My oral surgeon suggested to remove upper half of the lower wisdom tooth since it's very close to nerve. is this safe?

Yes, it is.: Your oral surgeon is a expert in determining what is best for your overall dental health and well being.

It is recommended: for impacted wisdom teeth that pose a high risk to the lower alveolar nerve damage. See a board certified oral surgeon for assessment. Good luck!

Coronectomy: He is describing only removing the crown of the tooth - coronectomy. It is a procedure that decreases risk to nerve. Downside is if remaining portion becomes infected or later erupts, will have to be taken out secondarily.