Introducing Our Science and Policy Series on Greenhouse Gases
You already know that greenhouse gases—and particularly CO2 emissions—are a major driver of rising temperatures and, therefore, climate change. But just how much greenhouse gas is our planet subject to now, how dangerous is it for our climate, and what needs to be done?
These are big questions, and both the federal government and the state of Connecticut provided some useful data to help scientists and policymakers get closer to answers when they released their greenhouse gas (GHG) reports recently.
Connecticut’s latest greenhouse gas inventory—which covers 1990-2021, with only preliminary 2021 data—asserts that the state has met its relatively modest 2020 GHG reduction target, which was set in the 2008 Global Warming Solutions Act. It also documents the areas in which further reductions are most needed. According to the new report, transportation, both personal and commercial, accounts for approximately 39 percent of Connecticut’s emissions, exceeding total emissions from the next two highest sources—residential and electricity consumption—combined. Residential emissions overtook electricity for the first time in 2019, covering one-fifth of the state’s emissions overall. Home heating is the primary driver—specifically, the burning of oil, propane, and natural gas—followed by fossil fuel uses for cooking, heating water, and drying clothes.
The GHG inventory also lays out ten policy recommendations for mitigation of emissions and their impacts. These include creating better reduction targets, standards, incentives, and codes; granting regulatory authority to implement and oversee them; increasing the urban tree canopy; pursuing alternative fuels; and improving bicycle and pedestrian infrastructure.
This year’s inventory covers the aberration of two pandemic years, during which emissions dropped, then quickly rebounded. In 2019, Connecticut emitted 39.3 million metric tons of CO2 equivalent (MMTCO2e), 13.9 percent lower than the 1990 figure. In 2020, that number dropped dramatically to 32.7 MMTCO2e as travel and business were curtailed by the pandemic. Most of the reduction in GHG for 2020 and 2021 was attributed to a decrease in personal driving during the pandemic. However, the gains were short-lived. “In 2021,” the inventory reports, “with the scaling back of COVID-19 related shutdowns, emissions began to rebound to pre-pandemic levels.”
The state Department of Energy and Environmental Protection began publishing a GHG inventory in 2003 and releases a new report every one to four years. Despite the apparent good news in this year’s inventory that today’s goals were met, Connecticut is not on track to meet its commitments tomorrow—in 2030 and 2050. The latest science now says steeper reductions than those established in 2008 are necessary to avoid the most catastrophic impacts of climate change. But currently, state agencies aren’t even required to consider climate impacts when making decisions that could increase pollution.
“Achieving the necessary reductions for 2030 and beyond will require deeper, more rapid emissions reductions from the building and transportation sectors in particular, and policies to ensure those reductions are sustained,” says Charles Rothenberger, Save the Sound’s climate and energy attorney. “We must establish a framework of accountability, authority, and enforceability that includes requiring agencies to incorporate an evaluation of climate impacts in their decision-making, providing agencies with the authority to adopt policies necessary to meet our climate obligations, and ensuring that citizens have the ability to enforce the Global Warming Solutions Act when agencies fail to act.”
Connecticut is also falling behind its neighboring states, many of which have already recognized in law the need for more aggressive reductions and accountability measures. In order to take action, Save the Sound has convened the Connecticut Coalition for Climate Action, a group of environmental advocates, health experts, labor and municipal representatives, and others advocating for climate action in the state. The Coalition’s central demand is that Connecticut keep its promise to cut climate pollution and protect our future. Read more in the Connecticut Coalition for Climate Action’s press release.
On the federal level, the Environmental Protection Agency (EPA) releases an annual Inventory of U.S. Greenhouse Gas Emissions and Sinks, as required by the United Nations Framework Convention on Climate Change (UNFCCC). According to EPA’s new 1990-2021 report, total gross U.S. GHG emissions in 2021 were 6,340.2 MMTCO2e, a decrease of 2.3 percent during the 30-year period covered by the report.
Unfortunately, fluctuating numbers over time and changes in factors such as fossil fuel use, increasing clean energy, a growing population, deforestation, and changing habits during the pandemic, to name a few, can make these reports impenetrable for the average concerned citizen. With that problem in mind, we asked Johan C. Varekamp, Harold Stearns Professor in Earth Sciences, emeritus, from Wesleyan University and a member of Save the Sound’s board of trustees, to interpret the data for us. Over the coming weeks, we’ll be sharing climate posts by Dr. Varekamp written just for you, to walk you through the facts and explain what’s really happening to our climate and what the data say we need to do to secure a livable future.