"Christian ethics" is a broad enough concept that you will likely find a plethora of answers that exist upon an immense spectrum. One may think of christian ethics as ethics that fall within the supposed teachings of the Nazarene, and as such, will focus on notions of love, hospitality, graciousness, acceptance, and prioritizing the wellbeing of others over wealth. While there are certainly groups such as Christian anarchists who tend to fall within this spectrum of ethics, who practice radical solidarity through projects and groups such as Catholic worker houses that open their doors to houseless folks and refugees, reject states, business, and borders, and who have been a part of disrupting harmful corporate and state infrastructures, these groups tend to be outliers among Christians. Christian "ethics", however, have a much larger history and current context of perpetuating oppression and harm. Particularly within a global context, Christians have enacted genocide and forced displacement of other people through crusades and witch hunts. Christian missionaries have been active in the genocide and oppression of indigenous people around the world, as is the case in the Americas, Africa, India, the Philippines, etc. Along with these missionaries often come militaries, ultimatums, land theft, and cultural death. Even among liberal Christians, Christians hold beliefs that fundamentally state that non-Christians will spend eternity in damnation and torture. This belief translates widely and pervasively into the behaviors, teachings, and actions of Christians around the world.
In contrast, "world ethics" tend to be more rooted in non-homogenous perspectives, beliefs, and methods of navigating the world and the life within the world. Within hold a world-based ethics, one tends to acknowledge the immense diversity of thoughts, beliefs, ethics, cultures, and ways of interacting within the world that exists across our planet. Rather than holding a "one way" answer, world ethics seeks to understand life from a variety of perspectives and beliefs. Christian anarchists and universalist unitarians tend to hold perspectives that are much more rooted in a world ethics.