Based in Australia, Carlson advises NTI leadership on international nuclear security, safeguards and verification, and management of the nuclear fuel cycle. He supports NTI's efforts in the Asia-Pacific region on nuclear security and arms reduction. He is a Visiting Fellow at the Lowy Institute, a member of the Advisory Council of the International Luxembourg Forum, and of VERTIC's International Verification Consultants Network. Carlson was an official in the Australian government for more than four decades.

Before retiring from government, he was director general of the Australian Safeguards and Nonproliferation Office. He was appointed as chairman of the Standing Advisory Group on Safeguards Implementation by former International Atomic Energy Agency (IAEA) Director General Mohammed ElBaradei and served from 2001 to 2006. He also served as Alternate Governor for Australia on the IAEA Board of Governors.

Carlson was a member of the Advisory Board of the International Commission on Nuclear Non-Proliferation and Disarmament and is founding chair of the Asia-Pacific Safeguards Network. He is a fellow of the Institute of Nuclear Materials Management and recipient of the Institute's Distinguished Service Award. He has written numerous papers and presentations on nuclear nonproliferation, disarmament and verification issues. In June 2012 Carlson was awarded the national honor of Member of the Order of Australia (AM).