Multimillennial Sea-Level Commitment Associated with Global Warming

A recent study in the Proceedings of the National Academies of Science (open access article) assesses prospective sea-level rise over the course of the next 2000 years, combining paleo-reconstructions of sea-level rise and simulations from physical models focusing on the four main components that contribute to sea-level change.

Among the study’s findings:

  1. Thermal expansion yields a global mean sea-level rise of 0.38m with a homogenous increase of ocean temperature by 1C;
  2. The total contribution of all glaciers (all land ice excluding ice sheets) to sea-level rise over the next 2000 years is ~0.6m;
  3. The potential contribution of the Greenland Ice Sheet is projected to be 0.18m °C-1 up to a 1C temperature increase and 0.34m °C-1  for temperature increases between 2-4C;
  4. Simulated temperature rise over the next two millennium yields a 1.2m rise in sea level associated with melting of the Antarctic Ice Sheet;
  5. On a 2000 year time scale, the contribution of the sources outlined above will be largely independent of the projected warming path during the first century;
  6. The total sea-level commitment from all sources is 2.3m °C-1 over 2000 years. However, the melting of the Greenland Ice Sheet ultimately results in 6m of sea-level rise over the course of several ten thousand years.

This study could stimulate some good classroom discussion. Some potential questions:

  • In the context of questions of inter-generational equity, do these potential impacts substantially expand the scope of generations whose interests must be acknowledged and protected?;
  • What are the implications of projected long-term rises in sea-levels for adaptation initiatives?
  • What are the most significant sources of uncertainty associated with paleo-climatic sea level rise and temperature records?

Climate Leader Online Course

Climate Interactive invites you to join us for The Climate Leader, an online course to better understand the interconnections and pathways to addressing our complex climate challenge. Through The Climate Leader, we will share some time-tested insights developed at MIT’s business school that we will apply to taking action on climate.

The Climate Leader will be led by Climate Interactive co-directors Beth Sawin and Drew Jones who have decades of experience helping groups navigate the challenges they face using systems thinking. The first Climate Leader course will be this fall.

Whether you are top government official or working within a small community group, The Climate Leader will offer you some practical and proven approaches for:

  • navigating complex issues
  • enhancing strategy
  • drawing on your own rational brilliance
  • using your own deep intuitive instincts

The course will help you answer questions like:

  • How can I best look at the big picture, and why is that so useful?
  • How do I identify places in my work that will have the most impact?
  • How can my efforts best be amplified?
  • What are the root causes of the challenge I’m facing?

The first course will cover things like feedback loops and techniques for mapping complex economic, social, and environmental systems to identify paths forward on climate. Later courses will cover using Climate Interactive’s suite of user-friendly climate and energy simulators, such as C-ROADS, or be specific to particular audiences.

The course is free, although if you can, we’d love you to donate to support us. In return for what we provide, we expect you will use what you can to make a difference, share what you like, and give us feedback. Our strategy is: we help you, you help us, and together we will do our best to win on climate.

If this sounds useful to your work, please join us by signing up at We will be in touch with more details, as we get closer to launching the program. 



p.s. Please share with any colleagues or networks that may be interested.



Ellie Johnston

Climate Interactive

ECOWAS Energy Training Program

The ECOWAS Centre for Renewable Energy and Energy Efficiency(ECREEE), the United Nations Industrial Development Organization (UNIDO) in cooperation with the Columbia University’s School of Engineering and Applied Science (SEAS) in New York and the Engineering Department of the University of Cape Verde (UNICV) in Mindelo, São Vicente, are executing a part-time certified distance-learning programme on sustainable energy for experts from the ECOWAS region.

The first round of this programme will train ten (10) experts currently employed by utilities, regulators or independent power producers (IPPs) in the areas of renewable energy, energy efficiency and energy policy planning. The overall objective of the programme is to strengthen the long-term capabilities of these institutions and companies to design and appraise projects, integrate renewable energy and energy efficiency into their planning, execution and monitoring cycles.

Qualified and interested experts from all fifteen (15) ECOWAS countries are invited to apply. The application deadline is 31 August 2013. Further information is available at: and


Ocean Acidification & Mussel Byssus Attachment

To date, most research on the possible impacts of ocean acidification on marine organisms has focused on potential adverse impacts on secretion of calcium carbonate in species e.g. corals and echinoderms. However, a study published in the latest issue of the  journal Nature Climate Change demonstrates potential impacts on other biomaterials critical for bivalve molluscs, a group of species that provide for than $1.5 billion in revenue to the global aquaculture industry.

Mytilid mussels are competitive dominant species in many rocky shore ecosystems throughout the world. This is largely attributable to their ability to attach themselves to bare rocks with byssal threads, which are formed from collagen-like liquid precursors that polymerizes into a stiff and extensible thread. Byssal threads contain high concentrations o f a modified amino acid and histidine-metal crosslinkages that appear critical to facilitating surface adhesion and self-healing following deformation.

In the study, carbon dioxide was increased from 300 to 1,500 μatm (a pH decline from 8.0 to 7.5). Under high carbon dioxide concentrations (1,200 μatm), the study found substantial diminution of the performance of bysall performance, including a 35-10% decline in tenacity. The authors concluded that this could adversely affect community and ecosystem dynamics given the importance of mussels’ ability to securely attach themselves to rocks.

Of course, ocean acidification is not a manifestation of climate change, but rather a parallel impact of rising levels of carbon dioxide concentrations. The potential impacts of carbon dioxide emissions on an array of bio-structures may provide an additional rationale for focusing climate policymaking on reducing this discrete greenhouse source. It thus provides a good gateway for discussing the interface of efforts to reduce greenhouse gas emissions and to confront ocean acidification, as well as the appropriate regimes to address these issues, including coordination of initiatives.