Environmental Protection Agency Administrator Lisa Jackson will step down after the president’s January State of the Union speech, the agency said Thursday.

Jackson thanked President Obama for having placed her in the post four years ago and said she leaves the EPA “confident the ship is sailing in the right direction.”

It is not uncommon for agencies to change leadership when new presidential terms begin. Jackson said she is “ready in my own life for new challenges, time with my family and new opportunities to make a difference.”

In a statement, she recalled the goal she set at the beginning of her tenure to focus on climate change, but not to ignore other issues such as air pollution, toxic chemicals and waste site clean-up issues.