I wasn&#x27;t convinced by this bit:<p>&gt; When I first heard this I was surprised. Can’t we just aim to cut carbon emissions in half? I asked many scientists. But they all agreed that wouldn’t be enough. The problem is that CO2 lingers in the atmosphere for decades. Even if we halted carbon emissions tomorrow, the temperature would still rise because of the carbon that’s already been released. No, we need to get all the way down to zero.<p>So if we can only reduce them by 99%, we shouldn&#x27;t even bother?<p>It seems to me that the closer we get to zero, the more expensive the next 1% will be.  At some point, it&#x27;s not worth the cost to keep going, and we&#x27;d be better off looking for ways to remove some of the CO2 that&#x27;s in the atmosphere instead of just reducing how much we&#x27;re pumping in.  His equation notably omits that possibility.