The judge decided that because the science of climate change and counting climate related deaths relies on probabilities (surely all science does...) there was no clear link between climate change and deaths. He also said that it was not the activists responsibility to try to reduce emissions but the governments.
The government is in the middle of a massive road building programme and is planning on a massive airport expansion programme. The governments policies are quite simply causing the problem. The defendants were defiant and stated that they felt it WAS their responsibility to do something when the government was making such a mess of it.