High-AltitudeSolidParticleInjection(HASPI)

Why It Matters

The urgency of climate change demands a range of potential interventions, including those that might have fewer side effects than current proposals, given the risk of unforeseen atmospheric chemistry changes. HASPI could provide a more environmentally benign and potentially more efficient method of solar radiation management, reducing the risks associated with stratospheric ozone depletion or acid rain from sulfur injections. Industries involved in advanced materials manufacturing and aerospace for delivery systems would see growth, while regions reliant on specific atmospheric conditions for agriculture might face uncertainty. Key barriers include the extremely high cost of producing and deploying vast quantities of novel solid particles, ensuring their non-toxicity, and preventing aggregation or unintended atmospheric reactions. Realistic small-scale testing of HASPI materials could begin in the 2030s, with potential large-scale consideration post-2060, contingent on extensive safety research. Funding bodies like the National Science Foundation (US) and European research councils support basic research into alternative aerosols. A second-order consequence could be changes in atmospheric optical phenomena, potentially leading to more vibrant sunsets but also impacting astronomical observations or satellite communications.