•This study focuses on multidimensional relationship among SAARC countries.•We explore country-level relationships of energy, agriculture, ISO 14001 and CO2 emissions.•India's has the highest CO2 emissions and therefore biggest opportunities to reduce emissions.•Benefits are found in reducing emissions by using renewable energy and ISO 14001 certification.•Insights benefit decision makers and policy makers wanting to invest in CO2 emission reductions. In this study, we investigate complex, country-level relationships between ISO 14001 certification, renewable energy consumption, access to electricity, agriculture, and CO2 emissions within the South Asian Association for Regional Cooperation (SAARC) countries. These countries are important to look at they contain 20% of the world's population, are investing in infrastructure, and are vulnerable to the impacts of CO2 emissions. There is a gap in the literature addressing all of these countries while using novel modeling to try and understand dynamic relationships across countries. In this study we use multiple models to examine data covering the years 2000 to 2014 starting with novel Grey Relational Analysis (GRA) models to compute the weights and ranking of countries based on CO2 emission. Next, using a Conservative (maximin) model, we check which country has the most CO2 emission issues among all countries based on weights obtained by Second Synthetic Grey Relational Analysis (SSGRA). Finally, a Grey preference by similarity to ideal solution (G-TOPSIS) methodology prioritizes the factors that have more intensely impact CO2 emissions. The results reveal that among all SAARC countries, India has substantial CO2 emission issues. We also find reductions in emissions from renewable energy consumption and the adoption of ISO 14001 certification in these countries. The outcomes of this study can assist organizations and policymakers in their decision-making and investments regarding CO2 reduction while simultaneously improving environmental sustainability practices.