Since the start of the program, RGGI member states have seen a GHG reduction 16% deeper than that of non-RGGI states during the same period.1 The potential emission reductions for Maryland from the RGGI program in 2020 are estimated to be 3.60 MMtCO2e. According to EPA's most recent social cost of carbon calculations (updated July 2015), this translates to an avoided cost of approximately $176 million in that year.2, 3 Assuming persistence of the program, the avoided emissions, and therefore savings would continue to accumulate in subsequent years. The social cost of carbon metric is intended to encompass a variety of damages due to climate change, including human health costs; however, as the IPCC fifth assessment report notes, there are limits to economic assessments of climate change risks based on an incomplete accounting and a number of assumptions involved in these and most models.4 Therefore, while cost-benefit analyses of climate impacts are useful, they should not be employed as a stand-alone evaluation of mitigation efforts.
Maryland's current environment has evolved based on the conditions of a climate which had until recently been changing very slowly in the years since the last ice age. Relatively rapid changes can only be tolerated within a certain range, often referred to as the system's resiliency. Once this threshold is passed, the impacts are far more pervasive and likely irreversible. It is, therefore, crucial to take steps such as the RGGI program which reduce CO2 emissions and limit the extent of climate change, in addition to implementing adaptation strategies which increase our resiliency.
Some of the environmental benefits from reduced emissions will be measurable in the form of avoided damages and costs expected to permeate various sectors of Maryland's economy. Agriculture, fisheries, energy and certain types of tourism are all impacted by temperature and precipitation patterns, and therefore, are expected to be at high risk from climate change. Other damages to the environment, such as those at the ecosystem level or to the intrinsic value of nature, are inherently more difficult to quantify, though perhaps the most obvious and visible risks are those posed to the Chesapeake Bay. The Bay ecosystem is an invaluable and iconic part of Maryland and substantial time and effort has been dedicated to its protection and restoration. Some examples of risks to various sectors and segments of Maryland are highlighted below.
1800 Washington Boulevard, Baltimore, MD 21230