My first solo trip took me to the high Himalayas of Spiti; I was on a sabbatical from my corporate job, and spent a month volunteer traveling, helping the local organisation Spiti Ecosphere set up a «monk for a month» program for travellers.
In the case of both asteroid impact prevention and reduction of CO2 emissions, there are vast positive ancillary effects: leaps in scientific knowledge in the first, cleaning up the ecosphere in the second.