The Environment and Public Works Subcommittee looked at how carbon pollution is harming the state's natural resources.
"Our oyster industry on the coast, baby oysters are having trouble fixing their shells because the ocean is more acidic. It's really a canary in the coal mine. If these oysters can't form shells, what else is going on in the ocean with the acidity so much higher from carbon pollution."
Merkley says we're also seeing climate change affecting our forests and farming.
"On our farming, look to the Klamath Basin, three of the worst drought years have occurred recently in 2001, 2010, 2013 and 2014 has no snowpack and may be among the top group of drought years and all these have occurred within a few years of each other."
The senate hearing looked at their impact of climate chagne on farming, fishing, forestry and hunting.
A Senator from Montana told the hearing the Fish and Wildlife Service in his state now must spend 40 percent of its budget fighting forest fires. That's up 13 percent from several decades ago.