So we don&#x27;t need to worry about climate change then?<p><a href="http:&#x2F;&#x2F;www.pnas.org&#x2F;content&#x2F;105&#x2F;Supplement_1&#x2F;11543&#x2F;F2.large.jpg" rel="nofollow">http:&#x2F;&#x2F;www.pnas.org&#x2F;content&#x2F;105&#x2F;Supplement_1&#x2F;11543&#x2F;F2.large....</a><p>Cows produce methane. Here is methane breakdown of U.S. <a href="http:&#x2F;&#x2F;www3.epa.gov&#x2F;climatechange&#x2F;ghgemissions&#x2F;gases&#x2F;ch4.html" rel="nofollow">http:&#x2F;&#x2F;www3.epa.gov&#x2F;climatechange&#x2F;ghgemissions&#x2F;gases&#x2F;ch4.htm...</a><p>Cars produce mostly CO2, here&#x27;s breakdown: <a href="http:&#x2F;&#x2F;www3.epa.gov&#x2F;climatechange&#x2F;ghgemissions&#x2F;gases&#x2F;co2.html" rel="nofollow">http:&#x2F;&#x2F;www3.epa.gov&#x2F;climatechange&#x2F;ghgemissions&#x2F;gases&#x2F;co2.htm...</a><p>That &quot;Cow farts cause climate change as much as cars&quot; stuff is PETA propaganda. I&#x27;ve seen as high as &quot;52% of all carbon emissions result from meat consumption&quot;. Then I read the actual paper and &quot;We are double counting all these numbers because of moral hazard of eating meat. Lying is OK if you do it for good cause.&quot;<p>The 18% share was calculated by combining the direct effect of methane, then counting in some estimation of deforestation. It is true that Amazon rain forests end up as pasture, but that&#x27;s not necessarily the biggest reason why they cut down the forest. They first try to grow some plants on it, but as the fertility goes down it&#x27;s only good as pasture anymore. If you want to go from 18% to 8% you only need to stop <i>increasing</i> meat consumption. But that doesn&#x27;t necessarily work if the driver of deforestation turns out to be something else.