Narrator: Global warming may not be out of control. This is Science Today. Thanks to industry and deforestation, we're pumping more and more carbon dioxide into the atmosphere. CO2 is a greenhouse gas, and some scientists fear runaway global warming as a result. But environmental scientist Ron Amundson of the University of California, Berkeley says the news isn't all bad.

Amundson: Hopefully this is not completely a runaway problem or cycle, because there are other parts of the world that are responding to this.

Narrator: Plant growth, for example, is stimulated by increased CO2 levels -- and plants absorb CO2.

Amundson: So they may in turn provide a negative feedback in the sense that their growth rates will increase, converting some of this CO2 that we're producing back into plant material.

Narrator: Plus there are the oceans, where some minerals can absorb extra carbon dioxide.

Amundson: And then also there are biological processes in the ocean that can absorb some of the CO2.

Narrator: But Amundson says that's no reason not to reduce CO2 in the first place. For Science Today, I'm Steve Tokar.