The United States has a lot of old vehicles. The average age of a car on the road is 11.4 years, according to IHS Markit, and the average age of a light truck is 10.5 years. That means the average age of a vehicle on the road in the United States is about 11 years.

That's not necessarily a bad thing. But it does mean that when new technologies come along, it takes a long time for them to spread through the vehicle fleet. And that has implications for climate change.

Consider electric vehicles. Sales of electric vehicles are growing, but they're still only about 2 percent of new vehicle sales. At that rate, it will take decades for electric vehicles to make up a significant portion of the fleet.

And that's assuming that sales of electric vehicles continue to grow at their current rate. But it's not clear that will happen. Sales of electric vehicles have slowed in recent months, and there are concerns that President Trump's policies could harm the market for electric vehicles.

That means the United States is likely to have a large number of ICE vehicles on the roads for many years to come. And that's bad news for the climate. ICE vehicles are responsible for a significant amount of greenhouse gas emissions, and the longer they stay on the roads, the longer those emissions will continue.

There are things that can be done to help speed the transition to electric vehicles. The government can provide incentives for people to buy electric vehicles. And companies can continue to invest in research and development to make electric vehicles more affordable and convenient.

But even with these measures, the transition to electric vehicles is likely to take many years. And that means ICE vehicles will be on the roads for decades to come.