Contribution of agricultural land conversion to global GHG emissions: A meta-analysis

Greenhouse gases (GHG) have extensive environmental effects by trapping heat and causing climate change and air pollution. Land plays a key role in the global cycles of GHG (i.e., carbon dioxide (CO2), methane (CH4), and nitrogen oxide (N2O)), and land use change (LUC) can lead to the release of such gases into the atmosphere or the removal of them from the atmosphere. One of the most common forms of LUC is agricultural land conversion (ALC) where agri-cultural lands are converted for other uses. This study aimed to review 51 original papers from 1990 to 2020 that in-vestigate the contribution of ALC to GHG emissions from a spatiotemporal perspective using a meta-analysis method. The results of spatiotemporal effects on GHG emissions showed that the effects were significant. The emissions were affected by different continent regions representing the spatial effects. The most significant spatial effect was relevant to African and Asian countries. In addition, the quadratic relationship between ALC and GHG emissions had the highest significant coefficients, showing an upward concave curve. Therefore, increasing ALC to more than 8 % of available land led to increasing GHG emissions during the economic development process. The implications of the cur-rent study are important for policymakers from two perspectives. First, to achieve sustainable economic development, policymaking should prevent the conversion of more than 90 % of agricultural land to other uses based on the turning point of the second model. Second, policies to control global GHG emissions should take into account spatial effects (e.g., continental Africa and Asia), which show the highest contribution to GHG emissions.

Automated summary

Greenhouse gases have significant environmental effects, and land plays a key role in their global cycles. This study reviewed 51 papers to investigate the contribution of agricultural land conversion to greenhouse gas emissions. The results showed that the spatiotemporal effects were significant, and emissions were influenced by different continents, with African and Asian countries having the highest contribution. Additionally, there was a quadratic relationship between land conversion and emissions, indicating an upward concave curve. Policymakers should consider these findings when strategizing for sustainable economic development and controlling global greenhouse gas emissions.