<p>Exclusive: ‘The preferred policy is, of course, a carbon price,’ Dr Huw McKay says, amid slowdown in BHP action on emissions</p><ul><li><p>Get our <a href="https://www.theguardian.com/email-newsletters?CMP=cvau_sfl">breaking news email</a>, <a href="https://app.adjust.com/w4u7jx3">free app</a> or <a href="https://www.theguardian.com/australia-news/series/full-story?CMP=cvau_sfl">daily news podcast</a></p></li></ul><p>A former chief economist at mining company BHP says stronger climate pol