I appreciate Sen. Mitt Romney acknowledging that the earth is warming and asking, “Do humans contribute to it?” (Tribune, Feb. 21). Fortunately, the answer has been well established by decades of scientific inquiry.

Is it a natural cycle? No, because the current temperatures have risen too fast compared past changes. Volcanoes? No, for the small amount of greenhouse gas they have emitted can’t account for the observed warming. The sun? No, because solar irradiance has declined slightly while the earth has warmed. The only explanation that fits the observations by climate scientists is the rise in human-generated greenhouse gasses.

Romney also stated, “I hope there is something we can do.” Indeed, there are many things we can do. One of the most effective things would be to pass the bipartisan bill recently introduced in the U.S House of Representatives: the Energy Innovation and Carbon Dividend Act. This would place a steadily increasing fee on fossil fuels and return all net proceeds to the pockets of Americans. It would be good for people, good for the economy, and good for the climate.

Now is the time for Romney, Sen. Mike Lee and Reps. Rob Bishop, Chris Stewart, John Curtis and Ben McAdams to support this legislation.

David Folland, Sandy