MIAMI — Unchecked climate change has already changed Florida permanently and irreversibly — and the world has a limited window to stop it from getting worse, according to a new global report from the world’s top scientists. “The scientific evidence is unequivocal: climate change is a threat to human well-being and the health of the planet. Any further delay in concerted global action will miss a brief and rapidly closing window to secure a livable future,” says the United Nations’ Intergovernmental Panel on Climate Change report, released on Monday. The nearly 2,000-page report had a global fo…