Sketchbooks are a pretty ethical practice for the most part - there isn’t a lot of moral decisions to consider. There’s the usual environmental considerations, such as the type of paper you are using. It’s always a good thing to consider environmentally friendly/recycled sketchbooks. Some artists also like to travel to find references for their sketches. An example of this would be Ollie MacDonald Oulds, who traveled to Jamaica to inspire his drawings. Whilst this is a good way to find new subjects for your work, it can also heavily affect the environment - depending on how often you do it. It’s important to consider whether or not travelling is completely necessary, and if it is better to use other resources like google maps instead. There are other ethical things to consider such as diversity and representation. As always, an artists work must be diverse, so making sure you practice that and are able to draw a wide range of people in a respectful and accurate way is a must. A quote to support that is from Jesse Beason during a TED Talk about why representation is so important, “Representation matters, and I’ve come to believe deeply that reflective representation - seeing yourself, your experience, your people’s experience, in the places and positions that matter most in this world - is critical to meaningful civic engagement.” (2017). Using a sketchbook might be useful in this situation, as it allows you space to practice this.

You could also take this theme of morals down a different route - and instead focus on drawing immoral things. Take Jill Gibbon, for example; she is know for her sketches she drew in her sketchbook whilst attending arms fairs, disguised as a client. "Working undercover, artist Jill Gibbon sketches images of the surreal behind-the-scenes world of military fairs and expos to highlight how the arms trade treats missiles, tanks and bombs like any other commodity" (Vijaykumar, The Guardian, 2014). I’d say that for the most part, sketchbooks are a very ethical exercise.