U.S. States & Regions
States and regions across the country are adopting climate policies, including the development of regional greenhouse gas reduction markets, the creation of state and local climate action and adaptation plans, and increasing renewable energy generation. Read More

Reducing Greenhouse Gas Emissions from U.S. Transportation
![]() | January 2011 By: David L. Greene and Steven E. Plotkin Download this paper (pdf) Project Director: Judi Greenwald Project Manager: Nick Nigro |
Executive Summary:
This report examines the prospects for substantially reducing the greenhouse gas (GHG) emissions from the U.S. transportation sector, which accounts for 27 percent of the GHG emissions of the entire U.S. economy and 30 percent of the world’s transportation GHG emissions. Without shifts in existing policies, the U.S. transportation sector’s GHG emissions are expected to grow by about 10 percent by 2035, and will still account for a quarter of global transportation emissions at that time. If there is to be any hope that damages from climate change can be held to moderate levels, these trends must change.
This report shows that through a combination of policies and improved technologies, these trends can be changed. It is possible to cut GHG emissions from the transportation sector cost-effectively by up to 65 percent below 2010 levels by 2050 by improving vehicle efficiency, shifting to less carbon intensive fuels, changing travel behavior, and operating more efficiently. A major co-benefit of reducing transportation’s GHG emissions is the resulting reductions in oil use and improvements in energy security.
It develops three scenarios that diverge from “business as usual,” based on the assumption that the United States is willing to change the incentives and regulations that affect the design of vehicles, the types of fuels that are used, the choices made by individuals and businesses in purchasing and using vehicles, and how communities and their transportation infrastructure are built and used.
This report is an update of the Center's 2003 report on Reducing Greenhouse Gas Emissions From U.S. Transportation
Related white papers on Transportation Reauthorization:
Primer on Federal Surface Transportation Authorization and the Highway Trust Fund
Saving Oil and Reducing Greenhouse Gas Emissions through U.S. Federal Transportation Policy
About the Authors:
David L. Greene is a Corporate Fellow of Oak Ridge National Laboratory, Senior Fellow of the Howard H. Baker, Jr. Center for Public Policy and a Research Professor of Economics at the University of Tennessee. He is an author of more than 200 publications on transportation and energy issues. Mr. Greene is an emeritus member of both the Energy and Alternative Fuels Committees of the Transportation Research Board and a lifetime National Associate of the National Academies. He received the Society of Automotive Engineers’ Barry D. McNutt Award for Excellence in Automotive Policy Analysis, the Department of Energy’s 2007 Hydrogen R&D Award, and was recognized by the Intergovernmental Panel on Climate Change for contributions to the IPCC’s receipt of the 2007 Nobel Peace Prize. He holds a B.A. from Columbia University, an M.A. from the University of Oregon, and a Ph.D. in Geography and Environmental Engineering from The Johns Hopkins University.
Steven Plotkin is a staff scientist with Argonne National Laboratory’s Center for Transportation Research, specializing in analysis of transportation energy efficiency. He has worked extensively on automobile fuel economy technology and policy as a consultant to the Department of Energy, and was a co-principal investigator on ANL’s Multi-Path Transportation Futures Study. Mr. Plotkin was a lead author on the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report Climate Change 2007: Mitigation of Climate Change and has been selected to participate on the Fifth Assessment Report. He was for 17 years a Senior Analyst and Senior Associate with the Energy Program of the Congressional Office of Technology Assessment (OTA) and prior to that he was an environmental engineer with the U.S. Environmental Protection Agency. Mr. Plotkin has a B.S. degree in Civil Engineering from Columbia University and a Master of Engineering (Aerospace) degree from Cornell University. He is the 2005 recipient of the Society of Automotive Engineers’ Barry D. McNutt Award for Excellence in Automotive Policy Analysis.
New Jersey administration plans to buy out Sandy-affected homes
On May 16, 2013, Governor Chris Christie of New Jersey revealed a plan to spend $300 million of Federal Emergency Management Agency (FEMA) funds to buy out homes in flood-prone areas affected by Hurricane Sandy in October 2012. This program will give homeowners in Central New Jersey the opportunity to move instead of rebuilding in an area that is at high risk to flood again. The plan is based on the idea that the costs of relocating homes away from flood-prone areas will be lower than the cost of continuously rebuild flood- or storm-damaged homes
Called the “Willing Seller” Plan, this program is completely voluntary. In addition, it will target neighborhoods rather than individual homes, so that the bought out land can be razed and become open space. The program is targeting nearly 1000 homes in the central coast area of Jersey and will start with around 350 homes in Sayreville, which is located in the floodplains of the Raritan River.
The timeline for this program is short. Property appraisals will begin in June, and the first round of buyouts are expected to be completed by Labor Day. The entire program is scheduled to take just one year. The New Jersey Department of Environmental Protection (DEP) will handle the purchasing and the State Office of Emergency Management (OEM) will procure funds through FEMA.
This plan is an extension of the state’s Blue Acres Floodplain Acquisitions program, a voluntary buyout program for flood-prone homes that began in 1995, but has been low on funds since 1998 because of a high demand for buyouts. In contrast, demand for New York’s post-Sandy buyout program has been lackluster as most homeowners are choosing to stay and rebuild.
For more information:
State of New Jersey: Press Release
C2ES: Extreme Weather Map
Colorado passes tax incentives to support electric vehicle adoption
On May 15, 2013, two new pieces of legislation to lower financial barriers to using plug-in electric vehicles (PEVs) were passed into law in Colorado by Governor John Hickenlooper. Financial incentives play an important role in keeping PEVs competitive in the automobile market.
House Bill 1247, called the Innovative Motor Vehicle Income Tax Credit, secures state tax credits up to $6000 for electric vehicle purchasers or lessees until 2021, which would have otherwise expired in 2015. The bill specifically covers any EV that can be recharged from external sources, including plug-in hybrids. The bill also covers vehicles that are converted into PEVs, which are eligible for a tax incentive of $7500. This law will take effect in January 2014.
House Bill 1110, called the Special Fuel Tax & Electric Vehicle Fee, establishes a flat, annual fee of $50 for the registration of each plug-in electric vehicle. Sixty percent of the fee replaces the revenue not collected from gasoline taxes and goes toward road and highway maintenance, while the other forty percent funds electric vehicle infrastructure such as charging stations. Colorado’s PEV fee as established by HB 1100 is low compared to those considered by other states, which are around $100 or calculated based on mileage and do not fund PEV infrastructure. This law will take effect in January 2014.
According to Denver Clean Cities, as of July 2012, there were almost 1,300 registered PEVs and around 70 charging public charging stations in the state. However, this number is likely to grow because Colorado is relatively generous with policies supporting electric vehicles.
According to one source, Colorado is the leading state in the region when it comes to PEV policy. A state government report card from Southwest Energy Efficiency Project (SWEEP) awarded Colorado with a grade of “A-” for its twelve policies that support electric vehicle adoption, including the two laws mentioned above. Colorado does not fare quite as well as California, however, which would earn an “A+” under SWEEP’s methodology because of its major commitment to install fast-charging stations along highway corridors and for 15% of cars sold in the state by 2025 to be plug-in electric vehicles.
For more information:
C2ES: Common Concerns about EV Policy
C2ES: PEV State of Play and PEV Literature Review
C2ES: Powering More Travel with Electricity Map
C2ES: PEV Dialogue
plugincars: Colorado Extends $6,000 Plug-in Vehicle Credit Through 2021
Energy Sector
These states have set standards specifying that electric utilities deliver a certain amount of electricity from renewable or alternative energy sources. Most of these requirements take the form of a "renewable portfolio standard" (RPS) or "alternative energy portfolio standard" (AEPS) which requires a certain percentage of a utility’s power plant capacity or generation to come from renewable or alternative energy sources by a given date. The standards range from modest to ambitious, and qualifying energy sources vary. Some states also include "carve-outs" (requirements that a certain percentage of the portfolio be generated from a specific energy source, such as solar power) or other incentives to encourage the development of particular resources. Although climate change may not be the prime motivation behind these standards, the use of renewable or alternative energy can deliver significant greenhouse gas reductions. Increasing a state’s use of renewable energy brings other benefits as well, including job creation, energy security, and cleaner air. While the first RPS was established in 1983, the majority of states passed or strengthened their standards after 2000. Consequently, while many of these efforts have increased the penetration of renewables; others have not been in effect long enough to do so. Many states allow utilities to comply with the RPS or AEPS through tradeable credits. While the success of state efforts to increase renewable or alternative energy production will depend in part on federal policies such as production tax credits, states have been effective in encouraging clean energy generation.
For more information on state renewable and alternative portfolio standards, please refer to our resources: Comparison of Qualifying Resources for Individual States’ RPS and AEPS and Detailed Table of State Policies (including RPS/AEPS targets, carve-outs, tiers, classes, incentives, hydropower definitions, and relevant authorities).
Please refer to our Renewable Energy Credit Tracking Systems map to see how credits verifying renewable energy generation can be tracked and traded across U.S. regions.
For more information on federal portfolio standards, please refer to our: CES Resource Page.
Some states coordinate their RPS or AEPS with an Energy Efficiency Resource Standard (EERS). Learn more about states with an EERS here.
Governor Cuomo proposes action to reduce coastal flood risk
Hurricane Sandy inflicted tremendous damage on New York’s coastal communities. The threat of more intense, more frequent storms driven by climate change has led Gov. Andrew Cuomo to propose limiting development in vulnerable locations. Just as Sandy provided a preview of future climate risks, the governor’s proposal may offer an example of one effective response.
RGGI changes help both the environment and business
The nine states in the northeast Regional Greenhouse Gas Initiative took an important step this month that will significantly reduce greenhouse gas emissions and increase funding for energy efficiency and clean energy without unduly burdening businesses or consumers. That step was to adjust their cap-and-trade program by tightening the emissions cap and increasing compliance flexibility for businesses.
RGGI releases updated Model Rule, tightening CO2 cap
After a comprehensive two-year program review, the nine Regional Greenhouse Gas Initiative (RGGI) participating states released an updated Model Rule, planning the program’s first major overhaul since its 2008 initiation.
If adopted by the states, the updated Model Rule would tighten the program’s 2014 CO2 budget, or “cap,” by 45 percent -- from 165 million to 91 million short tons (to match actual emissions from 2012). Actual emissions in RGGI states have fallen well below RGGI’s original cap due to a variety of factors including the low cost of natural gas. The new cap would decline by 2.5 percent each year from 2015 to 2020, aiming to surpass the states’ current goal of reducing CO2 emissions from the power sector 10 percent between 2009 and 2018.
Besides making adjustments to the cap, the updated Model Rule includes provisions to expand its offset program, most notably by adding a forestry protocol. This protocol was modeled after the forestry offset protocol under California’s cap-and-trade program, which emphasizes conservation and reforestation.
Other additions in the updated Model Rule include the creation of a cost containment reserve (CCR) of allowances, denominated by one short ton of CO2 per year. The creation of a CCR would provide a fixed additional supply of allowances, but would only be “triggered” and made available if allowance prices exceed predefined price levels. The CCR provisions would also simplify existing compliance flexibility measures.
Analysis of the updated Model Rule indicates that the proposed changes would result in allowance prices of approximately $4 in 2014 and $10 per allowance by 2020, compared to less than $2 in 2012. The updated program would cause average electricity bills for residents in these states to increase by less than 1 percent, but would generate $2.2 billion for investments in energy efficiency and reduce greenhouse gas emissions from the power sector by about 15 percent from current levels.
The next step is for the updated Model Rule to be formally adopted by RGGI member states through legislative or regulatory processes.
For More Information
C2ES: RGGI Page
C2ES: Benefits of RGGI
RGGI: Updated Model Rule Press Release
RGGI: Updated Model Rule Summary
RGGI: Updated Model Rule
RGGI: Home Page
Judi Greenwald's Statement on RGGI Tightening Emissions Cap
Statement of Judi Greenwald
Vice President, Technology and Innovation
Center for Climate and Energy Solutions
“We applaud today’s plan by the nine states in the northeast Regional Greenhouse Gas Initiative to adjust their cap-and-trade program by tightening the cap and increasing compliance flexibility for businesses. Combined, the adjustments would significantly reduce greenhouse gas emissions and increase available funding for clean energy without unduly burdening businesses or consumers. C2ES believes that market-based policies are the most effective and efficient means of reducing greenhouse gas emissions, and we appreciate the continued leadership of the RGGI states.”
Our RGGI Page
Our comments submitted as part of RGGI’s 2012 program review
Our statement on RGGI’s launch
Contact: Laura Rehrmann, 703-516-0621, rehrmannl@c2es.org
Maryland takes action to adapt to rising seas
To adapt to the problems caused by global climate change, Maryland Governor Martin O’Malley recently issued an executive order requiring state agencies to consider the risk of coastal flooding and sea level rise when proposing projects for new state-owned structures. The directive will come into effect after July 1, 2013, when state agencies release requirements for such facilities.
Marylanders have already lost 13 islands in the Chesapeake Bay and continue to lose 580 acres of shore per year. The state’s coastline is the fourth longest in the continental United States and is considered a “hotspot” for sea-level rise because levels are rising at an annual rate three to four times faster than in other parts of the world. According to the USGS, the shoreline has experienced an increase of 2-3.7 millimeters per year compared to a global average of less than 1 millimeter. Testimony from the Secretary of the Maryland Department of Natural Resources also shows that, in the last century, the level of the Chesapeake Bay has risen more than a foot due to the combined forces of regional land subsidence – receding land movement – and global sea level rise.
At greatest risk are an estimated 40,000 homes and 257,000 acres of land located in areas just above the high tide line. The state is also at greater risk from a 100 year flood, which scientists now predict to have a 22 percent chance of occurrence by 2030.
The executive order follows the state’s 2008 Climate Action Plan, which includes a section on "Reducing Maryland´s Vulnerability to Climate Change" and focuses on the erosion impacts from coastal storm surges. As part of the plan, the Maryland Department of Natural Resources created a CoastSmart Communities Program that provides local training, grants, and technical assistance to areas that are likely to be affected by sea level rise. The program provides users with access to an online mapping tool and has awarded more than $500,000 to coastal areas in order to adapt to climate change impacts.
Besides those in Maryland, many other U.S. state officials are taking measures to address their vulnerability to climate change. State plans range from evaluating the impacts of potential sea level rise, as does Executive Order 09-05 in Washington, to addressing concerns relating to prolonged drought and severe forest fires in Arizona’s Executive Order 2005-02.
However, many scientists believe that more state action will be needed as the Intergovernmental Panel on Climate Change’s predicts up to a two-foot global sea level rise by 2100.
For More Information
Linking emissions trading programs can advance climate policy
Despite some modest steps forward, the UN Climate Change Conference in Doha was a reminder of the slow-paced nature of international negotiations. Annual conferences like these aim to achieve international agreement on reducing the man-made emissions causing climate change, but 20 years after the launch of the U.N. climate process, global emissions continue to rise.
Progress is being made at the domestic level, however, and in many cases, the policy of choice is emissions trading. One of the major challenges going forward is linking these emerging trading systems to achieve the efficiencies of an integrated global greenhouse gas market. The European Union and Australia have announced plans to link their trading systems, and California and Quebec are working toward linking theirs.







