In Great Silence there is Great Hope (2007) [pdf]
The idea that the &quot;great filter&quot;, if there really is one, remains in our future seems to me to be extremely improbable. The fact is, we <i>already</i> have the ability, just about, to colonise space. That we haven&#x27;t yet has more to do with economic reasons than technological ones, and it&#x27;s entirely conceivable that we&#x27;ll see substantial non-Earth settlements in our lifetime.<p>Now, that isn&#x27;t to say we <i>won&#x27;t</i> nuke ourselves get turn into grey goo or something before that happens, but the point is, but we&#x27;re close enough to it that, even being pessimistic, there&#x27;s got to be a reasonable chance we&#x27;ll make it (over 0.01, say). And that&#x27;s not good enough for a great filter. Any catastrophe that happens so close to the point of becoming a multi-planetary civilisation simply wouldn&#x27;t catch enough species. There&#x27;d be too many who would make it through.