Lewis Hamilton has urged his fans to go vegan and said he feels like "giving up on everything" due to his concerns about the environment.
The 34-year-old, who is on the verge of winning a sixth Formula One world title, spelt out his feelings about the state of the world in three posts on Instagram.
Hamilton switched to a plant-based diet in 2017 and in September he helped launch a vegan burger restaurant in London.
Hamilton wrote: "Hey world, I hope everyone's enjoying their day. I'm sad right now with the thought of where this world is going.
"Extinction of our race becoming more and more likely as we over use our resources. The world is a messed up place. World leaders either uneducated or don't care about the environment at all.
"Agriculture farming is the largest pullutant (sic) we currently have by over 50 per cent, far more than our travel industry combined. I'm sad to see so many people, even close friends ignore what is happening daily.
Hamilton added: "Go vegan, it is the only way to truly save our planet today. It can be done so quickly, all you have to do is put your mind to it.
"Honestly I feel like giving up on everything. Shut down completely. Why bother when the world is such a mess and people don't seem to care. I'm going to take a moment away to gather my thoughts. Thank you to those of you who do give a damn about the world."