Transport Decarbonisation Alliance

The Transport Decarbonisation Alliance (TDA) was launched in 2018 as a unique collaboration to accelerate the worldwide transformation of the transport sector towards a net-zero emission mobility system before 2050.

TDA News

Caltrans News Flash #187 (VIDEO)

Paris Agreement COP24 - Katowice

Dec. 2018

At the Conference of the Parties (COP24) at the 2018 United Nations Climate Conference in Katowice, Poland, the PPMC discussed the global need for the transport sector to continue the trajectory of raising ambition on sustainable, low-carbon mobility and providing continued guidance for translating ambition into accelerated action through tested sustainable mobility solutions (PDF).

Echoing the science and discussions of the TDA, COP24 emphasized that continued efforts in the transportation sector will put the globe on track to meet Paris Agreement climate targets. While COP24 clarified that net decarbonization of the transport sector by 2050 is still attainable, it cautioned that reaching targets will require an immediate and concerted turnaround of global policy action.

The Paris Process on Mobility and Climate (PPMC), a formal body of the Paris Agreement, works to integrate the sustainable development and climate change agenda of the Paris Agreement for the transport sector. The TDA, an informal affiliate of PPMC, facilitates discussion on decarbonization in the context of global, regional, national, local and corporate policy processes; leading by example by demonstrating that decarbonization is technically feasible, economically attractive, and brings broad social and environmental benefits by sharing experiences and best practices. California became a member of the TDA in September 2018.

California and the TDA

California became the 19th Member of the Transport Decarbonisation Alliance,joining countries: Costa Rica, Finland, France, Luxembourg, Netherlands and Portugal; Cities: Rotterdam, Lisbon, Porto, Gaia and Matosinhos; and, Companies: Alstom, CEiiA, Deutsche Post DHL Group, EDP, ITAIPU Binancional, Michelin, and PTV.

As a member of the TDA, California is expected to:

  • Make a public commitment to accelerate action to decarbonise transport to meet a net-zero emissions sector as soon as possible
  • Share regular up-to-date information about their objectives, actions, progress and experiences in decarbonising transport
  • Promote strategic direction, action guidelines and tools provided by the TDA ecosystem
  • Contribute actively to the promotion of the TDA objectives (as a TDA Ambassadors)

For more information about the TDA and its Members please see:


Decarbonization is the act of reducing the transport sector’s carbon emissions through three general strategies: fuels, vehicles and travel demand.

Globally, the TDA has a goal of moving towards a net-zero emission mobility system before 2050. The transport sector accounts for about 7.5 Gt of global CO2 emissions annually.

The Paris Agreement established a goal to limit climate change warming to below 1.5 degrees Celsius by year 2050. To achieve a 1.5 degree Celsius scenario, the transport sector must decrease its 7.5 Gt of annual CO2 emissions to 2.5 Gt by 2050 through decarbonization.

California Takes Action Now

Transport has been named one of the thematic areas under the Global Climate Action Agenda (GCAA), formerly the Lima Paris Action Agenda (LPAA). The discussion on transport within the GCAA has been shaped since COP21 by the Paris Process for Mobility and Climate (PPMC). As a member of the TDA, California will work alongside international partners to take action now on decarbonization of the transport sector through three main actions:

  1. Plan for mid-long-term disruptions towards a systemic transformation of the Transport sector (2020-2050+)
    Bring together all relevant stakeholders (public and private sector, think tanks) around a sound Global Macro-Roadmap, a reference or compass to set the course towards the long-term direction set in Paris, enabling each actor to develop their own positioning and work out their contribution in line with the overall directions set by the Global Macro-Roadmap

  2. Taking the short term decisions which the success of the Paris Agreement ultimately depends on (2016-2020)
    Recommend urgent measures (Quick Wins) to public authorities and private sector stakeholders to kickstart the transformation of the Transport sector
    Contribute towards strengthening of existing nationally determined contributions and support them to push up the required ambition level in 2020, inspired by the directions set in the Global Macro-Roadmap

  3. Leveraging existing Global Climate Action Agenda (GCAA) Transport Initiatives and encouraging new ones
    Strengthen GCAA Transport Initiatives, improve their governance, and help them to scale up by linking more directly to action by parties
    Promote the emergence of new Initiatives to address those areas of action that have yet to be worked out by the transport sector

    Transport Decarbonization is Crucial in Realizing the Paris Agreement

    The TDA builds on the commitments and the stated ambition of Heads of States, Mayors and CEOs to decarbonize transport before 2050, targeting emissions from all modes of passenger and freight transport, including land transport, aviation and maritime transport. This is the first-time parties across the three key constituencies (countries/regions, cities and companies) are committing to work together in a coordinated way to catalyse the transformation of the transport sector.

    TDA Materials

    1. TDA Fact Sheet(PDF)
    2. TDA Charter(PDF) 
    3. Press Release about California joining the TDA(PDF) 
    4. TDA Work Plan(PDF)