelihood of introducing more ambitious regulatory or
market-based climate policies.
Furthermore, it might be the case that the establishment of a climate
ministry leads to better designed policies. Government might make use of a
more diverse range of climate policies to demand-tailor policies to tackle
climate issues. To test this, we look at the impact of the establishment of a
climate ministry on the average instrument diversity (AID) of climate
mitigation policies. This measure, as proposed by Fernández-i-Marín et al.,
measures the policy design quality based on the degree to which govern-
ments use different instruments and instruments combinations across the
various policy targets and sectors they address13. The underlying logic is that
a greater instrument diversity reflects a greater effort of the government to
find “tailor-made”solutions to the different policy problems they address.
We do not find a statistically significant effect of the establishment of a
climate ministry on instrument diversity (Fig. 5,rightpanel).
We run several additional models to check for the sensitivity of our data
and the accuracy of our model choice. First, we run our models without
using the matching algorithm (Fig. S5), by additionally matching on lea-
dership changes (Fig. S6) as well as on green party government participation
(Fig. S8), and by only looking at ministries where the climate minister is the
head of the ministry (Fig. S7). Findings are robust. Furthermore, instead of
running a difference-in-differences analysis, we test for the influence of
climate ministries on carbon emission in an ordinary time-series cross-
section-analysis (Table S1). In this analysis, the presence (or absence) of
climate ministries is quantified using a binary dummy variable. Again, our
analysis shows that having a climate ministry is a statistically significant and
robust predictor of bigger reductions in CO
2
. In the full model that includes
Fig. 3 | Countries that have established a dedicated climate ministry. The world map presents per country the year of the first establishment of a dedicated climate ministry.
Fig. 4 | Effect of establishing a dedicated climate ministries on CO
2
emissions.
The figure present the effect of establishing a dedicated climate Ministries on per
capita CO
2
emissions. The gray areas show the 95% confidence intervals.
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npj Climate Action | (2024) 3:70 3

various control variables and a lagged dependent variable, CO
2
emissions
per capita decrease by 0.16 metric tons more for each year a country has a
dedicated climate ministry.
In sum, these findings indicate that introducing a climate ministry does
neither lead to more nor to more ambitious or better-designed policies. This
renders the improved implementation and enforcement of existing climate
policies as the most plausible explanatory factors for the observed differ-
ences. The key argument here is that the clearer delineation of responsi-
bilities and the provision of extra administrative resources within these
ministries improve the government’s capacity to supervise the imple-
mentation authorities16.
We probe this argument in three additional analyses. First, we differ-
entiate between specialized and general ministries. We define general
ministries as those that focus on at least three additional issue areas next to
climatechange,whilemorespecialized ministries are defined as dealing with
a maximum of two additional issues. The heterogeneity of ministries’
portfolios should come at the cost of undermining the observed effects on
improved implementation as responsibility gets blurred and additional
(specialized) administrative resources are less plentiful8.Inlinewiththis
theoretical expectation, we do not find any effect of these ministries that deal
with climate as one of several topics on carbon emissions (Fig. S2 left panel).
In contrast, we do find a strong effect of establishing a more specialized
climate ministry (Fig. S2 right panel).
Second, we look at the effect of general environmental ministries on
carbon emissions. In contrast to climate ministries, environmental minis-
tries are not solely focused on climate action but typically deal with various
topics such as air pollution in general, water pollution and nature con-
servation. Using the same econometric technique, we find no robust sta-
tistically significant effect of establishing a general environmental ministry
on carbon emissions per capita (Fig. S3). This further supports the argument
that the specialization of dedicated climate ministries is key for reducing
carbon emissions.
Finally, we check whether the effect of having a climate ministry varies
between countries. In line with our arguments about the importance of
implementation effectiveness, we would expect that new climate ministries
are less likely to improve policy implementation in countries with lower
overall state capacity. In other words, a lack of general state capacity
undermines the effect of establishing new institutional structures. Over-
coming disjointed responsibilities and making sure additional resources are
usedforimplementationpurposesisharderwhenthestategenerallylacks
power and authority. This is well in line with previous research indicating
that general state capacity is a crucial determinant of a country’s capability to
build up more effective administrative structures to tackle climate change22.
We test for heterogenous treatment effects in two ways. First, we re-run
the previous analyses but leave out individual countrie stha t have established
a dedicated climate ministry. The effect of climate ministries on emission
after 5 years stays robust (Fig. S4). This ensures that our findings are not
driven by extraordinary emissionreductionsinspecific countries. The
analysis further indicates that the observed effect on CO
2
becomes markedly
stronger when excluding countries with particularly low state capacity, such
as India, Oman, Gambia, Zimbabwe, and Papua New Guinea. Given that
these states may encounter more significant challenges in establishing
effective administrative structures, despite potentially having the best
intentions, this finding reinforces our assertion that the creation of climate
ministries does indeed make a difference by enhancing administrative
capacities.
Second, we make use of the time-series cross-sectional analysis pre-
sented. This econometric set up allows us to conduct a statistical test which
checks whether the effect of having a climate ministry varies by overall state
capacity. To do this, we run a model with an interaction effect. More pre-
cisely, we use the full Model 4 in Table S1 and expand it by interacting the
climate dummy with generate a general state capacity index developed by
Hanson and Sigman23 who use Bayesian latent variable analysis covering a
wide range of indicators related to different state capacity dimensions. To
interpret the interaction effect, we present marginal effect plots24.Further-
more, we add a histogram to the plot and use a binning estimator developed
by Hainmueller et al.25. The estimator splits the data into three different bins
(high, medium, low) and estimates whether the effect of having a climate
ministry varies between the different bins. As shown in Fig. 6,ourresults
show that the effect of a climate ministry on carbon emissions is sub-
stantially stronger for countries with overall higher levels of state capacity. In
contrast, the effect is indistinguishable from zero in countries with lower
levels of state capacity. In sum, these findings show support for our argu-
ment about the crucial role of climate ministries in enhancing the effec-
tiveness of climate policy. In countries with substantive state capacity,
climate ministries help to lower emissions substantially, while lacking state
capacity undermines the mechanism of increased implementation effec-
tiveness fundamentally.
It is important to emphasize that our findings substantially dismiss
the notion that the observed impacts of climate ministries are merely a
“by-product”of an overarching rise in governmental climate ambitions.
If the creation of these ministries were simply a reflection of an under-
lying process of increased governmental commitment towards climate
action, we would expect to see ministry formation going hand in hand
with adopting more, or more ambitious, policies. Similarly, given the
absence of a trend before the creation of a climate ministry, we can rule
Fig. 5 | Effect of establishing a dedicated climate ministries on climate policies. The figure present the effect of establishing a dedicated climate ministries on the number of
the adopted policies; the number of ambitious adopted policies; and the average instrument diversity.
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npj Climate Action | (2024) 3:70 4

out the possibility that climate ministries are establ ished as a reaction to a
significant surge in climate policies. Instead, our evidence suggests that
climate ministries do have their own and tangible impact on policy
outcomes, independent of the broader (previous) governmental initia-
tives or ambitions.
Likewise, one might contend that the observed effects are not
attributable to enhanced enforcement, but rather to the signaling
effect of the state’scommitment.Forinstance,BayerandAklin
26 have
shown that the rollout of the EU Emissions Trading Scheme (ETS)
impacted businesses’behavior, even when carbon prices were
insufficiently high to drive tangible changes in carbon emission levels.
The authors conclude that the very establishment of a formal climate
policy framework was enough to bolster the perception of the gov-
ernment’s resolution among businesses, prompting them to begin
reducing their emissions. The same could be true for climate ministry
creation. Certainly, we cannot completely discount the possibility
that a portion of the emission reductions observed may stem from a
reaction by the targeted groups that is entirely disconnected from the
actual climate policies or their enforcement. Nevertheless, we con-
sider the argument for improved policy implementation to be more
compelling. This is for two reasons: First, if the impact were merely
attributable to “signaling,”then the specificity of the term “climate”
being used in isolation or in conjunction with other terms should not
yield a markedly different outcome (see again our discussion on the
level of “specialization”of climate ministries”). In both scenarios, the
signal sent by the government—its professed priority of addressing
climate concerns—is essentially the same. Second, if it were merely
about signaling, with the government failing to take substantive
action thereafter, we would expect to observe a more “abrupt”effect
that potentially fades as citizens and businesses come to realize that
the government’s intentions are not followed by concrete measures.
However, what we observe is quite the contrary; the impact steadily
grows stronger over time, suggesting that there is indeed “real”action
underpinning these changes.
Discussion
The challenging task of addressing climate change demands careful coor-
dination and a comprehensive transformation of existing institutional
arrangements. Our research into the establishment of dedicated climate
ministries offers important insights into the concrete ways in which insti-
tutional change can bolster climate action. Our empirical findings suggest
that creating designed climate ministries leads to significant reductions in
carbon emissions. This is pivotal, considering that a drop in carbon emis-
sions is a direct metric reflectingthetangibleimpactofclimatepolicies.This
positive outcome becomes even more noteworthy when we consider that
this reduction is achieved without a simultaneous increase in the number or
stringency of climate policies.
The presence of a dedicated climate ministry, as indicated by our
analysis, paves the way for a more coherent approach to climate action,
eliminating the potential pitfalls that arise from blurred or disjointed
responsibilities. By ensuring clear demarcation of responsibility and ded-
icating resources specifically towards climate policy issues, climate minis-
tries enhance the effectiveness of existing climate policies. This finding
refutes the notion that merely increasing policy numbers or intensifying
ambitiousness is the only path forward. Instead, it underscores the impor-
tance of having a dedicated body with clear responsibilities that can steer
climate action in a focused manner.
Yet, it is equally essential to recognize the limitations and nuances
within this broader observation. As revealed by our supplementary analyses,
mere nomenclature, or the cursory inclusion of “climate”within a ministry’s
name is not enough. The real impact comes from a genuine specialization,
where climate action is prioritized and not diluted amidst other responsi-
bilities. Our study also throws light on the significance of having the right
kind of institutional architecture. When climate action is situated within
broader (environmental) ministries, the specificity required for targeted
climate action could be compromised. Thus, while environmental concerns
are undoubtedly paramount, there is a pressing need for focused attention
on climate issues, given the scale and urgency of the climate crisis. In light of
the findings presented, two straightforward policy recommendations can be
made: First, governments should consider establishing stand-alone minis-
tries with a sole focus on climate change. Second, optimally, these should be
standalone climate ministries, free from the dilution of attention and
resources that often accompanies broader environmental or multi-focus
portfolios.
The formation of dedicated climate ministries and their impact on
carbon emissions presents a compelling argument, revealing the
importance of specialized institutional structures for effective climate
action5–7. However, the broader “ecosystem”within which these min-
istries operate is characterized by inter-ministerial dynamics and
coalition politics. Both these aspects can profoundly influence the
effectiveness of climate ministries in practice, and thus, merit closer
examination in future research. First, in any governmental structure,
ministries do not operate in isolation. Their actions, decisions, and
policy formulations often intersect with the mandates of other min-
istries. This intersection can either foster synergies or lead to compe-
tition for resources, policy dominance, or even bureaucratic turf
wars27,28 Future research could further investigate how the effectiveness
of climate ministries is influenced by the presence (or absence) of other
ministries. Second, the distribution of ministerial portfolios among
coalition partners is a strategic exercise, often reflecting the power
dynamics and priorities of the involved parties. It would therefore be
intriguing to explore how the influence of climate ministries varies, for
instance, based on whether the ministry is led by the senior or the
junior partner in a coalition. Finally, the effect of a climate ministry
might depend on broader socio-economic and political characteristics.
For example, our sensitivity analysis suggests that the effect of estab-
lishing a climate ministry might be stronger in richer countries with
Fig. 6 | Effect of establishing a dedicated climate ministries on climate policies for
different levels of state capacity. The figure present the effect of establishing a
dedicated climate Ministries on per capita CO
2
emissions for different levels of state
capacity. Its plots show the estimated marginal effects using both the conventional
linear interaction model and the binning estimator. The gray areas show the 95%
confidence intervals. The histogram shows the distribution of the moderator variable
by differentiating between countries with (red bars) and without (grey bars) a cli-
mate ministry in a respective year.
https://doi.org/10.1038/s44168-024-00147-9 Article
npj Climate Action | (2024) 3:70 5

higher overall administrative capacities. The rapid diffusion of climate
ministries will allow future analyses to have a closer look at factors that
might serve as moderators.
In conclusion, as countries grapple with the urgent task of climate
mitigation, creating dedicated climate ministries stands out as an ac tionable,
impactful step. Coupled with robust execution, these institutional changes
could become pivotal in the global battle against climate change.
Methods
Our analysis relies on panel data for 169 countries between 2000 and 2021,
and a list of countries can be found in the Supplemental Material. Our data is
structured in country-years. Our central independent variable is climate
ministry creation. We then look at the effect of establishing a dedicated
climate ministry on CO
2
emissionsaswellasonthenumber,type,and
design of policies.
We retrieved the ministry names (in English) and the dates of their
creation from the WhoGov dataset. Although the WhoGov dataset is pri-
marily designed to provide bibliographic details such as gender and party
affiliation of cabinet members across all countries, it can be restructured to
reveal the names of the organizations these cabinet members helm (Nyrup
& Bramwell 2020). A ministry’sportfoliocanbeidentified in two ways: first,
by dissecting the ministry’s structure to understand the subjects its orga-
nizational units handle and, second, by referring to the given name of the
ministry. Therefore, we code a country as having established a dedicated
climate ministry when the word “Climate”appears in a ministry name for
the first time. Moreover, we validated all the identified ministries against
secondary sources, and we checked whether there were any ministries not
identified by WhoGov by conducting systematic internet searches.
Although a ministry can hold responsibility for a specificpolicyareaeven
without its name explicitly referencing this area (for discussion, see Klüser,
et al.29), the inclusion of a policy area within a ministry’s name substantially
signifies its place within the ministry’s policy portfolio30.Thenamesof
ministerial portfolios and ministries are not always synonymous. For
example, in New Zealand, the minister for Climate Change operates in the
Ministry for the Environment. To take this into account we rerun the main
analysis in the Appendix (Fig. S7) where we exclude ministries with multiple
ministers.
Policy data were extracted from the Climate Policy Database18.Today,
this database includes over 5000 national climate policies worldwide. The
database conceives of policies as the combination of certain sectors (what is
addressed?) and policy types/instruments (how is it addressed?). The
included sectors encompass Agriculture and Forestry, Buildings, Electricity
and Heat, General, Industry, and Transport. The array of policy instruments
encompasses, among others, economic instruments, information and
education, regulatory instruments, and research & development and
deployment. We specifically distinguish between regulatory and market-
based instruments, typically viewed as more ambitious, and other policy
measures. The latter group includes initiatives related to information and
education, research & development and deployment, and voluntary
approaches. Data on CO
2
emissions comes from the World Bank, which
sourced data from the Climate Watch Historical GHG Emissions
Database31.
In our analysis, we also consider a range of different time-variant
variables to ensure a comprehensive examination of the relationships at
hand. These variables include the annual GDP growth rate per capita, which
provides a measure of the economic output per person. Data come from the
World Bank31. By incorporating this variable, we account for the economic
development of each country and its potential influence on the relationship
being studied32. Furthermore, we include the size of the industrial sector as a
share of GDP in our analysis to account for potential changes in economic
structure that could affect both the policy measures taken and the emissions
profile. A decrease in a country’s industry share may suggest both lower
emissions and a reduced level of political protectionism towards the
respective economic branches32. In addition, we account for a selection of
political factors. Previous research has shown that democracies exhibit
stronger commitments to mitigate climate change and are more inclined to
cooperate in international treaties33,34. Here, we use a binary variable that
measures whether a country was a democracy in a respective year to account
for democratization processes that might affect our result. The variable
codes a country as a democracy if it fulfills conditions for contestation and
participation35. In addition to these variables, we also account for climate
policies using the data from the Climate Policy Database when looking at
CO
2
emissions and vice versa, as both are likely to affect one another. By
including these control variables in our analysis, we aim to enhance the
robustness and accuracy of our findings by considering important economic
as well as political factors that may have an impact on the relationship under
scrutiny.
We use an econometric technique that leverages variation in the timing
of the establishment of dedicated climate ministries. In our models, we use
the approach by Imai et al. which combines matching methods with a
difference-in-differences estimator17.Wecomparecountriesthathave
established a dedicated climate year in a respective year with those countries
that have a similar pre-treatment trajectory in terms of treatment history
(i.e., whether a country has had a previous climate ministry that had been
closed again) and time-variant covariates. This allows us to look at the
development of the effect of establishing a climate ministry over time.
Formally, the average treatment effect on the treated takes the following
form:
δF;LðÞ¼EYi;tþFXit ¼1;Xi;t1¼0;P
L
‘¼2
Xi;t‘

Xit

¼1;

Xi;t1¼0Yi;tþFXit ¼0;Xi;t1¼0;P
L
‘¼2
Xi;t‘





Xit
¼1;Xi;t1¼0
ð1Þ
Parameter Fenables us to estimate the cumulative treatment effect over
time. Due to the time coverage of our data, we set F=5.Thus,wemeasure
the treatment effect of establishing a climate ministry for up to 5 years after.
Furthermore, we adjust for treatment history up to 5 years before the
introduction of a ministry by setting L¼5. Country ithat establishes a
ministry in year t is the treated unit. Put differently, Xit ¼1aswellas
Xi;t1¼0. For these countries, Yi;tþFXit ¼1;Xi;t1¼0;PL
‘¼2Xi;t‘

is the potential outcome. Since we cannot observe the counterfactual out-
come had a country not introduced a climate ministry, we look at the
potential outcome of those countries that have not introduced a climate
ministry in a respective year, namely:
Yi;tþFXit ¼0;Xi;t1¼0;Xi;t‘

L
‘¼2

jXit ¼0;Xi;t1¼0ð2Þ
As the introduction of climate ministries is not randomly assigned, we
have to account for observed as well as unobserved confounders
(PK
k¼1ðXkit Þ). To account for time-invariant confounders, we use a
difference-in-differences estimator that solely looks at changes in the
dependent variable. Furthermore, we use Mahalanobis matching to ensure
that we only compare countries that are similar on a set of time-varying
confounders. The difference-in-differences estimator accounts for unob-
served time-invariant confounders under the condition that the parallel
trend assumption holds. Only comparing units during the same time per-
iods and additionally accounting for GDP growth trajectories via the
matching approach also ensure that our results are not driven by common
economic chocks such as the 2007 to 2008 financial crisis.
Standard errors are computed by using the block-bootstrap procedure
introduced by Imai et al.17. In contrast to standard bootstrapping, this
procedure uses the weight each observation gets when matching and uses it
as a conditional factor instead of recomputing it in the bootstrapping
procedure.
https://doi.org/10.1038/s44168-024-00147-9 Article
npj Climate Action | (2024) 3:70 6

In addition to the difference-in-differences analysis, we also run a time-
series cross-sectional data analysiswithcarbonemissionspercapitain
metric tons as our dependent variable. Since we are interested in changes in
carbon emissions, we include country fixedeffectsinourmodels.Weusea
stepwise approach to ensure that our results are not driven by covariate
choices. We start by solely including the existence of a climate ministry each
year plus country fixed effects. Subsequently, we add year fixed effects, our
control variables, and lagged levels of CO
2
emissions. We use standard OLS
standard errors.
Data availability
All data used in this article are available upon request.
Received: 18 December 2023; Accepted: 22 July 2024;
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Acknowledgements
We would like to express our gratitude to the editors and anonymous
reviewers for their valuable suggestions on how to enhance our manuscript.
We also extend our thanksto the participantsof the Policy,Bureaucracy, and
Organization (PBO) workshop in Geilo, members of the Environmental
Politics and Governance (EPG) Group (online), and attendees of the
Research Colloquium at the Chair of Christoph Knill at the LMU Munich for
their feedback. This research was funded by the Norwegian Research
Council (ACCELZ Project, Grant No. 335073) and received Småforsk
funding from the Department of Political Science at the University of Oslo.
Author contributions
J.L., Y.S. and J.N. have made substantial contributions to the conception or
design of the work or the acquisition, analysis, or interpretation of the data;
drafted the work or revised it critically for important intellectual content;
approved the completed version, and are accountable for all aspects of the
work in ensuring that questionsrelated to the accuracyor integrity of any part
of the work are appropriately investigated and resolved. J.L., Y.S. and J.N.
have read and approved the final manuscript.
https://doi.org/10.1038/s44168-024-00147-9 Article
npj Climate Action | (2024) 3:70 7

Competing interests
The author declares no competing interests.
Additional information
Supplementary information The online version contains
supplementary material available at
https://doi.org/10.1038/s44168-024-00147-9.
Correspondence and requests for materials should be addressed to
Yves Steinebach.
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