Atmospheric CO2 concentration trend is observed to lag centuries behind the temperature trend. Thus CO2 can not act as a driver of climate change. This means that any human efforts to reduce global warming by reducing human CO2 emissions is doomed to failure, regardless how many countries, leaders and organizations have agreed with the UN in Paris and regardless how much money is spent.
But, Al Gore is back in the theaters and fake news media with his science fiction religion about man-made global warming. Unfortunately, many publicly funded agencies like NOAA and NASA have not corrected their websites and continue with pronouncements about reducing CO2 emissions in order to prevent various scary global warming/climate change scenarios.
Shaviv and Veizer  have shown that more than two thirds of the variance in the reconstructed tropical temperature variability over the Phanerozoic period (the last 570 million years) can be explained using the variable Cosmic Ray Flux (CRF). “On the other hand, it was shown that the reconstructed atmospheric CO2 variations do not appear to have any clear correlation with the reconstructed temperature.”(1)
And, “For the Phanerozoic, the estimates of atmospheric pCO2 levels are not only internally inconsistent, but they also do not show any correlation with the paleoclimate record.” (2) See figure 5 in this paper.
Here, once again, is a partial reference list of science indicating that CO2 changes follow temperature changes. Of course, the cause cannot follow the effect.
(3) Shaviv, N. J. (2005), On climate response to changes in the cosmic ray flux and radiative budget, J. Geophys. Res.,110,A08105, doi:10.1029/2004JA010866
(4) Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola, J.-M.,Basile, I., Benders, M., Chappellaz, J., Davis, M., Delayque, G., Delmotte, M., Kotlyakov, V.M., Legrand, M., Lipenkov, V.Y., Lorius, C., Pépin, L., Ritz, C., Saltzman, E., and Stievenard, M., 1999, Climate and atmospheric history of the past 4 20,000 years from the Vostok ice core, Antarctica:
Nature, v. 399, p. 429–436.
(5) Fischer, H., Wahlen, M., Smith, J., Mastroianni, D., and Deck, 1999, Ice core record of atmospheric CO2 around the last three glacial terminations: Science, v. 283, p. 1712–1714
(6) Mudelsee, M., 2001, The phase relations among atmospheric CO2 content, temperature and global ice volume over the past 420 ka: Quaternary Science Review, v. 20, p. 583–589.
(7) Monnin, E., Indermühle, A., Dällenbach, A., Flückiger, J., Stauffer, B., Stocker, T.R., Raynaud, D., and Barnola, J.M., 2001, Atmospheric CO2 concentrations over the last glacial terminations: Nature, v. 291, p. 112–114.
(8) Caillon, N., Severinghaus, J.P., Jouzel, J., Barnola, J.-M., Kang, J., and Lipenkov V.Y., 2003, Timing of atmospheric CO2 and Antarctic temperature changes across Termination III: Science, v. 299, p. 1728–1731.
(10) Veizer, J., Y. Godderis, and L. M. Francois (2000), Evidence for decoupling of atmospheric CO2 and global climate during the phanerozoic eon, Nature, 408, 698.
(11) Science provides the unambiguous answer George White October 2008 Revised July 2009 email@example.com. CO2 Forcing: Fact or Fiction. Many sources of information. Ice Core Data (ppt) Atmospheric Absorption (ppt) Satellite Observations (ppt) Ground Based Observations (ppt) http://www.slideserve.com/mandel/co2-forcing-fact-or-fiction