My trip to space made me realise we have only one Earth – it must live long and prosper | William Shatner

Star Trek prepared me to feel a connection with the universe. Instead, I felt terrible grief for our planet. At Cop15, our leaders must negotiate to protect it

Last year, at the age of 90, I had a life-changing experience. I went to space, after decades of playing a science-fiction character who was exploring the universe and building connections with many diverse life forms and cultures. I thought I would experience a similar feeling: a feeling of deep connection with the immensity around us, a deep call for endless exploration. A call to indeed boldly go where no one had gone before.

I was absolutely wrong. As I explained in my latest book, what I felt was totally different. I knew that many before me had experienced a greater sense of care while contemplating our planet from above, because they were struck by the apparent fragility of this suspended blue marble. I felt that too. But the strongest feeling, dominating everything else by far, was the deepest grief that I had ever experienced.