As the occurrence and intensity of extreme climate phenomena increase, it may become progressively vital to adopt a more assertive strategy to address climate change, cautioned Emily A. Carter, the Gerhard R. Andlinger Professor in Energy and the Environment at Princeton University. Carter argued that simply transitioning energy sources is insufficient given the realities of climate change while presenting at the MIT Energy Initiative (MITEI) Presents: Advancing the Energy Transition seminar on the MIT campus.

“If our response is merely to manage the past — without altering our future actions — we will still face significant challenges,” she stated. Our strategy for climate change mitigation must encompass transformation, intervention, and adaptation techniques, Carter noted.

Switching to a decarbonized electricity framework is just one aspect of the solution. Increasing volumes of solar and wind power — alongside nuclear, hydropower, and geothermal sources — are gradually reshaping the energy landscape. However, Carter pointed out that new technologies are on the horizon.

“Advanced geothermal may emerge in the next few decades. Fusion will only begin to play a significant role later in this century, yet it could provide stable electricity, allowing us to phase out nuclear,” remarked Carter, who also serves as a senior strategic advisor and associate laboratory director at the Department of Energy’s Princeton Plasma Physics Laboratory.

Building on this, Carter described how this carbon-neutral electricity should be harnessed to electrify as many processes as possible. She identified the industrial sector as a pivotal area for change: “The energy transition revolves around moving away from fossil fuels. Currently, manufacturing industries rely heavily on fossil fuels. They depend on fossil-fuel-based thermal processes.” Carter emphasized that thermal energy is significantly less efficient than electricity and showcased electricity-driven alternatives that could supplant heat in production, including electrolysis, plasmas, light-emitting diodes (LEDs) for photocatalysis, and joule heating.

The transportation sector also represents a crucial domain for electrification, Carter indicated. While electric vehicles have gained popularity recently, heavy-duty transport presents more challenges for electrification. The key solution? “Carbon-neutral fuels for heavy-duty aviation and maritime transport,” she said, stressing that these fuels must integrate into the circular economy. “It’s clear that burning these fuels will produce CO₂ [carbon dioxide], and they must derive from a non-fossil source of CO₂.”

The next phase involves intervention through carbon dioxide removal, which subsequently requires methods for storage and utilization, according to Carter. “There’s substantial discussion about constructing extensive pipelines to capture CO₂— from fossil fuel-based power facilities, cement factories, steel manufacturing sites, and other industrial locations that emit CO₂— and then transporting and storing it in subterranean aquifers,” she elaborated. While offshore pipelines are significantly costlier than their land-based counterparts, they can alleviate public concerns regarding safety. Europe is focusing its efforts exclusively offshore for this reason, and a similar approach may be applicable in the United States, Carter mentioned.

Once carbon dioxide is captured, its commercial utilization could provide economic incentives to enhance sequestration, even if only a few gigatons are utilized annually, Carter noted. Through mineralization, CO₂can be transformed into carbonates, applicable in construction materials like concrete and road-paving materials.

There exists another form of intervention that Carter currently regards as a last resort: solar geoengineering, often referred to as solar radiation management or SRM. The eruption of Mount Pinatubo in the Philippines in 1991 released sulfur dioxide into the stratosphere, temporarily cooling the Earth by around 0.5 degrees Celsius for more than a year. SRM aims to replicate that cooling effect by injecting particles into the atmosphere that reflect sunlight. According to Carter, three primary strategies exist: stratospheric aerosol injection, cirrus cloud thinning (to permit more infrared radiation emitted from the Earth to escape into space), and marine cloud brightening (enhancing clouds with sea salt to reflect additional light).

“My stance is that I hope we never have to resort to this, but we should certainly comprehend the potential outcomes if someone chooses to pursue it. It’s a matter of global security,” affirmed Carter. “In principle, its technological execution is not overly challenging, hence we should endeavor to fully understand and predict the implications of its realization.”

With any technology, engaging stakeholders and local communities is crucial for implementation, Carter advised. She underscored the necessity of respectfully addressing concerns and providing thorough answers, asserting, “We need to supply sufficient information to ease their anxieties. Gaining the trust of the public is imperative before any deployment can be contemplated.”

A fundamental aspect of establishing this trust lies in the scientific community’s responsibility to maintain transparency and critically evaluate one another’s work, Carter noted. “Skepticism is constructive. You should have to demonstrate your proof of principle.”