Humanity faces a range of existential threats, from nuclear war to pandemics to artificial intelligence run amok. Yet despite the gravity of these threats, it can be difficult to know how best to address them. How do we prioritize among different causes, and how can we measure the effectiveness of the charities working to mitigate these risks?

One way to approach these questions is to focus on the preservation of humanity itself. At its core, the goal of existential risk reduction is to ensure that humanity has a long and flourishing future. This is important not just for our own sake, but for the sake of future generations and the many other forms of life that depend on our continued existence.

To achieve this goal, we need to identify the most effective ways to reduce the risks of catastrophic events. This is where the charities and organizations on our list come in. These groups are working to address a range of existential threats, from nuclear weapons and biotechnology to climate change and artificial intelligence.

Determining which charities to include on this list was a difficult task. Unlike many other causes, the effectiveness of existential risk reduction is notoriously difficult to measure. We can't run randomized controlled trials to see which interventions work best, nor can we point to historical data to show how past interventions have succeeded or failed.

Instead, we have to rely on a combination of expert opinion, empirical research, and theoretical analysis. We looked for organizations that are addressing the most pressing existential risks, that are led by experts in their fields, and that have a track record of success in achieving their goals.  In order to determine reputable organizations, we looked for referrals from The Future of Humanity Institute at the University of Oxford, the Global Catastrophic Risk Institute, and the Centre for the Study of Existential Risk at the University of Cambridge.

Of course, there are many other organizations and initiatives that are working to preserve humanity that we have not included on this list. Our aim is not to be exhaustive, but rather to highlight some of the most promising avenues for making a difference.  Likewise, we are unable to allocate donations based on the efficacy of each group.  Instead, we estimate their annual expenses and suggest a matching allocation.