FAQs

Climate systems engineering refers to the deliberate, research-driven development of large-scale interventions to respond to climate risks. These approaches, which include sunlight reflection methods (SRM), carbon removal, and glacial interventions, aim to complement greenhouse gas emissions cuts by reducing climate change and its consequences, such as rising temperatures and sea level rise.

No. Cutting greenhouse gas emissions is essential for tackling climate change. Climate systems engineering explores additional tools that could reduce climate risks, but these should be considered alongside—rather than instead of—emissions reductions. These methods are supplements not substitutes.

The Climate Systems Engineering initiative at the University of Chicago is a multidisciplinary research effort focused on the science, technology, and public policy of large-scale climate interventions. We apply insights from systems engineering and climate science to study technologies that could help reduce the risks of accumulated greenhouse gases. Our goal is to advance understanding of the potential benefits and risks of these technologies while educating future leaders who will navigate the challenges of managing industrial civilization on a warming planet.

Sunlight reflection methods (SRM) refer to techniques designed to reflect a small fraction of sunlight back into space, cooling the planet and offsetting some of the effects of climate change. These methods are sometimes referred to as solar radiation management, solar radiation modification, or solar geoengineering. One proposed version of SRM involves dispersing tiny reflective particles of sulfur dioxide in the stratosphere. This method is referred to as stratospheric aerosol injection (SAI), and it is related to the cooling effect caused by human aerosol emissions into the lower atmosphere and to volcanic eruptions.

Benefits: SRM could halt or even reverse the rise in global temperatures within years, which is not plausible with emissions cuts alone. Climate models predict that SRM could lessen the intensity of heatwaves, extreme weather, and disruptions to water availability. Slowing global temperature rise could help communities most at risk from climate change, including those facing drought, sea level rise, and food insecurity.

Risks: Potential risks include unintended effects on air pollution and ozone, unequal regional climate changes, along with geopolitical tensions over its governance. Research aims to better understand these risks and explore ways to manage them.

No, SRM—SAI or otherwise—has not been deployed in any real-world scenario. Research is ongoing to understand its potential benefits, risks, and governance challenges before any real-world implementation is considered.

Traditional carbon capture and storage (CCS) is a method for decarbonization that works by capturing CO₂ from power plants and industrial sites as a way to make energy for products such as steel and cement with minimal CO2 emissions.

Carbon removal, or CDR, describes methods for removing CO2 that’s already in the atmosphere. Open-systems carbon removal methods do not include direct air capture (DAC) but do include enhancing natural carbon sinks, perhaps most importantly by accelerating weathering reactions between CO2 and alkaline minerals either in soil systems or in the ocean.

Enhanced rock weathering is a carbon removal technique that stores carbon as stable salt in soils or dissolved cells in the ocean. This technique accelerates the natural process of chemical weathering, where certain minerals found in rocks react with CO₂ in the atmosphere and lock it away in stable forms.

Even with strong emissions cuts, CO₂ already in the atmosphere will continue driving climate change. Average temperatures will stop increasing when emissions stop, but cooling will take thousands of years as greenhouse gases slowly dissipate from the atmosphere. To cool the planet in this century, humans must either remove carbon from the air or use solar geoengineering, a temporary measure that may reduce peak temperatures, extreme storms and other climatic changes.

Many open-systems approaches, such as enhanced rock weathering and ocean carbon removal, are still in early research stages and their long-term effectiveness in capturing and storing CO₂ at a meaningful scale remains uncertain. Additionally, some methods could disrupt ecosystems. For example, adding alkaline minerals to the ocean to enhance CO₂ uptake might alter marine chemistry, with unknown effects on marine life.

Key challenges include making carbon removal cost-effective, ensuring that captured CO₂ is stored permanently, and minimizing unintended environmental impacts.

Glacial interventions are research-driven efforts to slow the melt-discharge of glaciers and ice sheets into oceans, thereby reducing sea-level rise. These efforts do not address the cause of climate warming as do solar radiation management and CO₂ removal, but rather one of the primary dangers of climate change, as rising sea levels cause disruption to human economies, habitats and natural ecosystems. Approaches to protecting Earth’s existing ice inventory from present and ongoing climate warming include slowing the speed of ice discharge from land to ocean via manipulation of friction-reducing water at the base of glaciers, reducing the ocean-driven melting rate of glaciers and ice shelves that discharge directly into warm waters by creating submarine barriers to warm ocean currents, reinforcing buttresses to ice flow and iceberg-discharge, and shading ice surfaces to reflect sunlight.

The rapid loss of ice from Antarctica and Greenland is a major driver of sea-level rise, which threatens coastal cities and communities worldwide. Sea-level rise also affects natural ecosystems in estuaries and marine wetlands. This means that slowing glacial-driven sea-level rise is akin to efforts to preserve marine wetlands and other natural coastal structures that are renowned for preventing rare, but devastating, storm surges. Slowing ice loss will unconditionally help reduce these risks.

Changes to ice sheets and surrounding waters could disrupt local-polar marine ecosystems, ocean-circulation patterns, and nutrient flows that sustain fisheries and biodiversity. Additionally, many proposed techniques are still theoretical or have only been tested at small scales and their ability to meaningfully slow global sea level rise remains uncertain.

Research is still in the early stages. Much, if not all, of this early research stems from natural examples of glacier-discharge slow-down associated with natural events that occurred in the past, and which can be studied today in their aftermath. Much of the current research is highly theoretical, relying on basic glaciological and oceanographic science to predict how Earth’s ice systems will respond to both direct engineering intervention and to letting the ice evolve without intervention. Scientists are exploring the feasibility and potential risks of different techniques before any large-scale field testing or deployment.

Decisions about climate interventions involve governments, scientists, policymakers, and the public. Because these technologies have global implications, strong governance frameworks are desirable to encourage transparency, accountability, and equity in decision-making.

Public engagement is critical. Researchers, including those involved with the Climate Systems Engineering initiative (CSEi) at the University of Chicago, are working to make climate intervention research transparent and accessible, and policymakers must create forums for informed debate and decision-making.

No, the Climate Systems Engineering initiative (CSEi) does not advocate for the deployment of any specific climate engineering methods. Our role is to advance scientific understanding, assess potential risks and benefits, and explore policy frameworks to inform responsible decision-making.