Average global temperatures did not rise for 12 years, 2002 to 2014. In the next several years, two big El Ninos, natural phenomena, bumped global temperatures up. But since then, the global temperatures have declined and seem to be plateauing as they did in the 2002 to 2014 period. Then as now, CO2 concentration is continuing to rise without commensurate rise in global temperatures.
Also, there is a new study that says man made aerosols have decreased significantly since 2000. Because aerosols are believed to reflect the sun’s rays, preventing them in reaching the Earth’s surface, the reduction in aerosols should result in increasing global temperatures.
One could conclude that increased CO2 is not very effective in raising temperatures and further some thing else is causing cooling despite the reduction of aerosols.