This is a joke, right?
So, it seems they just *made it up*
it appears to mean "we have a prompt instruction to greenwash the AI responses"
After some more digging here’s a bit more on this from: https://ecosia.helpscoutdocs.com/article/534-ecosia-chat-ai
Ecosia Chat - Ecosia Help Center

The Ecosia AI Chat can help you be more climate active every day. The chatbot is powered by OpenAI, but your queries are not used to train the AI model. The cha

@fasterandworse I use Ecosia because it's carbon negative. That's the product. I haven't been waiting for the opportunity to do some bullshit net-zero credit banking so people can justify doing the opposite.