I love it that the "believers" in climate change science also believe it is possible to meet this 1.5 degree target solely through the actions of a couple countries cutting back on CO2 emissions (when most of the developing world will still be increasing emissions for the foreseeable future, and with the human population rising dramatically). We simply do not know the relative effects of all the other climate variables out there - solar cycle changes, volcanic activity, etc. 

It is pure human folly (and arrogance) to believe we can somehow manage the atmospheric composition enough to effect the worldwide climate in any way. This is as much a new religion than anything else (and humans are very good at believing in things they don't understand). Humans are also very bad resource managers; even when it comes to something as relatively straightforward as managing ocean fisheries or wildlife populations, we are usually abject failures. It won't be any different with man-made CO2.