Embodied Carbon Accounting for Forest Industry Trade in BRICS Countries: An MRIO Modeling Approach

Abstract

A multi-regional input-output (MRIO) model was constructed to measure and compare the trade-induced carbon emissions within the forest industry among the BRICS countries: Brazil, Russia, India, China, and South Africa. The results indicate the following: (1) The primary source of import/export-related carbon emissions from the forest industry in BRICS countries is the trade of paper products, with the exception of Russia, where wood products significantly contribute to its export-related carbon emissions. (2) The net carbon emissions from forest industry trade in BRICS countries underwent varying degrees of volatility during the period from 2008 to 2013. (3) China and Russia exhibited notably higher levels of trade-induced carbon emissions in their forest industries compared to other BRICS nations, while the scale of embodied carbon emissions from international trade in the forest industry of South Africa, Brazil, and India remained relatively similar. (4) The trade-induced carbon emissions of the forest industry in BRICS countries were predominantly export-oriented between 1995 and 2018. Therefore, it is recommended that BRICS nations prioritize addressing carbon emissions within the forest industry’s trade sector. Collaborative efforts should be intensified to promote cleaner development pathways, foster sustainable economic growth, and take a more proactive stance in global climate change negotiations.

1. Introduction

Global warming has been occurring in recent years, and climate issues are becoming a major threat to current lifestyles. Carbon dioxide emissions further exacerbate the global greenhouse effect, adversely affecting economic and social development, and ecosystem security [1]. The Paris Agreement sets the core objective of limiting the increase in the global average temperature to 2 °C in the 21st century and working to limit it to 1.5 °C. The Glasgow Climate Pact further calls for anthropogenic CO₂ emissions to reach net zero by the mid-21st century [2]. Since then, various emission reduction policies and measures have been introduced in countries around the world. Currently, carbon emission measurement based on producer responsibility accounting ignores the trade-embodied carbon generated by international trade transfers. At the same time, due to the gradual realization of net-zero emissions from domestic production [3], the issue of import trade-embodied carbon emissions has also gained the attention of scholars. From 1995 to the present, international trade-embodied carbon emissions have accounted for about one-fourth of the global total carbon emissions. Moreover, with the continuous increase in global total carbon emissions, international trade-embodied carbon emissions have also been on the rise. In order to achieve the goal of global economic decarbonization at an early date, there is an urgent need for research on trade-embodied carbon.

The International Federation of Institutes for Advanced Studies (IFIAS) Working Group on Energy Analysis introduced the concept of “embodied” in 1974 [4]. This concept was developed to quantify the total resource consumption, both direct and indirect, involved in the production of a product or service. The term “embodied“ was coined to describe this approach [5]. In accordance with the defined scope of the United Nations Framework Convention on Climate Change (UNFCCC), “Embodied carbon” encompasses direct and indirect carbon dioxide emissions associated with the entire lifecycle of commodities. This lifecycle spans from raw material acquisition and manufacturing to processing, storage, transportation, distribution, and ultimately consumer sale. This concept is also referred to interchangeably as “emissions embodied in trade (EET)”. Wyckoff and Roop [6] extensively examine the concept of embodied carbon in imports, providing a thorough analysis from both environmental and policy standpoints. They emphasize how the concept of embodied carbon in trade could potentially distort national greenhouse gas emission data, thereby affecting the overall effectiveness of international agreements on greenhouse gas emissions. This paper is widely acknowledged within the academic community as a pioneering achievement in the study of embodied carbon in international trade.

2. Progress in Modeling Research

Quantifying the precise extent of trade-induced carbon emissions can play a pivotal role in transforming concealed carbon consumption into transparent accountability. By accurately measuring trade-related carbon emissions, we can distinctly outline the assignment of responsibility for carbon footprints, thus enhancing the effectiveness of global climate governance strategies. The measurement of embodied carbon emissions from trade generally employs two primary methodologies: the process analysis approach and the input-output approach. The process analysis method involves identifying and documenting carbon emissions and flow pathways of input factors, raw materials, and energy throughout the cyclical life cycle of products and services. It is well-suited for micro-level studies focused on the carbon emissions of individual products. While this approach is effective for quantifying carbon emissions from specific products or services, it demands high-quality data, involves relatively complex data collection, and has limited applicability for macro-level studies aiming to measure carbon emissions across diverse industries and countries. Consequently, the input-output analysis model has gained widespread adoption globally and has become the predominant approach for studying carbon emissions resulting from regional trade.

In 1951, the American economist Wassily Leontief [7] introduced the input-output model. Later, in 1970, he extended its application to the analysis of economic structures and their environmental impacts [8]. This groundbreaking adaptation not only enabled the utilization of the input-output model in economic analyses but also facilitated the examination of the environmental repercussions of economic activities. This pioneering effort provided a significant analytical tool for uncovering the intricate connections between economic endeavors and the environment, as well as for devising strategies to promote sustainable development. Depending on the focus of investigation, the input-output model can be categorized into three distinct types: Single-Region Input-Output (SRIO), Bilateral Trade Input-Output (BTIO), and Multi-Region Input-Output (MIRO) or Multi-Regional Input-Output (MRIO) [9].

For example, Huang and Zhao [10] measured trade-embodied carbon emissions in three Chinese provinces from 2000 to 2014. They used financial scale development, financial efficiency, and financialization to define the level of regional financial development. The study found that the net export embodied carbon of most provinces began to rise in 2006 and declined in 2010. Furthermore, there is regional heterogeneity in the impact of financial development on trade-embodied carbon emissions. In another study, Wieland et al. [11] derived two extensions from the energy supply-use dataset to study the scope of material flows and their attribution to sectors in input-output tables. The SRIO model was applied to measure and compare them with energy footprints in the global multiregional input-output dataset EXIOBASE. The study found that the ranking of final demand footprints is sensitive to the design of the extensions. Moreover, the results of the study suggest that for countries such as Australia and Norway, the supply extension results can be twice as large as the use extension footprint.

In the case of bilateral trade, MRIO is mostly used to study the degree of embodied carbon surplus and deficit between major trading partners, such as China–US, China–Japan, China–Korea, China–Europe, and others. For example, in the period of 2000–2011, the embodied carbon emissions of China–Japan trade were measured based on the non-competitive input-output table in WIOD. Ma et al. [12] also used the non-competitive input-output table in WIOD to measure the embodied carbon of trade between China and Japan using the MRIO model. The results indicated a significant imbalance in the embodied carbon emissions of trade between China and Japan from 2000 to 2011. China had a large embodied carbon surplus with Japan, which showed a tendency to expand, making Japan dependent on China as a “pollution shelter”. Moreover, Zheng et al. [13] utilized the MRIO model based on the input-output table and direct carbon emission data in the WIOD database to calculate the embodied carbon emissions in the trade process between China and other BRICS countries and the G7. The study objectively analyzed the reasons for the growth of China’s embodied carbon emissions in trade with other BRICS countries and the G7, taking into account the real emission situation and the trend of change. The aim was to provide suggestions for the reform and development of China’s foreign trade, energy conservation, and emission reduction.

Multi-regional input-output models are often used to jointly measure trade-embodied carbon in multiple regions. For instance, Wang et al. [14] proposed a multi-step forecasting method to simulate bilateral trade-embodied carbon emissions based on input-output analysis and panel regression modeling. They measured the trade-embodied carbon emissions between China and Australia in the period of 2000–2014. The results indicate a significant increase in China’s net trade-embodied carbon outflows to Australia, primarily concentrated in the textile and heavy industry sectors. Using the 2013 version of the WIOD database, Wang and Song [15] employed the MRIO model to measure the UK’s coal consumption from both the production side and the consumption side. The study showed that between 1995–2009, both consumption-based and production-based coal consumption declined. However, consumption-based coal consumption increased between 1995–2007. The UK is identified as a net importer of carbon, with coal consumption flow mainly reflected in exports to developed countries and imports from developing countries. Peng et al. [16] quantified the embodied CO₂ emissions of China’s forest and wood products industry in international trade using the MRIO model based on the WIOD database. The study revealed that carbon emissions from the producer perspective are four times higher than those from the consumer perspective. China has a net embodied carbon outflow in the trade of forest and wood products, with the United States being the largest importer from China. Moreover, the trade-embodied carbon emissions from the furniture industry are significantly higher than those from the timber and paper industries. In another study, Wang et al. [17] constructed an MRIO model based on the Eora database. They measured the embodied carbon emission intensity of countries and regions along the “Belt and Road” in terms of demand. The results demonstrated that the demand from countries along the “Belt and Road” has an increasingly important impact on China’s economy and carbon emissions. However, the embodied carbon intensity of the demand from these countries is higher than that from other countries in China. This implies that China needs to emit more carbon emissions to achieve the benefits of the division of labor with these countries, particularly in the South Asian region.

3. Methodology

Trade Embodied Carbon is assessed using the input-output method. This approach involves incorporating trade within traditional input-output models. It begins with calculating carbon emission factors for each sector based on input-output tables, followed by determining carbon dioxide emissions resulting from trade, known as trade embodied carbon emissions.

Within the context of input-output analysis, the single-region input-output model is employed to quantify changes in the input-output dynamics of an individual country engaged in international trade. This model offers operational simplicity and requires minimal data. However, it does have certain limitations. Primarily, the model assumes uniform technology across nations in goods production, ignoring variations in energy composition and production methods across different countries. This can result in an overestimation of carbon emissions. Secondly, the model lacks differentiation between diverse trading partner countries, treating all trade partners as a collective entity. As a result, it struggles to accurately portray the embodied carbon emissions stemming from bilateral trade interactions.

In contrast, the multiregional input-output model integrates various countries and sectors into a unified input-output framework. It departs from the assumption of technological homogeneity to account for disparities in carbon emissions resulting from technological differences. Moreover, this model categorizes products into intermediate and final demand groups, enabling a more nuanced exploration of the role of processing trade in product manufacturing. The model adeptly traces the origins and destinations of products, encompassing industrial sectors across different countries in its analysis. This comprehensive approach enables a more precise and refined assessment of carbon emissions.

Considering these factors, this study opts to utilize a multi-regional input-output model to evaluate trade-induced carbon. By doing so, it aims to comprehensively and accurately analyze the impact of trade activities on carbon emissions.

3.1. Assumptions Underlying the MRIO Model

Suppose there are n countries, forming the multiregional non-competitive input-output table as illustrated in

Table 1. Multi-regional non-competitive input-output table.

	Output	Intermediate Use by Countries					End-Use by Countries					Total Output
Input		Country r	…	Country s	…	Country n	Country r	…	Country s	…	Country n
National intermediate inputs	Country r	$x^{rr}$	…	$x^{rs}$	…	$x^{rn}$	$Y^{rr}$	…	$Y^{rs}$	…	$Y^{rn}$	$X^r$
	……	…	…	…	…	…	…	…	…	…	…	…
	Country s	$x^{sr}$	…	$x^{\mathrm{ss}}$	…	$x^{sn}$	$Y^{sr}$	…	$Y^{ss}$	…	$Y^{sn}$	$X^s$
	……	…	…	…	…	…	…	…	…	…	…	…
	Country n	$x^{nr}$	…	$x^{ns}$	…	$x^{nn}$	$Y^{nr}$	…	$Y^{ns}$	…	$Y^{nn}$	$X^n$
Accountancy		$N^r$	…	$N^s$	…	$N^n$
Total intput		$X^{\prime \mathrm{r}}$	…	$X^{\prime \mathrm{s}}$	…	$X^{\prime \mathrm{n}}$

:

In Table 1, for a country r, there exists another country $s (s\ne r)$ representing a different country. The element located in the first quadrant, x^rs (r, s ∈ (1, 2, …, n)), represents the exports of country r to country s. The matrix $x^{rr}$ denotes the intermediate inputs used by country r for its own production. The element $Y^{rs}$ in the second quadrant represents the matrix of final demand for country r products exported to country s. The matrix $Y^{rr}$ denotes the final demand for country r products used for final consumption in the home country. $X^r$ denotes the vector of the total output of country r. In the third quadrant, $N^r$ denotes the vector of value added for country r, which represents the vector of initial inputs. $X^{\prime r}$ denotes the total input vector for country r.

In country $r$, the national economy comprises $k$ industries. The intermediate input matrix $x^{rs}$ is a $k\ast k$ matrix where each element $x_{ij}^{rs}$ (i, j ∈ (1, 2, …, k)) represents the inputs from industry $i$ in country $r$ to industry $j$ in country $s$in the production process. The final demand matrix $Y^{rs}$ is a column vector ${\left[Y_1^{rs},\dots ,Y_i^{rs},\dots .,Y_k^{rs}\right]}^T$, where each element $Y_i^{rs}$ represents the value of country r sector $i$ final exports to country $s$.

3.2. MRIO-Based Model for Measuring Trade-Embodied Carbon

Based on the aforementioned settings, we can construct the following multi-regional input-output row model:

$$X=AX+Y$$

(1)

The expanded equation is illustrated below:

$$\left[\begin{array}{c}{X}^1\\ X^2\\ ⋮\\ X^n\end{array}\right]=\left[\begin{array}{cccc}{A}^{11}& A^{12}& \cdots & A^{1n}\\ A^{21}& A^{22}& \cdots & A^{2n}\\ ⋮& ⋮& \ddots & ⋮\\ A^{n1}& A^{n2}& \cdots & A^{nn}\end{array}\right]·\left[\begin{array}{c}{X}^1\\ X^2\\ ⋮\\ X^n\end{array}\right]+\left[\begin{array}{c}{Y}^1\\ Y^2\\ ⋮\\ Y^n\end{array}\right]$$

(2)

In this context: X represents the total gross output. A stands for the matrix of direct consumption coefficients, with the elements corresponding to the direct consumption coefficients associated with each sector in each country. Y signifies the final demand. Let us further derive the above equation:

$$X={\left(I-A\right)}^{-1}\ast Y$$

(3)

where ${\left(I-A\right)}^{-1}$ represents the Leontief inverse matrix.

Integrating the concept of embodied carbon into the input-output methodology requires the inclusion of the direct carbon emission coefficient in the formulation of a model for quantifying embodied carbon emissions in trade. Let the direct carbon emission coefficient be denoted as “$ec$”, with its element $e{c}_j$ representing the carbon emissions directly generated by sector j for each unit of output. By incorporating this coefficient into the input-output framework, we can calculate the comprehensive carbon emission coefficient matrix as follows:

$$E^d=ec\ast {\left(I-A\right)}^{-1}$$

(4)

The left-hand side of the equation, denoted as $E^d$, represents the total carbon emissions per unit of finished output.

Embodied carbon emissions from trade can be calculated using the following formula:

$$F=E^d\ast T=ec\ast {\left(I-A\right)}^{-1}$$

(5)

where T is the trade vector, which can be categorized into import trade vector, export trade vector, and net export trade vector based on the direction of trade flow. Its elements represent the trade volume of sector$i$. F represents the embodied carbon emissions from trade.$T_i$ represents the trade volume of sector $i$, and F represents the embodied carbon emissions from trade.

3.3. Models for Measuring Embodied Carbon in Exports

Let there be a country r and other countries s. The export trade volume from country r to country $s$ represents the value of all products flowing from country r to country s. Based on Table 1, the export trade volume from country r to country s can be calculated as follows:

$$T_{ex}^r={\sum }_{s=1,s\ne r}^n{\sum }_{j=1}^k{x}_{ij}^{rs}+{\sum }_{s=1,s\ne r}^n{Y}_j^{rs}$$

(6)

The first term on the right-hand side of the equation represents the value of products from each sector in country $r$ used as intermediate inputs in other countries or regions. The second term represents the value of products from each sector in country r as final demand in other countries or regions. These two terms together contribute to the total export trade volume of country r.

Then the calculation of Embodied Emissions within Export (EEE) for country r is as follows:

$$EE{E}^r=e{c}^r\ast {\left(I-A^r\right)}^{-1}\ast T_{ex}^r$$

(7)

where $e{c}^r$ is the direct carbon emission row vector for country $r$, with $e{c}_j^r$ representing the direct carbon emission factor for sector $j$ of country $r$, and $A^r$ is the direct consumption matrix for country $r$. $T_{ex}^r$ is a diagonal matrix, where each element on the diagonal represents the volume of export trade in each sector of country $r$.

3.4. Import-Embodied Carbon Modeling

Imports encompass all the commodities and services entering a nation from other countries or regions. In the context of the input-output table, imports are characterized as including all products used for both intermediate and final applications. Therefore, the trade of country $r$ in imports originating from country $s$ can be expressed as follows:

$$T_{im}^{sr}={\sum }_{s=1,s\ne r}^n{\sum }_{i=1}^k{x}_{ij}^{sr}+{\sum }_{s=1,s\ne r}^n{Y}_j^{sr}$$

(8)

The initial component of the equation on the right-hand side represents the value of each sectoral item imported by country $r$ from country $s$ for intermediate usage. The subsequent component signifies the value of each sectoral item imported by country $r$ from country $s$ to fulfill the final demand. On the left side of $T_{im}^{sr}$ the import trade vector is indicated; essentially, it represents the value of each sectoral item imported by country $r$ from country $s$.

Consequently, the calculation of Embodied Emissions within Imports (EEI) for country $r$ from country $s$ is as follows:

$$EE{I}^{sr}=e{c}^s\ast {\left(I-A^s\right)}^{-1}\ast T_{im}^{sr}$$

(9)

Then, the embodied carbon emissions from country $r$ import trade with each country or region are summed to obtain the total embodied carbon emissions from country $r$ import trade. It can be calculated as follows:

$$EE{I}^r={{\displaystyle \sum }}_{s=1,s\ne r}^{n}EE{I}^{rs}$$

(10)

3.5. Modeling of Embodied Carbon in Net Exports

The calculation of net export trade, also referred to as Embodied Emissions of Trade Balance (EEB) is outlined below:

$$EEB=EE{E}^r-EE{I}^r$$

(11)

4. Data Sources and Processing

4.1. Data Sources

The data used in this study are sourced from the Organization for Economic Co-operation and Development (OECD). The trade-embodied carbon emissions of the forest industry in BRICS countries from 1995 to 2018 were measured using the most recent release of the non-competitive input-output tables (ICIO) in the OECD’s 2021 edition. Carbon emissions were calculated based on three different accounting methods, major energy use, and international trade volume obtained from customs ports, as well as value-added.

4.2. Industry Consolidation

The forest industry specifically refers to the secondary sector that utilizes forest resources for processing and reproduction [18,19]. According to the International Standard Industry Classification (ISIC), this study defines the scope of the “forest industry” as encompassing wood and paper products. The following table displays a cross-reference of forest industry codes as published in the OECD database’s ICIO (

Table 2. Forest Industry Code Cross Reference.

Industrial Classification	ICIO Industry Name	ICIO Industry Codes	ISIC Rev. 4 Industry Codes
Wood forest products industry	Wood, wood products, and cork products industry	D16	C16
Paper forest products industry	Paper products and printed matter industry	D17T18	C17–C18
Forest products processing and manufacturing	Wood products, paper products, and printed matter industry	D16T18	C16–C18

):

5. Measurement of Embodied Carbon Emissions in Forest Industry Trade in BRICS Countries

A multi-regional input-output model is developed to assess the trade-embodied carbon emissions within the forest industry across the BRICS countries, with separate analyses conducted for each individual country.

5.1. Measurement of Embodied Carbon Emissions in Brazilian Forest Industry Trade

As depicted in Figure 1, the embodied carbon emissions resulting from net exports of the Brazilian forest industry are predominantly positive, indicating that this industry’s embodied carbon emissions flow outwards during the trade process, making it a net exporter of embodied carbon. Examining the trend, the magnitude of net outflow of embodied carbon from Brazilian forest industry trade has generally expanded over time, albeit with noticeable fluctuations. The period from 1995 to 2003 witnessed a rapid increase, with an average annual growth rate of 69.67%. Subsequently, from 2003 to 2009, a clear downward trend emerged, followed by a subsequent rise until 2018. In terms of import and export flows, the trend in export embodied carbon emissions closely mirrors that of net exports, displaying a pattern of initial rise, followed by a decline, and then another rise, with consistent turning points. On the other hand, the import of embodied carbon emissions generally experienced a smaller decline, from 1.116 Mt to 0.524 Mt, representing a decrease of 53.05%. Notably, two distinct fluctuations occurred, one during the period of 1999–2001 and the other from 2007–2010, both indicating a sharp increase in short-term import demand.

Among them, the trend of trade-embodied carbon emissions in the wood products industry is illustrated in Figure 2. This industry consistently exhibits a net outflow of trade-embodied carbon emissions. However, the magnitude of the net outflow aligns closely with the trend of export trade-embodied carbon emissions due to the significant disparity between the imports and exports of trade-embodied carbon emissions. The level of imported embodied carbon emissions remains consistently low, ranging from 0 to 0.1 Mt, which is generally consistent with the overall embodied carbon emissions of the forest products industry. On the other hand, embodied carbon emissions from exports of wood products experienced continuous growth from 1995 to 2004, with an average annual growth rate of 14.55%. It reached its peak at 0.924 Mt during this period. Subsequently, there was a continuous decline in emissions over the following seven years, reaching 0.273 Mt in 2011, which represented a decrease of over 70%. However, emissions rebounded afterward, albeit at a slower rate compared to the previous upward phase, with an average annual growth rate of only 11.61%. By 2018, emissions reached 0.589 Mt.

Among them, the trend of trade-embodied carbon emissions in the paper products industry is depicted in Figure 3. The trend of trade-embodied carbon emissions in this industry closely mirrors that of the forest industry as a whole. Initially, there was a continuous transfer of embodied carbon to the home country until 1999. However, after that, the paper products industry became a net exporter of trade-embodied carbon emissions. In comparison to wood products, the paper products industry exhibits higher trade-embodied carbon emissions. Its export-embodied carbon emissions reached a peak of 3.373 Mt in 2018, accounting for 85.11% of the forest industry’s total emissions. Throughout most of the study period, the scale of embodied carbon emissions outflow from paper products constituted more than 80% of the forest industry’s total emissions, with the lowest share recorded in 2004 at 68.74%.

From the perspective of embodied carbon emissions from imports, the share of paper products is even higher, with the majority of periods surpassing 90%. The lowest share was observed in 2017 at 88.47%. This can be attributed to the continuous decline in embodied carbon emissions from imports of paper products after 2009, resulting in relatively lower values in 2017. In contrast, the embodied carbon emissions from imports of wood products experienced an upward phase during the same period.

Taken together, the changes in embodied carbon emissions from trade in the Brazilian forest industry have undergone a “rising-declining-rising” phase of development, with a larger proportion attributed to paper products and a smaller proportion to wood products, particularly in the import direction. This suggests that the Brazilian forest industry has predominantly been a net exporter of embodied carbon emissions during the study period, with paper products accounting for the majority of the total emissions.

5.2. Measurement of Embodied Carbon in Russian Forest Industry Trade

Figure 4 illustrates the trajectory of embodied carbon emissions within Russia’s forest industry trade. Overall, Russia’s forest industry shows a net outflow of carbon emissions in international trade, indicating that the nation emits carbon in this sector’s trade. However, this net outflow is gradually decreasing over time. When examining trade direction, carbon emissions attributed to imported trade remain consistently low, while those linked to export trade mirror the trend of the net export curve. This suggests a pronounced export-oriented focus in Russia’s forest industry carbon emissions. A closer analysis of the graph’s temporal pattern reveals a significant decline of 42% in embodied carbon emissions from forest industry exports during the period between 1995 and 1997. Following this, there was a partial recovery from 1998 to 2000, peaking at 26.295 Mt. Subsequently, export-related carbon emissions continued to decrease at an average annual rate of 6.34% until 2013, reaching a minimum of 8.212 Mt. Interestingly, a gradual resurgence in export embodied carbon emissions is evident between 2013 and 2018, in contrast to the reverse trend observed in import-oriented emissions during the same period.

The trajectory of embodied carbon emissions within the wood products industry’s trade is depicted in Figure 5. The graph highlights that the embodied carbon associated with wood product trade displays a consistent net outflow trend, closely aligning with the overall pattern of the forest products industry. Focusing on exports, the embodied carbon emissions from wood products exhibit a U-shaped pattern before 1999. Subsequently, a decelerating downward trend emerges, with emissions plummeting to a nadir of 8.345 Mt in 2009, followed by steady growth and a slight increase to 11.476 Mt in 2018. In contrast, the influx of embodied carbon emissions due to wood product imports maintains an upward trajectory, reaching a relative zenith of 0.664 Mt in 2008. However, there was a sharp 35.84% drop the following year, before experiencing swift recovery and peaking at 0.754 Mt in 2012. Since 2013, import-related embodied carbon emissions undergo a steep decline, reaching a mere 0.291 Mt in 2018, constituting only 3.88% of export-related embodied carbon emissions for the same year. In terms of proportion, imported embodied carbon emissions exert a minor influence on the net exported embodied carbon emissions. The percentage of imported embodied carbon within the total imports fell from 24.16% in 1995 to 19.49% in 2018. Conversely, the proportion of embodied carbon emissions from wood products has consistently remained above 50%, reaching its pinnacle at 65.38% in 2018. This underscores the substantial and escalating impact of wood products’ export-oriented embodied carbon emissions in Russia’s forest industry trade, while the effect of imports remains relatively modest.

Figure 6 illustrates the trajectory of embodied carbon emissions within paper product industry trade. The industry’s trade-related embodied carbon emissions have consistently shown a net outflow pattern, closely aligning with the overall trend. Since 2000, the embodied carbon emissions stemming from paper product exports have sustained a gradual decline, with an average annual reduction of 5.14%, decreasing from 10.262 Mt in 2000 to 3.973 Mt in 2018. Notably, this trend has exhibited stability without significant oscillations during this period. In contrast, the embodied carbon emissions attributed to paper product imports have displayed a gradual upward trend, characterized by an average annual growth rate of 0.84%. However, variations in the trend are notable across different periods. Preceding 2008, import-related embodied carbon emissions exhibited a consistent increase, with an average annual growth rate of 5.94%, peaking at 2.099 Mt in 2008. Subsequently, between 2009 and 2015, an inverted U-shaped pattern emerged, rebounding to 2.044 Mt in 2011 before resuming a declining trend. Considering the relative magnitude, the proportion of embodied carbon emissions contributed by paper product exports has essentially stabilized at approximately 35% of the total. In contrast, the share of embodied carbon emissions attributed to imports has experienced a slight rise, ascending from 75.84% in 1995 to 80.51% in 2018. This highlights the substantial contribution of paper products to the embodied carbon emissions in import trade, indicating a trend of continuous increase, while the contribution of exports remains relatively consistent and represents a smaller proportion of the overall total.

A comprehensive analysis reveals a prevailing downward trajectory in trade embodied carbon emissions within Russia’s forest industry. This trend is characterized by a net outflow in both import and export directions. In terms of the industrial composition of these emissions, wood products predominantly shape the export landscape, whereas paper products play a leading role in imports.

5.3. Measurement of Embodied Carbon in Indian Forest Industry Trade

The trend of embodied carbon emissions from trade in the Indian forest industry is presented in Figure 7. In terms of the net flow of embodied carbon in the forest industry, India has been a net importer of embodied carbon for most of the period, with the outflow scale expanding year by year. Only in 2013 did it experience a net outflow, reaching a peak of 0.344 Mt. Comparing Figure 7, the shape of the net outflow curve of embodied carbon is similar to that of exports after 2001, which aligns with the situation in other BRIC countries. However, as the curves of embodied carbon emissions from import and export trade are closer, and the import curve is consistently above the export curve, it indicates that India’s forest industry trade is import-dominated in terms of embodied carbon. From the import direction, India’s trade-embodied carbon emissions from the forest industry show a clear upward trend, with an average annual growth rate of 5.16%, increasing from 1.116 Mt in 1995 to 3.553 Mt in 2018. From the export direction, trade-embodied carbon emissions maintained a relatively rapid growth during the study period, with an average annual growth rate of 7.42%, higher than that of imports. However, there were significant fluctuations during 2011–2015, with an average fluctuation of 33.98% during that period. The largest amplitude occurred in 2012–2013, with an increase of up to 52.22%.

Among them, the trend of trade-embodied carbon emissions in the wood products industry is shown in Figure 8. From the figure, it is evident that the trade-embodied carbon emissions of this industry were predominantly in a net outflow state for the majority of the time, exhibiting a clear upward trend. However, after 2011, there was a sharp shock, leading to a net inflow in 2012, with a larger shock amplitude compared to the forest products industry as a whole. In terms of the trend of change, the net export embodied carbon of the wood products industry experienced a steady rise at an average annual growth rate of 10.13% before 2011. However, in 2012, it dropped by 106.54% to reach a historical low of −0.326 Mt, followed by a reversal in the following year, growing to 0.721 Mt. The trend of change in export embodied carbon emissions aligned with that of net exports. On the other hand, the magnitude of imported embodied carbon continued to grow until 2011, remaining relatively steady from 2011 to 2018 without any significant shocks. In comparison to the forest industry as a whole, the embodied carbon emissions from exports of wood products have significantly increased, with its share rising from 31.88% in 1995 to 50.11% in 2018, representing a transition from a secondary position to accounting for half of the embodied carbon emissions from trade in the forest industry. Furthermore, the upward trend of embodied carbon emissions from imports has been even more pronounced, with a larger increase. In 1995, its share was only 8.06%, whereas, in 2018, it reached as high as 63.09%. This indicates the growing significance of wood products in India’s embodied carbon emissions from trade in the forest industry, with imports playing an even more important role.

The trend of trade-embodied carbon emissions in the paper products industry is depicted in Figure 9. From the figure, it is evident that the trade-embodied carbon emissions of this industry have consistently shown a net inflow, with the scale of net inflow displaying a clear trend of expansion. In terms of the export direction, the embodied carbon emissions of the paper products industry have steadily increased at an average annual growth rate of 5.97%, rising from 0.376 Mt in 1995 to 1.428 Mt in 2018, without significant oscillations during the period. As for the import direction, there was a slight fluctuation during 2009–2013, with an increase of 36.63% from 2009 to 2011, followed by a decline of 19.74% from 2011 to 2013. However, overall, there was a clear upward trend, with embodied carbon emissions rising from 1.012 Mt in 1995 to 2.712 Mt in 2018, representing a growth of over 150%. In terms of relative scale, the embodied carbon emissions from exports of paper products have gradually decreased, with their share declining from 70% to 50%. Similarly, the embodied carbon emissions from imports have also experienced changes, with the share being as high as 90.68% in 1995, but declining to 76.33% in 2018. This indicates that, whether from imports or exports, the growth of embodied carbon emissions from paper products has been somewhat controlled, and its overall significance has gradually declined.

Taken together, the embodied carbon emissions in India’s forest industry trade exhibit an upward trend in both import and export directions, with the flow direction predominantly showing a net inflow. Furthermore, there has been a significant change in the composition of products, particularly in the direction of imports, where the proportion of paper products has gradually decreased, while the importance of wood products has progressively increased, with the latter experiencing a much higher growth rate compared to the former.

5.4. Measurement Results of Embodied Carbon Emissions in China’s Forest Industry Trade

The trend of embodied carbon emissions from trade in China’s forest products industry is presented in Figure 10. As observed from the figure, China acted as a net exporter of embodied carbon from the forest products industry until 2015; however, since then, a trend of net inflow has emerged. Figure 10 portrays three distinct peaks in China’s net export of embodied carbon in the forest industry from 1995 to 2018. The initial peak surfaced in 2000, with import embodied carbon at 12.515 Mt and export embodied carbon at 25.833 Mt, both reaching their zeniths. This underscores the prosperous foreign trade in the forest industry during that period, characterized by significant embodied carbon flow, especially in exports, which reached its highest level during the study timeframe. The subsequent peaks occurred in 2007 and 2012, marking the culmination of embodied carbon emissions from exports and relatively lower imports. This suggests a relative reduction in embodied carbon inflows into the forest industry, while the increase in outflows propelled overall net outflows. Morphologically, the implied carbon from export trade closely aligns with the net export trend. It is crucial to emphasize the distinct trend in import-implied carbon. Before 2002, the volatility of import-implied carbon for the forest products industry differed from that of export trade, although the fluctuations followed the same direction. Between 2002 and 2012, it maintained a relatively stable trajectory, while from 2012 to 2018, it displayed a clear upward trend. This indicates that as trade advances, the import of implied carbon gradually increases, catering to domestic demand through imports. This consequently curtails the consumption of carbon stocks to some extent, thereby safeguarding carbon pool resources.

The trend of embodied carbon emissions from trade in the wood products industry is depicted in Figure 11. As evident from the figure, the trade’s embodied carbon in the wood products industry exhibits a net outflow pattern. However, since 2018, a net inflow has emerged for the first time, suggesting the potential for further expansion in the net inflow scale. Regarding the changing trend, the net export of embodied carbon in the wood products industry continued to rise until 2007, reaching its zenith at 12.237 Mt during the study period. Subsequently, it underwent a steep decline at a rate of −162.54% per year, even reaching −0.070 Mt in 2018. This marked the first reversal of the net flow of embodied carbon. In recent years, the scale of imported embodied carbon has shown a growing trend, particularly post-2012, with an impressive average annual growth rate of 14.34%. It culminated in a peak value of 6.925 Mt in 2018. Compared to the entire forest industry, the exported carbon emissions from wood products experienced consistent growth from 1995 to 2007, peaking at 13.811 Mt, signifying a growth of 457.17%. Concurrently, it held a 63.26% share, which then diminished. A brief rebound occurred between 2009 and 2012, followed by an overall declining trajectory from 2007 to 2018, causing the share to drop from 48.86% to 42.97% between 2012 and 2018, lower than that in 1995. Conversely, the share of imported embodied carbon in the overall picture continued to rise, expanding from 16.69% in 1995 to 38.99%, reaching a peak share of 42.60%. This trend underscores the gradually increasing significance of wood products in the context of embodied carbon emissions from imports within China’s forest industry.

The trend of embodied carbon emissions from trade in the paper products industry is depicted in Figure 12. As evident from the graph, the trade-related embodied carbon emissions of this industry exhibit an overall net outflow, albeit with occasional minor net inflows in certain years. In comparison to wood products, the export-oriented embodied carbon emissions of paper products demonstrated relative stability after peaking in 2000. However, import-related embodied carbon emissions continued to rise throughout the period from 1995 to 2018. In terms of exports, the embodied carbon emissions originating from paper products continued to expand at an average annual growth rate of 42.08%, reaching a pinnacle of 20.132 Mt in 2000. This peak accounted for 77.93% of the total embodied carbon emissions from exports within the forest industry. However, these emissions sharply plummeted to only 5.728 Mt in 2002, leading to a gradual reduction in their relative magnitude. By 2008, this proportion had decreased to 38.20%, signifying a shift from absolute dominance to a secondary position. Although a rebound occurred thereafter, the proportion only reached 57.03% in 2018, nearly matching the emissions of wood products and revealing a relatively consistent pattern. Regarding imports, the embodied carbon emissions attributed to paper products exhibited a steady rise with an average annual growth rate of 5.02%, culminating in a peak of 10.836 Mt in 2018. Despite the overall increase in emissions, its contribution to the entire figure diminished from 83.31% in 1995 to 61.01% in 2018. Overall, the embodied carbon emissions associated with paper products have been managed to a certain extent, both from an import and export perspective, resulting in a relatively balanced structure alongside wood products.

Taken together, changes in embodied carbon emissions from China’s forest products industry trade have undergone three distinct developmental spikes. Starting from 2012, there has been a notable transition toward a net inflow, accompanied by a significant shift in product composition. The proportion of paper products in the product mix gradually decreased, while the share of wood products relatively expanded, particularly in the context of imports, where the growth rate of the latter exceeded that of the former. Ultimately, this has led to the emergence of a relatively balanced pattern between paper and wood products.

5.5. Measurement of Embodied Carbon in South Africa’s Forest Industry Trade

The trend of embodied carbon emissions from trade in South Africa’s Forest industry is illustrated in Figure 13. South Africa’s Forest industry trade has consistently shown a net outflow of embodied carbon emissions, indicating that the country is a net exporter of embodied carbon. The trend aligns closely with the embodied carbon emissions from export trade, indicating that South Africa’s Forest industry is export-oriented in international trade. Comparing imports and exports, it is evident that the embodied carbon emissions from exports are significantly higher than those from imports, exhibiting greater fluctuation and increase. The average annual growth rate for export emissions is 4.48%, whereas, for imports, it is only 2.43%. In terms of the trend of change, both import and export embodied carbon emissions experienced declines in 2008. Import emissions decreased by 16.16%, while export emissions declined for two consecutive years, from 1.818 Mt to 1.16 Mt, representing a decline of 36.19%. Subsequently, both import and export emissions witnessed eight years of growth, leading to a rebound in export emissions to 1.877 Mt in 2018, surpassing the 2008 level for the first time. In different periods, export embodied carbon emissions expanded at an average annual growth rate of 7.56% from 1995 to 2008. From 2010 to 2018, the average annual growth rate slowed to 6.2%, indicating a slower pace of growth compared to the previous period. Import embodied carbon maintained a steady growth rate of 6.9% from 1995 to 2006, followed by a gradual decline until 2018.

Among them, the trend of trade-embodied carbon emissions in the wood products industry is shown in Figure 14. From the figure, it can be observed that the industry’s trade-embodied carbon continues to have a net outflow, and the scale of net outflow exhibits an upward trend, with an average annual growth rate of 6.43%. In terms of the export direction, the trend of embodied carbon emissions is generally similar to net exports, but the growth rate is slower, with an average annual growth rate of 5.16%. Notably, there was a significant decline after 2008, lasting for two consecutive years, with a total decrease of 32.29%. Regarding the import direction, the embodied carbon emissions of the wood products industry initially increased and then declined, showing an M-shaped trend in the middle. The emissions reached a relatively low point of 0.137 Mt in 2009 and have since maintained a stable development trend, hovering around 0.05 Mt after 2016. Compared to the forest industry as a whole, the embodied carbon emissions from the export of wood products exhibited a relatively slow growth rate before 2008, followed by an increase after the shock around 2008. In terms of relative magnitude, the share of embodied carbon emissions from wood product exports has consistently been low, steadily declining from 1995 to less than 30% in 2008, and then increasing to 47.26% in 2018. However, the share is even lower in the import direction, peaking at 13.88%, and declining to 2.56% in 2018. This suggests that the trade in wood products contributes relatively more to the embodied carbon emissions of the South African forest products industry while making a smaller contribution overall.

Among them, the trend of trade-embodied carbon emissions in the paper products industry is depicted in Figure 15. From the figure, it is evident that the industry’s trade-embodied carbon emissions continue to have a net outflow, and the scale of net outflow shows a clear expanding trend. Regarding the export direction, the embodied carbon emissions of the paper products industry exhibit an overall upward trend. However, there are more pronounced shocks before and after 2008. In 2008, the embodied carbon emissions from exports reached the highest point during the study period, reaching 1.277 Mt, followed by a decline to 0.792 Mt in 2010, which is only 62.02% of the maximum value. On the other hand, in the import direction, the embodied carbon emissions of paper products show a steady growth with an average annual growth rate of 3.42%, increasing from 0.239 Mt in 1995 to 0.518 Mt in 2018, albeit with smaller values compared to exports. In terms of relative scale, the share of embodied carbon emissions from the export of paper products increased from 57.40% in 1995 to 70.24% in 2008, dominating the forest industry as a whole. However, in 2018, it accounted for only 52.69%, lower than the level in 1995. Conversely, the trend of embodied carbon emissions from imports exhibited a decline followed by a rise. The share decreased from 75.16% in 1995 to 70.38% in 2007, and then fluctuated upward to 91.52% in 2018, reaching a historical high. This indicates that in South Africa’s Forest industry, the embodied carbon emissions from trade in paper products have relatively increased, while the share of exports has relatively declined, although the overall decline has been minimal.

Taken together, South Africa’s embodied carbon emissions from trade in the forest industry have shown an upward trend for both imports and exports, with the overall flow direction maintaining a net outward trend. Additionally, there has been a significant change in the product composition, with the proportion of paper products gradually expanding while Embodiedthe significance of wood products has diminished, particularly in imports.

6. Conclusions and Policy Recommendations

6.1. Conclusions

Through quantification and analysis of embodied carbon in the forest industry trade across BRICS countries, the following conclusions emerge:

(1)

Sectoral Structure of Embodied Carbon in Trade

Within the context of forest industry trade, paper products assert dominance in terms of embodied carbon emissions. However, upon examining embodied carbon emissions associated with wood products, Russia takes the lead, demonstrating a higher average of 8.66 million metric tons of embodied emissions in exports. Concerning embodied emissions within exports, the proportion of paper products in South Africa and Russia’s exports follows a trend of initial increase followed by subsequent decrease, while overall stability is maintained. In contrast, India’s share of paper products in export-related embodied carbon emissions experiences a continuous decline, eventually converging with that of wood products. On the other hand, the proportions of paper products in the exports of Brazil and China exhibit a dual trajectory of decline followed by resurgence, gradually approximating 1995 levels. When considering imports, the role of paper products from South Africa and Russia in embodied carbon emissions associated with the forest industry’s imports intensifies, particularly pronounced in South Africa where the share of imported embodied carbon has surged since 2016, consistently exceeding 90%. In contrast, the contribution of paper products to imported embodied carbon emissions diminishes in other BRICS nations, notably China, where it holds the lowest proportion and registers the most significant decline, hovering around 60%.

(2)

Trends in Embodied Carbon Emissions

Embodied carbon emissions resulting from forest industry trade among BRICS countries exhibit both commonalities and distinctions. The shared characteristic is evident in the fluctuation of trade embodied carbon emissions from net exports among these nations between 2008 and 2013. In 2009, all BRICS nations, except Brazil and India, witnessed a significant decrease in trade embodied carbon emissions. This shift can be primarily attributed to the global financial crisis of 2008, highlighting the direct impact of trade volume on trade embodied carbon emissions, along with a time lag. However, disparities in trade embodied carbon emissions among nations also come to the forefront. Year after year, a growing trend of net outflows of trade embodied carbon emissions from the forest industry is observed in Brazil, India, and South Africa. Brazil, in particular, experiences a remarkable average annual growth rate of 23.43%, whereas South Africa’s growth rate is more subdued at 5.82%. In contrast, the embodied carbon emissions associated with China and Russia’s net exports from the forest products industry progressively decline over time. Russia follows an upward trajectory after 2013, while China undergoes a reduction following three significant fluctuations in 2000, 2007, and 2012, resulting in respective increases of 57.61%, 10.01%, and 20.01% relative to the preceding year.

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Scale of Embodied Carbon Emissions from Trade

Throughout the study period, the magnitude of embodied carbon emissions resulting from international trade within the forest products industry remains relatively consistent among South Africa, Brazil, and India. Notably, South Africa records the smallest emission scale; however, its embodied emissions within exports continue to rise following its membership in the BRICS organization in 2011, thereby progressively narrowing the gap with other member nations. Spanning from 1995 to 1997, Russia’s international trade embodied carbon emissions from the forest industry significantly surpass those of other BRICS countries. Following fluctuating adjustments between 1998 and 1999, Russia’s trade embodied carbon emissions gradually recede, positioning it as the second-highest emitter within the BRICS consortium.

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Regarding the Net Flow of Embodied Carbon Emissions in Trade

Over the study period, South Africa and Russia emerge as net exporters of embodied carbon in the forest industry trade, releasing a substantial volume of embodied carbon emissions throughout their trade activities. In contrast, Brazil and China exhibit a net outflow trend, notwithstanding sporadic net inflows in specific years; overall, net outflows remain predominant. India operates as a net inflow nation until 2003, subsequently transitioning into a net outflow status. Worth noting is China’s evolving forest industry trade orientation, transitioning from export-centric to import-focused, particularly evident after 2012, marked by an average annual growth rate of 12.46% in imported embodied carbon.

6.2. Policy Recommendations

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Advocate Shared Responsibility for Carbon Emissions

The existing framework under the United Nations Framework Convention on Climate Change (UNFCCC) assigns carbon emission responsibilities based on the producer principle, potentially leading to the relocation of carbon-intensive industries to developing countries and exacerbating “carbon leakage.” To address this, the BRICS nations should champion the concept of shared responsibility for carbon emissions that encompasses both production and consumption. This principle would involve a proportional distribution of responsibilities between intermediate production and final consumption, thereby achieving a collective commitment to emissions reduction.

(2)

Enhance Negotiating Influence

Given the growing economic contributions of BRICS countries, they should unite with global partners to drive effective global carbon reduction efforts and actively engage in international climate negotiations. BRICS nations must advocate for the establishment of a new climate governance order characterized by mutual respect, reciprocity, and mutual benefits. By leveraging their roles as key global economies, the BRICS countries can strengthen their collective efforts to combat climate change and amplify their influence during negotiations.

(3)

Strengthen Forest Industry Collaboration and Promote CDM Implementation

BRICS nations should strengthen collaboration and facilitate the adoption of cleaner production technologies in developing countries. Financial and technical support should be extended to drive the effective implementation of the Clean Development Mechanism (CDM) and reduce the implicit carbon emissions associated with traded commodities. Brazil and Russia, as significant players in the forest industry, should lead the transition to greener practices, upgrade the entire industry value chain, and actively pioneer the research and application of green technologies to provide support for fellow BRICS nations. China, India, and other BRICS countries should actively seek technical cooperation, foster the growth of eco-friendly forest industries, align their strategies with the unique characteristics of their forest resources, and develop environmentally sustainable forest industry plans that enhance their technical capabilities.

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Optimize Trade Structure and Expand Markets

The diverse production, consumption, and trade structures of BRICS countries present opportunities for mutual learning and collaboration. Optimizing the trade structure of forest industry products to enhance their value and competitiveness is essential. While prioritizing economic value, special attention should be given to ecological value, prompting the promotion of low-carbon, high-value products in international markets. BRICS countries should prioritize the establishment of inclusive multilateral trade agreements, the reduction of trade barriers, and the strengthening of South-South cooperation to ensure equitable trade practices. Active participation in regional frameworks, such as the Asia-Pacific Free Trade Area and the Eurasian Economic Union, will drive international trade liberalization, elevate their voice, and amplify their impact in regional trade dynamics.

6.3. Limitation of This Study

In summary, this paper establishes a multi-regional input-output model to quantify and comparatively analyze the embodied carbon emissions of forest industry trade in the five BRICS countries: Brazil, Russia, India, China, and South Africa, spanning from 1995 to 2018. The study offers potential strategies for coordinated regional emission reduction. However, certain challenges persist, including data lag and a lack of differentiation between the sources of import-related and export-related carbon emissions. Subsequent research endeavors will delve deeper into scrutinizing the carbon emission flows among specific nations.