The NCSL Blog


By Kristen Hildreth

As states await a ruling from the U.S Court of Appeals on the Environmental Protection Agency’s Clean Power Plan, the first week of October witnessed two events on the international front regarding efforts to reduce greenhouse gas (GHG) emissions.

Coal plantThe Paris Agreement reached the necessary participation levels to enter into force while the International Civil Aviation Organization (ICAO) formally agreed to adopt the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA). Both events signal the growing attention toward addressing the emission of GHGs across the globe, and the acknowledgment of the need for international cooperation.

The Paris Agreement aims to limit global temperature rise within this century to below 2 degrees Celsius above pre-industrial levels, with an ideal pursuit of limiting the increase to 1.5 degrees Celsius. The agreement enables nations to address rising GHG emissions through a cooperative system that encourages and relies upon transparency and accountability. In reaching the goals outlined within the agreement, governments agree to strengthen their ability to address the impacts of greenhouse gas emissions, provide support to developing nations and nations vulnerable to a changing climate, and to invite non-party stakeholders, including the private sector and others, to increase their efforts in support of efforts to reduce GHG emissions.

The agreement has been formally ratified by 79 of the 191 parties that signed it, including the United States, totaling 60 percent of global GHG emissions. It will officially enter into force Nov. 4.

The second event occurred during ICAO’s 39th assembly in Montreal when the group formally adopted CORSIA.

Noting that international aviation accounts for 1.3 percent of global CO2 emissions annually, ICAO developed the plan to address the international aviation communities’ role in GHG emissions. Specifically, CORSIA implements a market-based measure intended to address annual GHG emission increases from international civil aviation, setting airlines’ GHG emissions in 2020 as the maximum amount of what carriers are allowed to release.

If airlines’ release more than the capped amount they will be required to purchase carbon-mitigating credits. CORSIA is divided into two phases—the first phase from 2021 to 2027 is voluntary, while phase two, beginning in 2028, is mandatory and runs 2035. At time of publication, 65 states, representing more than 86.5 percent of international aviation activity indicated their intent to voluntary participate in Phase 1 of CORSIA. If full compliance is achieved, the Environmental Defense Fund estimates GHG emissions would be reduced by 2.5 billion tons, or the equivalent of removing 35 million cars off the road annually for the longevity of the agreement.

Additionally, although unrelated to ICAO’s action, the U.S. Environmental Protection Agency formally determined earlier this year that aircraft emissions contribute to the type of “pollution that causes climate change, and endangers American’s health and the environment.” Such a declaration may result in additional U.S. specific regulations regarding GHG emissions from aircraft.

Kristen Hildreth is a policy associate in NCSL's National Resources and Infrastructure committee.

Email Kristen

Actions: E-mail | Permalink |

Subscribe to the NCSL Blog

Click on the RSS feed at left to add the NCSL Blog to your favorite RSS reader. 

About the NCSL Blog

This blog offers updates on the National Conference of State Legislatures' research and training, the latest on federalism and the state legislative institution, and posts about state legislators and legislative staff. The blog is edited by NCSL staff and written primarily by NCSL's experts on public policy and the state legislative institution.