Politicians are chosen by the citizens. So the question could be rephrased to “how do we make a big portion of the world aware of the seriousness?”.
A web search for “how to convince your opponent” gives some great suggestions:
———————————————————— How to Convince Someone Ask them to share their thoughts. Match their type of reasoning -- if they're being emotional, appeal to their emotions; if they're relying on logic, be logical. Get them to lower their guard with a genuine compliment. Pose a counter-argument (without making them defensive). ————————————————————
This is quite counter intuitive: I would think that if you would tell the data and scientific method used to obtain the data you would be able to convince anyone, but not so.
Instead you have to open the discussion and have both sides on the table, which leads to ridiculous situations eg: a TV show gives a scientist who builds upon many years of research equal time to speak on some matter as a fancy vlogger with a quirky opinion.
The more noise you make the more you will be noticed. If people aren’t confronted with their actions, they have little chance to change their opinion and behaviour. It is important to be respectful while also making clear that change is needed, by each and everyone.