A good way to take part in increasing the number of trees, if you own your own home, is to improve the state of your shade trees. The trees absorb atmospheric carbon while also reducing home temperatures in summer, which in turn reduces the electricity people use for cooling. (And you save money!!) So a shade tree is a particularly effective way to reduce both atmospheric CO2 and electric bills. You might think of shade trees as cheap, biological solar panels.
Also, one can plant fruit trees in their yard. I put in 6 last fall and plan to put in another dozen in the next 2-3 weeks. Over the winter I added about 6 truck loads of wood chips to the yard to reduce water usage. (My general feeling at this point from working with the soil is that the wood chips reduce watering needs by at least 80% here. This is a form of xeriscaping, if you're interested.) With all this food growing in the coming years we'll be taking fewer trips to the grocery store while eating better. And probably giving away and trading a lot of food - we're already starting to trade for eggs from a friend, for example.
Also, one can plant fruit trees in their yard. I put in 6 last fall and plan to put in another dozen in the next 2-3 weeks. Over the winter I added about 6 truck loads of wood chips to the yard to reduce water usage. (My general feeling at this point from working with the soil is that the wood chips reduce watering needs by at least 80% here. This is a form of xeriscaping, if you're interested.) With all this food growing in the coming years we'll be taking fewer trips to the grocery store while eating better. And probably giving away and trading a lot of food - we're already starting to trade for eggs from a friend, for example.