No, it's the topic for this conversation as it is very specifically what Trump tweeted about. Hillary's emails is a topic for another conversation.
'Global warming' is real. It's existence is proven. The average temperature of the world is rising. It's a fact. Very few people don't accept that, so you're in a small minority there, yet again.
The causes are debated. Some seem to think it's just a coincidence that temperatures rocketed since the Industrial Revolution.
Trump's tweet is astoundingly ignorant. For a start, he's using an example of extreme weather conditions, a symptom of 'global warming'!