2021 plans for TF HTAP

We would like to wish you a happy new year and provide you with an update on the status of current and up-coming activities of the Task Force on Hemispheric Transport of Air Pollutants.  We would also like to introduce our new website (www.htap.org), hosted by the Institute of Environmental Protection – National Research Institute, Poland.  We will be posting information here about our workshops, plans, and reports, and participate in our interactive policy-science forum.  

Up-Coming Virtual Workshops for 2021

This winter/spring, we will be hosting three on-line workshops in support of TF HTAP activities. 

March 17, 2021: Reviewing Q&As for Gothenburg Protocol

April 13, 2021: Attributing Mercury Trends to Emissions

April 15, 2021: Attributing POPs Trends to Emissions


March: Gothenburg Protocol Review Questions (O3, PM)

The March workshop will focus on supporting the process of reviewing the revised Gothenburg Protocol, which addresses O3, PM, and S and N deposition. As part of the review process, the Working Group on Strategies and Review (WGSR) has posed a series of questions to the technical bodies under the LRTAP Convention.  TF HTAP has been asked to contribute to the answers to six of those questions.  The questions and draft answers to be discussed at the workshop are posted here.

We would like to promote interactive discussion during the workshop, but it will be also possible to contribute with short interventions of no more than a few slides each. Depending on the state of the discussion, we may welcome such presentations spontaneously during the meeting, but if you already feel that you could significantly contribute to the discussion through a short presentation, please let us know in advance so that we can plan the agenda accordingly. Please also let us know in advance if there are specific topics that you feel deserve special attention during the workshop so we can allocate sufficient time. We will collect your feedback until March 10, and we will provide an agenda for the workshop on March 15.

If you are unable to attend the workshop, we welcome your comments at any time during the review process. Contributions received by March 31 will help inform our first report to the Working Group on Strategies and Review.  Also, the questions and answers are being added to the “Answers to Policy-Relevant Questions” section of www.htap.org and will continue to be updated after the workshop.  We hope to continue to use this platform to refine our contributions to the Gothenburg Protocol review process as it continues into 2022.

March 17, 13:00-17:00 UTC O3 and PM

Please register here


April: Regional and Extra-regional Contribution to Hg and POPs/CEC Trends

The focus of the two April workshops will be on improving our ability to estimate the contribution of regional and extra-regional sources to long-term trends in Hg, POPs, and other chemicals of emerging concern.  In the workshops, we will:

  • Anticipate assessment needs of the LRTAP, Minamata, and Stockholm Conventions
  • Review progress made in other forums, including recent AMAP assessments. 
    • Identify cooperative activities that can be undertaken in the short term (2 years) and longer term (4-5 years) to improve our understanding and ability to estimate source contributions.

The 13 April workshop will focus on Hg, and the 15 April workshop will focus on POPs and other chemicals of emerging concern.

Follow up meetings will be scheduled to further organize cooperative activities identified in the workshops.

April 13, 11:00-15:00 UTC Hg

Please register here

April 15, 11:00-15:00 UTC, POPs/CECs

Please register here


Outcomes of 2020 TF HTAP sponsored workshop on methane and ozone

The TF HTAP sponsored workshop, held on April 22-24, 30th and April 30th, 2020, laid the foundation for the CLRTAP work plan item 1.1.4.7, namely, to organize analyses and model improvements needed to improve the estimation of the health and environmental benefits of decreasing ozone through mitigation of methane emissions.

Workshop participants identified near-term (within 2 years) opportunities and longer-term research needs to improve the scientific basis for assessing the impact of methane mitigation measures on tropospheric ozone levels at regional and global scales; and, the impact of tropospheric ozone on human health and ecosystem damage at regional and global scales.  These near- and longer-term opportunities were prioritized in accordance with the TF HTAP mandate and needs of the Convention.  Near-term opportunities included evaluating regional ozone concentration responses to global changes in methane using recent modeling results.  In addition, the Task Force invited experts to contribute analyses of trends in extra-regional contributions to the EMEP domain, the intercontinental scale impact of shipping emission controls, and comparisons of source attribution methods in order to assess our current understanding of these issues.  Finally, the Task Force identified potential areas of collaboration to be explored with other international cooperative scientific efforts, including AerChemMIP, CCMI, TOAR, and AQMEII.  A more comprehensive summary of the outcomes of this workshop will be posted onwww.htap.org along with the presentation materials.  The outcomes of this workshop informed the 2020-2021 work plan for TF HTAP.

Interactive TF HTAP Answers to Policy-Relevant Questions

TF HTAP has created an on-line forum for the policy and science communities to discuss and address policy-relevant science questions that fall within TF HTAP’s mandate.  This living document will form the basis of on-going science advice to the Working Group on Strategies and Review (WGSR) throughout the review of the revised Gothenburg Protocol and its on-going implementation. 

The living document currently contains questions and answers from previous HTAP reports discussing findings from the HTAP1 and HTAP2 analyses. In the coming weeks, we will be adding the questions posed in the context of the Gothenburg Review and taking a first stab at populating the answers to these questions with the science information that we have in-hand.  We will subsequently use this forum and the virtual workshop on March 17th to solicit your contributions to and comments on these responses.  The evolving online document will serve as the foundation for TF HTAP chairs’ reports to the LRTAP Convention, but the on-line document will remain evergreen and open to the inclusion of new policy questions and up-dated scientific responses. 

There are at least two ways that you can contribute to the online discussion. First, anyone can post a comment or suggestion about the text of a question or answer. We periodically update the text based on comments and suggestions received.  Second, if you would like to be more involved in the process of responding to comments and editing, you can contact us to arrange editing access.

HTAPv3 Mosaic Emission Inventory

Work on the next version of the HTAP global mosaic emission inventory began in early 2020. As was the case in HTAPv2, the new version will use EDGAR (currently at version 5) as a global base inventory for gap-filling, with spatially resolved regional inventories used for more local detail where available. This upcoming version will have notable improvements over the previous version (used in phase 2 of HTAP):

  • Whereas the v2 mosaic only covered two years (2008 and 2010), the v3 mosaic will cover approximately the last two decades, enabling the study of recent trends and variability in hemispheric transport.
  • Whereas the v2 mosaic specified emissions from highly aggregated sectors, the v3 mosaic will include much higher sectoral resolution, enabling more detailed sensitivity studies and the generation of more realistic emission scenarios.

The HTAPv3 mosaic is currently still under development in close cooperation with regional data providers and the JRC. We expect to deliver a first version for testing by the end of 2021. The v3 mosaic inventory will form the basis of model experiments to be designed and performed from 2022 onwards.

Contribution of Shipping to Trends in Surface Ozone

Previous studies, including some published in the joint HTAP/AQMEII/MICS special issue of ACP, have identified NOx emissions from shipping as an important ozone precursor over continental regions, especially near coastlines. This issue was discussed at the TF HTAP sponsored workshop in April 2020 (see above).  At this workshop, a small number of modelling groups expressed interest in a follow-up study from phase two of HTAP to perform a more detailed attribution of continental ozone levels to shipping emissions from the major ocean basins as well as all current and several proposed ECAs (Emission Control Areas). This work is currently ongoing and additional participants are welcome. Please contact the TF HTAP leadership team if you are interested.

We look forward to connecting with you at our virtual workshops.

Thank you for your continued interest and participation.

Terry KeatingHeather MorrisonTim Butler and Jacek Kaminski

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