Climate

In the February 11 issue of Nature Sustainability, a multi institution team unveiled a new tool for understanding and controlling the health and climate impacts of shipping goods a source not only of greenhouse gases but of soot and smog threatening our health.

In the journal, Hertz Fellow Tami Bond (’95), Professor of Civil Engineering at the University of Illinois, and her team present an extensive computational model of the environmental impact of the American shipping industry. Unprecedented in its complexity, the model connects everything from the chemical intricacies of diesel exhaust to the geography and economics of our truck-dependent shipping infrastructure.

Policies include a carbon tax

Using the model to predict the warming and health impacts of American freight over the next 30 years; so the team point to three policies which, applied over the coming decades; hence could save up to 4,000 lives per year and cut the warming contributions of our shipping by a quarter. The policies include a carbon tax ramping up to $100/ton over the next 30 years; so compliance with existing maintenance regulations, and more compact urban development.

The results show that existing efficiency regulations will save up to 3,000 lives per year by 2050; so perfect compliance could save up to 1,000 more. The carbon tax, provides the vast majority of climate benefits; so reducing both long and short term warming by nearly a quarter by itself. According to Bond, the study provides not only useful predictions; hence of the impacts of these three policies; but also a model that can be adapt and reuse to inform other policy choices.

They design this so it be easy to run many more scenarios, she said. “This way if people wanted to change things or explore assumptions; so they’ve add the flexibility to do this. This soot which they call black carbon absorbs sunlight very effectively, trapping its heat in our atmosphere; so it’s a significant contributor to Earth’s warming, especially in the year after it’s emitted.

And in the United States, a lot of this soot is coming from transportation more specifically, diesel engines, because they make more black carbon compared to gasoline engines. Especially in the United States, where they don’t have much passenger diesel, most of the diesel engines are used in freight. Policies that reduce freight activity will help both the long-term warming of CO2 and the short-term warming of black carbon.

Fuel efficient mode

Our model considers decisions like this, which matter a lot. They also capture the complex effect of a carbon tax on rail traffic – rail activity would increase if people move to a more fuel efficient mode of transportation but decrease as they ship less coal and petroleum products. But there’s also a warning: many improvements don’t happen because the infrastructure wasn’t in place.

Part of my role as an environmental researcher now is to help figure out two kinds of constraints. First, there’s the personal level: I look at what kinds of stoves or engines or transportation service people need, and how they decide what to use. And then I look at the global or societal level, considering things like how quickly we need to reduce emissions to protect human health and welfare.

Then the role of an engineer is to design for all of those constraints. And they’re very good at that; so we should be able to handle adding on something like reducing emissions. But that may need you to think more creatively rather than just making combustion more efficient, you may need to completely rethink how you’re providing energy.

The first thing we need to do is have a national conversation about how to make these big changes changes that require new infrastructure, projects that last beyond one election cycle. And second, we need to vote for people who aren’t afraid to think big. We need people who can start these projects, and see them through, within the system we have.