Here’s a template for a letter I hope you will consider sending/emailing to all of your elected representatives at the municipal, state, and federal levels, if you are in the US. Thanks
Dear [elected official]
I am writing to ask you to join the very small but hopefully growing number of elected representatives and executives in noting the important news this week regarding the human contribution to the amount of atmospheric CO2. This week the landmark value of 400 ppm was reached, which is a significant amount more than the pre-industrial baseline level of about 280 ppm. As an elected official, it seems appropriate for you to make a public note using any of your usual outlets that this important event has occurred, in order to bring more focus to the national and regional discussion of climate change.
Here is a link to the NOAA web site giving the details:
Thank you very much,
[your name here]