The main cause of climate change is human activities, particularly the emission of greenhouse gases (GHGs) into the atmosphere. The Maryland Department of the Environment (MDE) is leading Governor Hogan's efforts to reduce GHG emissions while creating jobs and benefiting the economy, as required by the Greenhouse Gas Reduction Act (GGRA). Although many initiatives throughout the State contribute to these efforts, the Regional Greenhouse Gas Initiative (RGGI) and the Maryland Commission on Climate Change (chaired by MDE Secretary Ben Grumbles) are key efforts by MDE, each of which can be explored further by following the navigational links on the left-hand side of this page.
In November 2018, a federal report advised that "climate change is affecting the natural environment, agriculture, energy production and use, land and water resources, transportation, and human health and welfare across the U.S. and its territories."
With 3,100 miles of shoreline, Maryland is the fourth most vulnerable state to suffer the effects of sea-level rise associated with climate change. Rising sea levels and increased storm intensity could have devastating and far-reaching impacts on the Atlantic coast and the Chesapeake Bay ecosystem that affect the environmental, recreational and economic benefits enjoyed by Maryland and its visitors. Although Maryland's coastal areas may be considered particularly vulnerable, all areas of the State are at risk. In general, climate change alters the severity, frequency or distribution of existing issues that are impacted either directly or indirectly by temperature and precipitation. This includes, but is not limited to:
- Impacts on coastal, bay, and inland water quality parameters that may change the viable uses of surface water, such as for irrigation, recreation, or human consumption;
- More frequent disruptions to urban and coastal infrastructure in Maryland caused by extreme weather events and sea-level rise that may indirectly impact the economy of the region by restricting the flow of goods and affecting days worked;
- Common stressors experienced among ecosystems, agriculture, fisheries, and forestry such as those caused by general changes in temperature and precipitation regimes; increased extreme weather events; and increased pressures from weeds, diseases, and pests;
- Human health issues, including those affected by impacts on food and water supply, air quality and extreme weather events; and
- A higher probability of negative outcomes for disadvantaged communities and individuals inherently more sensitive or with a reduced adaptive capacity for responding to the impacts of climate change.
To learn more about climate change and what Maryland is doing to combat it, visit the
Climate Change Reports page and the news feed on the left side of this page. Also, please read about the Maryland Commission on Climate Change. From a national perspective, visit the U.S. Environmental Protection Agency (EPA) website on
Climate Change in the United States.
Maryland's Greenhouse Gas Emissions Reduction Act (GGRA)
In 2009, Maryland adopted the Greenhouse Gas Emissions Reduction Act (GGRA) and it was amended in 2016. The law requires the State to reduce GHG emissions 25 percent from a 2006 baseline by 2020, in a way that ensures a positive impact on Maryland's economy, protects existing manufacturing jobs and creates new jobs in the State. MDE's 2015 GGRA Plan update showed that Maryland was on target to not only meet but also to exceed this level of emissions reduction; with an estimated economic benefit between $2.5 and $3.5 billion in increased economic output by 2020 as well as creation and maintenance of between 26,000 and 33,000 new jobs. In 2015, Governor Hogan signed an updated version of the law, which includes the same balanced requirements and safeguards as the original, such as additional reporting and a mid-course reaffirmation of goals by the Maryland General Assembly, as well as incorporating protection for jobs and the economy. The most significant enhancement was a new benchmark requiring a 40 percent reduction of emissions from 2006 levels by 2030. This additional benchmark was included in order to ensure continued progress after 2020 toward the State's long-term GHG emission reduction goals. According to a World Resources Institute report published in August 2020, Maryland leads the nation in the amount of emissions reductions (38%) and simultaneous growth of GDP (18%) in a 12 year period.
In the fall of 2019, MDE released a comprehensive, economy-wide draft plan to dramatically reduce emissions of greenhouse gases that contribute to climate change. The draft plan will set Maryland on an ambitious path and serve as a model for how the nation can respond to climate change while also supporting economic growth.
The plan calls for a 44% reduction in greenhouse gas emissions by 2030, surpassing the 40% reduction goal required by state law. In addition to reducing emissions that contribute to climate change, following the plan also will produce better air quality by reducing emissions that contribute to ground-level ozone and fine particle pollution. It also will improve water quality through reductions in nitrogen pollution to the state’s waterways, including the Chesapeake Bay. The Maryland Department of the Environment conducted public forums throughout Maryland and online for citizens, stakeholders, and communities to comment on the draft plan. The public comment period closed as of April 21, 2020; staff is finalizing the GGRA report to submit to Governor Hogan and the State Legislature by the end of 2020.
Climate Change Program Division Chief
Maryland Department of the Environment
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