Narrator: This is Science Today. Nearly all the models used to predict climate change either do not factor in agricultural regions or assume that farmers behave the same way through time. But when climate scientist David Lobell of the Lawrence Livermore National Laboratory created models that included recent changes in agricultural practices, such as more irrigation, less tillage and higher yielding crops, he found that these models predicted lower temperatures than previous ones did.
Lobell: The effects were strongest for irrigation and we found that it could actually cool locally the temperatures by up to six degrees. And so it's a very significant effect, if you talk about greenhouse warming, that's on the order of that temperature change or even bigger.
Narrator: While this may not amount to a big effect on a global scale, in agricultural areas such as California , it's a big effect.
Lobell: The key message is if we want to be able to adapt agriculture to climate change, then we're going to have to do a better job of incorporating what farmers are doing into climate models.
Narrator: For Science Today, I'm Larissa Branin .