CO2NOW.org is a neat resource specializing in helping humans simply know how much CO2 is currently in the Earth’s atmosphere. It kind of reminds me of a thermostat. We should all have a carbon-o-stat for our earth. And it should be set for 350 PPM or lower. :(
Check out http://co2now.org/Current-CO2/CO2-Widget/ to find an assortment of widgets that you too can post on your website. Yes, they have a WordPress widget.