at least liberals are tied with conservatives in this category

The research on charitable giving reflects more activity (time and money) from conservatives rather than liberals.

Now, researchers at George Mason University have found that Republicans and Democrats are "equally likely" (the title of the article) to perform "green actions". (The Dems have higher numbers, but perhaps not in a statistically significant manner.)

Here's the overview article from Tara Laskowski...

Political party affiliation has little bearing on the number of “green” actions people take, a new study by Porter Novelli and Mason's Center of Excellence in Climate Change Communication Research shows.

According to the survey of more than 11,000 American adults and nearly 1,000 of their children, Democrats and Republicans differ only slightly when it comes to taking actions to protect the environment, despite great differences in their perceptions of danger related to global warming.

While Democrats were almost twice as likely as Republicans to believe that global warming is a serious problem and a threat to all life on the planet, on average they perform only about 15 percent more “green” actions than Republicans.

For example, 65 percent of those surveyed who always vote Republican and 71 percent of those who always vote Democrat said they are actively reducing energy use in their homes....

For more information on the survey and methodology, and to see the full study, visit climatechange.gmu.edu.