&gt; <i>I was sort of trying to get at this with:</i><p>&gt; <i>&gt;&gt; Health issues in cities are irrelevant if global warming means the cities are underwater.</i><p>which isn&#x27;t true. Moreover, you didn&#x27;t really give an argument for why this shouldn&#x27;t be tackled at both ends of the problem. The smell is the least of our worries with particulate emissions.