With just hours left in the public comment period on the proposed construction of the Keystone XL pipeline, green groups are calling on all concerned citizens to contact the Obama administration and make their opposition known.

“Right now we are in the middle of the last official public comment period for Keystone XL — one of the very last steps before President Obama makes his decision on the pipeline, and the final opportunity to give your input (in an official way),” writes 350.org on their website, which offers a one-step form to file a comment with the State Department.

“The State Department is accepting comments on the Final Environmental Impact Statement, and the last time State was accepting comments, we submitted over 1 million as a movement—let’s see if we can beat that goal this time around,” the group writes.

The 30-day public comment period ends on March 7th, at which point Obama will be open to make his final decision.

And on Thursday night, campaigners plan to submit those comments in a less formal way: projecting them on the outside walls of the State Department building.