Countries around the world have been discussing the need to rein in climate change for three decades, yet global greenhouse gas emissions – and global temperatures with them – keep rising.
When it seems like we’re getting nowhere, it’s useful to step back and examine the progress that has been made.
Let’s take a look at the U.S., historically the world’s largest greenhouse gas emitter. Over those three decades, the U.S. population soared by 28% and the economy, as measured by gross domestic product adjusted for inflation, more than doubled.
Yet U.S. emissions from many of the activities that produce greenhouse gases have remained about the same. Transportation is a bit up; industry a bit down. And electricity has seen its emissions drop significantly.
Overall, the U.S. is still among the countries with the highest per capita emissions. But U.S. emissions are down about 15% over the past 10 years.
Here’s how that happened:
U.S. electricity use has been rising lately with the shift toward more electrification of cars and heating and cooling and expansion of data centers, yet greenhouse gas emissions from electricity are down by almost 30% since 1995.
One of the main reasons is that Americans are using less coal and more natural gas to make electricity. Power plants can make electricity more efficiently using natural gas compared with coal, so it produces less emissions per unit of power.
Why did the U.S. start using more natural gas?
Research and technological innovation in fracking and horizontal drilling have allowed companies to extract more oil and gas at lower cost, making it cheaper to produce electricity from natural gas.
As a result, utilities have built more natural gas power plants while more coal plants have been shutting down or running less.
Because natural gas is a more efficient fuel than coal, it has been a win for the climate, even though it’s a fossil fuel.
Significant improvements in energy efficiency have also played a role. Household electricity use, per person, plateaued over the first two decades of the 2000s after rising continuously since the 1940s.
U.S. renewable electricity generation, including wind, solar and hydro power, has nearly tripled since 1995. Costs for solar and wind power have fallen so much that they are now cheaper than coal and competitive with natural gas. Fourteen states now get at least 30% of their power from solar, wind and battery storage.
Both wind and solar provide intermittent power, but there are a number of ways utilities are dealing with this. One way is to use demand management, offering lower prices for power during off-peak periods or discounts for companies that can cut their power use during high demand. Virtual power plants aggregate several kinds of distributed energy resources – solar panels on homes, batteries and even smart thermostats – to manage power supply and demand. The U.S. had an estimated 37.5 gigawatts of virtual power plants in 2024.
Another energy management method is battery storage. Battery costs have come down enough in the past few years to make utility-scale battery storage cost-effective.
In the U.S., gasoline consumption has remained roughly constant, but fuel efficiency has generally improved.
Sales of electric vehicles have been slow, however. Some of this could be due to the success of fracking: U.S. petroleum production has increased, and gasoline and diesel prices have remained relatively low.
People in other countries are switching to electric vehicles more rapidly. Chinese consumers can buy an entry-level EV for under $10,000 with the help of government subsidies, and the country leads the world in EV sales.
The construction of new data centers, in part to serve the explosive growth of artificial intelligence, is drawing a lot of attention to future energy demand. The future electricity demand growth from data centers is still unclear, though, meaning the effects of data centers on electricity rates and power system emissions are also uncertain.
The U.S. can expect growing electricity demand for industrial processes and electric vehicles, as well as the overall transition from using oil and gas for heating and appliances to using electricity that continues across the country.
Valerie Thomas is a professor of industrial engineering at Georgia Institute of Technology. Distributed by The Conversation and The Associated Press.
