Just be careful about what kind of train you select

NEW UNIVERSITY RULES ENCOURAGE SCIENTISTS TO AVOID AIR TRAVEL

Wired, 7-3-18

...Depending on the fuel and other considerations, planes might emit from double to six times the amount of carbon dioxide per kilometer traveled per passenger compared to trains; the ratios are even higher when it comes to other climate consequences from flights, like aerosols.

...This January, both the University of California, Los Angeles, and the University of Maryland announced plans to charge departments a mitigation fee for each of the thousands of business trips taken by their faculty and staff. And three weeks ago, Ghent University in Belgium banned reimbursements for plane travel to any location within a six-hour train ride, effectively prohibiting those flights...

Alternatively, the goal of some policies, like the one at UCLA, is not expressly to reduce total flights. Instead, administrators at that university seek to mitigate flight emissions through flat fees: $9 per domestic flight and $25 per international flight, taken out of the relevant department’s budget. It’s a low enough price that researchers can continue their travel-dependent work, while contributing somewhat toward carbon offsets. The fees will go toward emissions-reducing projects on the UCLA campus, such as energy retrofitting or solar panels—although the energy savings are unlikely to fully offset flights’ carbon emissions. UCLA’s Renee Fortier and David Karwaski, both instrumental in implementing the policy, predict the fees will add up to about $250,000 the first year... 

Full article at https://www.wired.com/story/climate-scientists-take-the-train