Final answer:
Greenpeace is a public interest group focused on environmental conservation, sustainability, and liberal ideology, often advocating against practices they view as harmful to the environment, such as seal hunting.
Step-by-step explanation:
Greenpeace is categorized as a public interest group. As an environmental organization established in 1971, Greenpeace has been involved in various campaigns including advocating for a ban on seal hunting, which they regarded as unsustainable and inhumane. While these campaigns are meant to protect environmental interests, they sometimes clash with the livelihoods of people in certain regions, such as those in arctic areas who rely on sealing. This tension illustrates the sometimes controversial role of environmental interest groups like Greenpeace, which operate based on principles of environmental conservation and sustainability, often promoting a more liberal ideology.
Ideological interest groups, on the other hand, are organizations promoting specific political ideologies, ranging from reactionary and conservative to liberal and radical, through advocacy and research. Controversial issues such as abortion and gun control are commonly associated with ideological interest groups, though they may also overlap with public interest groups when advocating for broader societal changes.