Macron and Trump's differences on climate policy have been a sticking point in their relationship for years, leading Macron to create his play on the U.S. president's rallying cry to "Make America Great Again."
Politico reported in 2017:
When Trump announced in June that he would yank the U.S. out of the Paris climate agreement, Macron spied an opportunity: Within hours, his office took a poke at Trump, unveiling a social media campaign around the tongue-in-cheek slogan "Make Our Planet Great Again," complete with a website where U.S. climate researchers could apply for residency and work in France.
Behind the viral tweet, retweeted 235,896 times, Macron's political message was clear: France would lead the world on climate change research and technology, leaving the United States to choke on coal fumes.