Augmented Dickey-Fuller test (unit root test).
| Variable | At level I(0)t-statistic | Remark | At first difference I(1)t-statistic | Remark | Decision: H0 | Order of integration |
|---|---|---|---|---|---|---|
| Y | –4.673*** | Stationary | –4.321*** | Stationary | Reject | I(0) at 1% |
| X1 | –1.225 | Non-stationary | –4.022*** | Stationary | Reject | I(1) at 1% |
| X2 | –1.051 | Non-stationary | –4.343*** | Stationary | Reject | I(1) at 1% |
| X3 | –5.114*** | Stationary | –2.782*** | Stationary | Reject | I(0) at 1% |
| X4 | –2.501** | Stationary | –4.011*** | Stationary | Reject | I(0) at 5% |
| X5 | –5.140*** | Stationary | –5.822*** | Stationary | Reject | I(0) at 1% |
| X6 | –1.006 | Non-stationary | –4.311*** | Stationary | Reject | I(1) at 1% |
| X7 | –2.104** | Stationary | –3.701*** | Stationary | Reject | I(0) at 5% |
** and *** denote significance at the 5% and 1% levels, respectively. H0: series have a unit root.
We acknowledge the contribution of Prof N.C. Ehirim in proofreading the entire manuscript and model stabilization, data and structural framework.
EO, UO, BA, MO: Conceptualization, Data Analysis, Writing—original draft. CN, CT, ATA: Data curation, Formal analysis, Writing—original draft. CO, TI, IMN, KA: Methodology, Validation, Writing—review & editing. YA, EN, HA, KS: Software, Supervision, Writing—review & editing. OU, KE, OA, IO: Visualization, Project administration, Writing—review & editing. All authors read and approved the submitted version.
The authors declare that they have no conflicts of interest.
Not applicable.
Not applicable.
Not applicable.
Data for the study are publicly available in the World Bank Climate Change Knowledge Portal, Nasa Power, FAOSTAT, and the World Bank.
Not applicable.
© The Author(s) 2026.
Open Exploration maintains a neutral stance on jurisdictional claims in published institutional affiliations and maps. All opinions expressed in this article are the personal views of the author(s) and do not represent the stance of the editorial team or the publisher.