HONOLULU (AP) — President Barack Obama has vetoed two bills that would have blocked steps that his administration is taking to address climate change.

One bill would have nullified carbon pollution standards set by the Environmental Protection Agency. The second bill would have voided a set of national standards designed to reduce the amount of greenhouse gas pollution from existing power plants.

In a letter notifying Congress of his decision, Obama says climate change is a “profound threat” that must be addressed.

Some Republican lawmakers and presidential candidates scoff at the climate science.

Obama has made addressing climate change a priority. He recently praised a new international climate agreement reached at a Paris conference and credited his administration as being a driving force behind the deal.