While I give some to several universities, some reproductive health organizations, a bicycle advocacy group, third world health and sanitation projects, one specific medical research effort with a personal connection, and several youth development organizations, most of my giving this year will be to the American Humanist Association and related groups.
Why? There are lots of different ways to evaluate the effectiveness of charitable giving, but as I age I find myself less inclined to relieve immediate suffering and more inclined to support long term structural changes in society. And I think that the continued spread of ridiculous ancient superstitions and magical thinking to be the single greatest threat to the survival of our species. Humanity needs to abandon religion as anything but interesting cultural mythology. I am terrified by the fact that modern nation states with nuclear weapons are being run by people who seriously believe in talking animals and miraculous zombies and Armageddon-as-salvation.
As a country, as a global society, and as a species, we need to recognize that our successes have all been built on science, reason, cooperation, and effective organization for the common good. Religions have systematically undermined every one of those for thousands of years. In an age of global communications and interplanetary exploration, there can be no place for people who perform human sacrifice to control the weather, or ask chicken entrails how to run their businesses, or refer to ancient scrolls to dictate which legislation to pass.
I'm totally in support of religious customs as cultural heritage and personal identity. And most of the personal ideology is good, too. But like Zeus and Thor, all modern religions need to be firmly placed in the realm of mythology, not policy.
Magic isn't real. Using magical thinking to make decisions is dumb. Using magical thinking to control people is evil. Most religions specialize in both.
Basically every other cause I believe in is also helped by getting religion out of the way of good decision making.