The actual takeaway from this research is that the upstream methane emissions for natural gas extraction are the big factor in whether it is better or worse tha

The actual takeaway from this research is that the upstream methane emissions for natural gas extraction are the big factor in whether it is better or worse than coal for GHG impacts. Their numbers demonstrate that even transporting it large distances with engines that leak methane, it's those upstream leaks that dominate. Luckily we're getting better and better at monitoring those leaks, hopefully this will shift gas production away from areas with high methane leakage (e.g. Russia) towards countries that pay attention to this stuff (e.g Norway) and generally incentivize industry to do better.