@article{DRED21,
  author =      { Henri F. Drake and Ronald L. Rivest and Alan Edelman and John Deutch },
  title =       { A simple model for assessing climate control trade-offs and
                  responding to unanticipated climate outcomes },
  journal =     { Environmental Research Letters },
  volume =      { 16 },
  number =      { 10 },
  date =        { 2021-09-21 },
  OPTmonth =    { September 9, },
  OPTyear =     { 2021 },
  publisher =   { {IOP} },
  url =         { https://iopscience.iop.org/article/10.1088/1748-9326/ac243e },
  abstract = {
    Persistent greenhouse gas (GHG) emissions threaten global climate goals and have prompted
    consideration of climate controls supplementary to emissions mitigation. We present MARGO, an
    idealized model of optimally-controlled climate change, which is complementary to both simpler
    conceptual models and more complicated Integrated Assessment Models. The four methods of
    controlling climate damage—mitigation, carbon dioxide removal (CDR), adaptation, and solar
    radiation modification (SRM)—are not interchangeable, as they enter at different stages of the
    causal chain that connects GHG emissions to climate damages. Early and aggressive mitigation is
    necessary to stabilize GHG concentrations below a tolerable level. While the most cost-beneficial
    and cost-effective pathways to reducing climate suffering include deployments of all four controls,
    the quantitative trade-offs between the different controls are sensitive to value-driven parameters
    and poorly-known future costs and damages.
    Static policy optimization assumes perfect foresight and obscures the active role
    decision-makers have in shaping a climate trajectory. We propose an explicit policy response
    process wherein climate control policies are re-adjusted over time in response to unanticipated
    outcomes. We illustrate this process in two ‘storyline’ scenarios: (a) near-term increases in
    mitigation and CDR are deficient, such that climate goals are expected to slip out of reach; (b) SRM
    is abruptly terminated after 40 years of successful deployment, causing an extremely rapid warming
    which is amplified by an excess of GHGs due to deterred mitigation. In both cases, an optimized
    policy response yields substantial benefits relative to continuing the original policy.
    The MARGO model is intentionally designed to be as simple, transparent, customizable, and
    accessible as possible, addressing concerns about previous climate-economic modelling approaches
    and enabling a more diverse set of stakeholders to engage with these essential and timely topics.
  }
}