Your excellent article about the planet’s ability to absorb carbon dioxide concludes with a hope that the delegates at Copenhagen will allocate sufficient funds for further research into this important issue (“What Lies Beneath,” December 5, 2009). Indeed, the absorption capacity of plants, soils, and oceans, the three sinks of the noxious gas, will be of utmost importance in connection with climate change. If and when that capacity is surpassed, climate change will start feeding upon itself. As you point out, the amount of money needed for research into this and related issues is only a small fraction of the amount needed to avoid frightening levels of carbon dioxide ever reaching the planet’s natural sinks. I would only add one small thing to your argument: without research of the kind you report, curbing emissions will most likely be misguided, anyhow. Policy minus knowledge equals waste of resources. The money spent on research is thus essential for climate-change policy worthy of that name.