In recent years, the target of reaching “net zero” emissions by 2050 has come to the forefront of global climate politics. Net zero would see carbon emissions matched by carbon removals and should allow the planet to avoid dangerous climate change. But the recent prominence of this goal should not distract from the fact that there are many possible versions of net zero. Each of them will have different climate justice implications, and some of them could have very negative consequences for the world's poor. This article demonstrates the many ambiguities of net zero, and argues in favor of a net zero strategy in which those who can reasonably bear the burden adopt early and aggressive mitigation policies. We also argue for a net zero strategy in which countries place the lion's share of their faith in known emissions reduction approaches, rather than being heavily reliant on as-yet-unproven “negative emissions techniques.” Our overarching goal is to put net zero in its place, by providing a clear-sighted view of what net zero will achieve, and where the “net” in net zero needs to be tightened further if the world is to achieve climate justice.