<story><title>Acidity in atmosphere minimised to preindustrial levels</title><url>http://news.ku.dk/all_news/2016/09/acidity-in-atmosphere-minimised-to-preindustrial-levels/</url></story><parent_chain></parent_chain><comment><author>tlb</author><text>My family&amp;#x27;s business in the 1970s was cleaning windows on tall buildings in Saskatoon (there were dozens). The effects of acid rain on buildings was dramatic. Facades on buildings that had stood since the 1920s were crumbling. Acid rain damage control was a whole segment of our business. Presumably the pollution there was no worse than anywhere else.&lt;p&gt;Emissions controls for vehicles and coal power plants are important. Things would be much worse without them.</text></comment>
<story><title>Acidity in atmosphere minimised to preindustrial levels</title><url>http://news.ku.dk/all_news/2016/09/acidity-in-atmosphere-minimised-to-preindustrial-levels/</url></story><parent_chain></parent_chain><comment><author>DubiousPusher</author><text>I normally love HN comment sections because really knowledgable people put these articles into greater perspective. This has not been one such section. Can someone with domain specific knowledge speak to what this means? What are the scope of the benefits? What was the danger if this hadn&amp;#x27;t been turned around?</text></comment>