Not sure why this is getting downvoted? He's right. The odds that global warming will stay below 1.5C are miniscule. I guess there may be PR benefits in pushing 1.5C because it's ambitious (shoot for the moon and land among the stars), but those PR benefits will be offset by the fact that anyone who does the tiniest bit of research will realize that it's bullshit! Not to mention that using 1.5C as a goal without lying is difficult.
"If we do <x> we'll be able to stay under 1.5C" <- lie
"If we don't do <y> we won't be able to stay under 1.5C" <- possibly true, but deceptive
"Our goal is to keep global warming under 1.5C" <- lie, a goal is by definition achievable and anyone who's giving statements on climate change knows that 1.5C is not achievable
"If we do <x> we'll be able to stay under 1.5C" <- lie
"If we don't do <y> we won't be able to stay under 1.5C" <- possibly true, but deceptive
"Our goal is to keep global warming under 1.5C" <- lie, a goal is by definition achievable and anyone who's giving statements on climate change knows that 1.5C is not achievable