Ensuring continuity for atmospheric research
Publication Name
Funding Opportunity Details
Climate change is accelerating—intensifying extreme weather, driving biodiversity loss, and threatening global food systems. Even with stronger efforts to decarbonize and remove carbon dioxide from the atmosphere, most climate models project that temperatures will exceed safe levels for decades. In response, stratospheric aerosol injection (SAI)—the introduction of aerosols into the stratosphere to reflect sunlight and cool the planet—has emerged as a theoretical option to slow near-term warming and help avoid catastrophic climate tipping points. While early modeling suggests SAI could quickly lower global temperatures, significant uncertainties remain.
One major area of uncertainty involves the feasibility and impacts of deploying SAI at lower altitudes closer to the poles (Duffey et al., 2025; Lee et al., 2021; Lee et al., 2023; Robock et al., 2008; Wheeler et al., 2025), compared to the more commonly studied high-altitude deployments in equatorial and subtropical zones. Most current models assume deployment at altitudes above 20 km—for instance, the ARISE-SAI scenario involves injections at 21.6 km across four latitudes (15°S, 15°N, 30°S, 30°N) (Richter et al., 2022). However, a fleet of aircraft capable of reaching these altitudes does not currently exist. Although there is strong confidence in the engineering feasibility of developing such aircraft, existing planes are only capable of deploying aerosols in high-latitude regions, where the tropopause—and therefore the required injection altitude—is lower (around 9-13 km) (Smith et al., 2022). This makes high-latitude/low-altitude deployment the most realistic initial pathway for SAI, should deployment be pursued in the coming decades.
Reflective’s mission is to equip the world with the data and tools needed to make timely, informed decisions about SAI. In support of that mission, this RFP seeks proposals to evaluate the impacts of a theoretical high-latitude/low-altitude SAI deployment, and to assess the tradeoffs between this approach and potential other strategies.
Although early studies suggest high-latitude/low-altitude deployment could reduce global temperatures, many critical questions remain. These include potential effects on surface climate, human health, ecosystems, and more. To determine whether SAI using existing aircraft is a viable option, we must develop a deeper understanding of these impacts—just as we have for high-altitude scenarios. This understanding will help quantify the tradeoffs between the technical feasibility of high-latitude/low-altitude deployment and its potential risks and consequences, informing what we stand to gain or lose from pursuing this pathway.
