Nancy Lindisfarne and Jonathan Neale write: Last week Greta Thunberg posted the picture above on her Twitter (X) account. Many people in the press criticized her because they themselves supported the Israeli bombing and opposed a ceasefire. Some of those people called her, ludicrously, antisemitic. There was also criticism from some climate activists in Germany, Austria and Israel. Beyond that, there was little open criticism from the climate movement, and much support on social media. This is a historic moment for the global climate movement. This article explains why.