Maryland Code, Environment § 2-1204.3

(a) The Governor may include the State as a full participant in any regional governmental initiative, agreement, or compact that limits or reduces greenhouse gas emissions from the transportation sector.

(b) On or before November 1, 2019, and each year thereafter for the next 3 years, the Department and the Department of Transportation shall report to the General Assembly, in accordance with § 2-1257 of the State Government Article, on the status of a regional governmental initiative, agreement, or compact that limits or reduces greenhouse gas emissions from the transportation sector, including:

(c) The State may withdraw from a regional governmental initiative, agreement, or compact entered into under this section if the General Assembly enacts a law to approve the withdrawal.