Page 60 - Read Online

Page 2 of 20 Han et al. Carbon Footprints 2025, 4, 25 https://dx.doi.org/10.20517/cf.2025.18

INTRODUCTION
Methane (CH ), the second most significant greenhouse gas (GHG), accounts for approximately one-fifth of
4
global GHG emissions. It is much more active in the atmosphere than carbon dioxide (CO ), with a global
2
warming potential over a 20-year period that is more than 80 times greater than that of CO emissions .
[1-3]
2
Given the pressing challenges of global climate change, mitigating CH emissions holds paramount
4
[4-7]
significance . The Belt and Road (B&R) Initiative - one of the largest and most geographically extensive
international development strategies - faces extensive use of fossil fuels and ruminant livestock, coupled
with limited mitigation measures, making CH emissions in this region a major concern.
4
Proposed by China in 2013 and inspired by the ancient Silk Road, the B&R Initiative encompassed over
two-thirds of the world's population and accounted for about one-third of global GDP as of 2016 . Most
[8,9]
B&R countries are developing economies experiencing rapid urbanization, industrialization, and
international trade growth, all of which may contribute to rising global GHG emissions [10-12] . In Central
Asian B&R countries such as Kazakhstan, coal represents around 50% of primary energy consumption.
Extensive underground coal mining in these areas often releases substantial amounts of CH emissions
4
through coal mine gas venting. Similarly, ruminant livestock farming, particularly cattle and buffalo rearing
in countries such as India and Pakistan, constitutes another major source of CH emissions. Moreover,
4
many countries are especially vulnerable to the impacts of climate change [13,14] . As the second most
important greenhouse gas, CH emissions has the advantage of rapid atmospheric response, meaning that
4
spatiotemporal analysis of CH emissions can provide valuable guidance for designing effective mitigation
4
policies. However, studies focusing on CH emissions in the B&R region, especially those examining
4
emission inequality and the drivers of CH growth, remain scarce.
4
Previous research has largely concentrated on the evolution of GHG emissions [7,15] , particularly in the B&R
countries [16-18] . Studies also examined electricity development and its carbon emissions [19,20] , drivers of total
carbon emission changes , and carbon peaking trends . With abundant energy resources [23,24] , the B&R
[21]
[22]
region plays an increasingly influential role in shaping the global economy, trade flows, emission patterns,
and climate trends [25,26] . While considerable attention has been paid to CO emissions, understanding the
2
trends and characteristics of CH emissions in the B&R region is both necessary and urgent.
4
Multi-regional input-output (MRIO) models have been widely applied to quantify resource and
environmental footprints, including energy [27,28] , air pollution , water , ecological impacts , renewable
[30]
[29]
[31]
energy , and GHG emissions . Most studies emphasized carbon emissions, focusing on topics such as the
[25]
[32]
[34]
[33]
pollution haven hypothesis , the B&R’s effect on global and Chinese CO emissions , mutual carbon
2
emissions and spillover effects between China and B&R countries , embodied carbon transfer flows [36-38] ,
[35]
emission inequality [39,40] , and the exchanges between embodied economic benefits and CO emissions . For
[41]
2
example, Fang et al. applied MRIO analysis to assess water, land, carbon, nitrogen, and phosphorus
footprints, finding that the B&R region was a net exporter of trade-embodied flows, except for virtual
water . Lu et al. showed that from 1995 to 2015, the B&R region contributed over 50% of the global carbon
[31]
footprint . Wang et al. examined India’s embodied carbon emissions in international trade finding, that
[40]
most of its exported CO emissions were destined for developed countries, while the majority of its
2
[42]
imported emissions originated from developing countries . Hou et al. analyzed CH emissions embodied
4
[25]
in B&R trade between 2004 and 2011 .
In recent years, inequality in CO emissions has been widely studied using methods such as the Lorenz
2
curve, Theil index, coefficient of variation, and Gini coefficient [43-46] . However, little attention has been given
to inequality in CH4 emissions. Tapio first proposed the decoupling theory to evaluate the relationship
[47]