Variable

Test statistic

P-value

Stationary or non-stationary^a

lnCO₂

−1.1463

0.5509

Non-stationary

lnGDP

−0.7816

0.8237

Non-stationary

lnGDPSQ

−0.7098

0.8426

Non-stationary

lnEN

−2.1039

0.2433

Non-stationary

lnOPEN

−1.6452

0.4593

Non-stationary

lnUR

−2.0127

0.2815

Non-stationary

lnFDI

−2.9526

0.0396

Non-stationary (only at 1% significance level)