We recognize that there are competing demands relating to scientific collaboration and a shared concern about global climate change. One option to mitigate some of the effects of meeting together, which has been suggested by a number of members of our community, is the purchase of carbon offsets. Attendees at Exoplanets IV may wish to look into such options and consider voluntarily purchasing carbon offsets for their travel. Two sites that were recommended to the organizers are:

• Cool Effect
• Sustainable Travel International