Most conservation organizations focus on either land conservation/management or wildlife conservation. I think most organizations themselves, at least what i’m aware of, don’t focus or give a second thought to abortion. The individuals involved probably have their own opinions and views, but financial support from the organization itself would (should) be geared toward the issue their focused on i.e. land or wildlife conservation (not sustainability issues, which might be more opinionated on “population control” etc). . I’d be wary of some of the more “activist” oriented ones like Earth First. However Audubon, Ducks Unlimited, NWF, Trout Unlimited, etc are probably fine, as would likely be local greenbelts or land trusts.
Of course Franciscans International (
franciscansinternational.org) does a lot of environmental work at the UN. It’s an organization co-ministered by several different Orders in the Franciscan family.
Also, as an aside, and speaking as someone with a degree in wildlife, I can tell you one of the best ways to support conservation is by simply buying a fishing license every year, even if you don’t fish. Hunting and fishing licenses (along with firearms/ammo sales, believe it or not) are the main sources of income for state wildlife agencies in the U.S. They don’t generally get revenue from taxes. So the money goes directly towards supporting your local state conservation agencies.