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Electricity

The most promising solutions in the electrical sector are something we already have: renewable energy technologies, mainly wind and solar power. Between 2010 and 2020 alone, the cost of solar-powered energy fell 85%, and the cost of wind energy fell by about half, according to the UN.

Wind and solar power use also increased tenfold during this time, accounting for 1% of total electricity production globally a decade ago, compared with 10% in 2021.

Increasing capacity to meet higher demand will be a big lift, Keller said. But it’s already underway in the US, thanks to declining costs and the recently passed Inflation Reduction Act, which heavily funds the acceleration of clean energy and the decarbonization of energy systems.

There are suddenly many tax incentives to drive the market toward this, and experts like Keller expect to see a huge increase on the employment side for wind, solar and renewables.

Switching to renewables can also build resilience in communities hurt by climate change. For instance, when Babcock Ranch in southwest Florida—which bills itself as America’s first sustainable solar powered town—was hit by Hurricane Ian in September, residents’ lights stayed on, thanks to their 700,000-panel grid and underground utility lines.

Emerging countries can also benefit. In regions just beginning to build their electricity infrastructure, planners can move straight to renewables rather than having to adapt a system based on fossil fuels.

These countries can also capitalize on their natural resources and evolve into energy-exporting countries. Keller noted that the MENA region (Middle East and North Africa) has a lot of sun, and Chile and Patagonia have an abundance of wind. As about 6 billion people depend on importing fossil fuels from other countries, according to the UN, this diversification of global energy exporters can not only help meet demand but also stabilize economies and relations between nations.

Transportation

In car-dependent countries, reducing carbon emissions from commuter traffic represents a key challenge. According to the US Department of Transportation, transportation is the second largest source of total US greenhouse gas emissions, with gasoline and diesel-fueled vehicles accounting for about two-thirds of those emissions.

Public transportation like buses and trains moves people through cities more efficiently, reducing greenhouse gas emissions even when not at full capacity. Compared with private car use, public transit contributes only about half as much carbon to the atmosphere, and US estimates show that it saves 37 million metric tons of carbon dioxide annually.

Besides investing more in public transportation, electric vehicles—whether electric cars or e-bikes—will be key to cutting emissions. Cost, however, soon won’t be as much of a problem.

Upwards of 130 million electric bicycles are expected to be sold worldwide between 2020 and 2023, with countries around the world now offering generous subsidies for residents to purchase them. 

The technology is advancing at such a rapid speed that electric cars are expected to  become cheaper than vehicles with combustion engines.

The Inflation Reduction Act also aims to entice battery manufacturers back to the US and increase domestic vehicle production—all moves that could bring costs down and speed up development worldwide. For diesel engines and long-distance transportation, researchers at universities, companies and labs across the country (like NREL) are working to turn them from fossil fuel machines into hydrogen engines.

But how will alternative fuels be transported? And how will the materials for creating all these batteries be sustainably sourced? There are still many details to figure out.

Answers to these questions and many more are being researched at NREL, as well as other national and international labs, institutes and academic collaborations. 

The ASPIRE Engineering Research Center (Advancing Sustainability through Powered Infrastructure for Roadway Electrification) is one of them. 

Led by Utah State University (with partner institutions including CU Boulder, and researchers from Colorado State University, University of Colorado Colorado Springs and NREL), ASPIRE is exploring a diverse range of transportation questions. These include: How to electrify highways that can charge vehicles on the go; data security of and best placement for charging stations; and how to build the necessary workforce of engineers, policymakers, teachers, lawyers and collaborators in related fields.

Buildings

The great indoors—or rather, where people around the world spend most of their modern lives—accounts for 230 billion square meters of building space globally, and billions more square meters could be added this decade. So what about all the carbon-intensive materials and emissions involved in construction?

Wil Srubar III, associate professor in Civil, Environmental and Architectural Engineering and CU Boulder’s Materials Science and Engineering Program, is working to transform a notoriously polluting construction staple into a carbon-neutral and carbon-negative material: He’s developed concrete made out of limestone grown by algae and bricks that are part bacteria themselves.

“We see a world in which using concrete as we know it is a mechanism to heal the planet,” Srubar said. “We have the tools and the technology to do this today.” 

Buildings are also, in general, becoming more efficient, with some state-of-the-art homes run completely on renewable energy.

A key question is whether innovation can keep up with increasing demand. 

Industry

Mining, steel production and chemical manufacturing are some of the trickier sectors in which to reduce carbon emissions. Industry is directly responsible for more than 20% of all heat-trapping emissions, according to the IPCC. Heavy industry, including mining, shipbuilding and the aircraft industry, presents some of the biggest challenges. But a few companies are leading the way.

For example, mining giant Fortescue Metals announced plans in September to eliminate the use of fossil fuels from its iron ore operations by 2030, saying it will invest more than $9 billion building batteries and greening its fleet of machinery, vehicles and trains. And last year, Anglo-Australian mining company Rio Tinto proposed a $7.5 billion plan to cut its carbon emissions by half by 2030.

Alternative materials with lower emissions could also soon come to replace plastics and some metals, while waste could be reclaimed to help create a circular economy. Refrigerants—potent greenhouse gases that often leak during use or disposal—can also be better managed and disposed of. Machines can be electrified, and energy efficiency can be increased.

“Our lives are built around using energy,” said Lisa Dilling, professor of environmental studies at CU Boulder and fellow at the Cooperative Institute for Research in Environmental Sciences (CIRES), after the release of the IPCC report on climate change mitigation in April 2022. “But we have all these other options now that are cost effective. We don’t have to get it out of the ground anymore.” 

While the dirty, carbon-producing energy source of coal still accounts for almost one-third of energy use—the single largest share of global capacity—and new coal plants are still being built in some parts of the world, the speed at which new coal is being added to the grid is slowing down.

“There is still a lot of work ahead of us,” Keller said. “But there is a new kind of excitement in this decarbonization effort which I have never seen before.”