In August of 2019, Greta Thunberg, a young climate change activist from Sweden, set sail on a zero-emissions boat from the United Kingdom to the United States to speak at the United Nations (UN) Climate Action Summit. Powered by wind, solar panels, and underwater turbines, Thunberg’s boat did not create any pollution, unlike planes—one of the largest sources of carbon emissions—which Thunberg abstains from using for travel. Thunberg researched different transportation methods to find the most Earth-friendly way to get from Europe to America. Her efforts to travel in ways that minimize her carbon footprint have increased public awareness of how modern transportation affects climate change.

How Does Transportation Impact Climate?

In many ways, climate change and modern transportation go hand in hand. The life-changing technological advances from the Industrial Revolution that ushered in new modes of travel are the same technologies that have contributed to the wide-scale pollution of the planet. As machinery began to replace manual labor in the latter half of the eighteenth century, the use of fossil fuels, such as coal and oil, for power increased. Exciting new transportation vehicles, like cars and steam-powered trains and boats, were also powered by fossil fuels, which release large quantities of carbon dioxide into the air when burned. These growing levels of carbon dioxide have generated a significant greenhouse effect, which has caused the planet to warm at a much more rapid pace—and to higher temperatures—than pre-Industrial Revolution rates, thus leading to the changes in climate seen in the twenty-first century.

In 2017, the U.S. transportation sector generated the largest percentage of greenhouse gases emitted in the United States at 29 percent. Globally, transportation accounts for between 15 and 20 percent of emissions each year. Motor vehicles are the leading cause of air pollution in the United States, though other modes of travel, such as planes and cruise ships, create greater emissions per voyage per person. 

What Large-Scale Changes Can Be Implemented to Make Transportation Greener?

Those concerned about climate change are taking steps to mitigate the effects of transportation on Earth’s atmosphere. Car manufacturers are developing and promoting electric vehicles, and scientists are exploring alternative fuels like hydrogen fuel cells. Created from renewable energy sources, these fuel cells would help end dependence on fossil fuels. High-speed railways with trains powered by electricity are another eco-friendly option that would emit less carbon dioxide than traditional diesel trains and would offer reasonable travel alternatives for airline consumers. Some countries, such as England, are considering instituting a “frequent flyer levy,” which would progressively increase an individual’s taxes on flights taken in the same year. This would hopefully reduce the overall number of flights taken each year, while not unfairly penalizing those who only fly once or twice annually.

What Can Individuals Do? 

For individuals, the first step in reducing emissions is researching the travel options available and investigating one’s relative carbon footprint. There are several online calculators that can estimate the emissions of a trip based on the mode of transportation. For short distances, walking or riding a bike is the obvious choice for low-to-no carbon emissions. Public transportation like buses, subways, and trolleys are almost always better than driving a car, because the more people traveling in a vehicle, the smaller the carbon footprint of each person. 

When traveling over longer distances, taking to the rails is typically the best course of action. In nearly all circumstances, trains have considerably lower emissions than planes, especially if the train is electric. (Diesel trains can have emissions twice as high as electric trains.) Taking a full train versus an empty one also lowers one’s carbon footprint, so traveling during peak times is the better option. For similar reasons, taking a long-distance bus ride is another lower-emission option, because of the number of people who make the trip together. 

While cars have greater emissions than trains and buses, they are still usually a better choice than flying, especially when carpooling, or driving with multiple people in the car. Replacing short flights with a car or train trip is more Earth-friendly, because taking off in a plane uses more fuel than cruising and it accounts for a larger portion of the trip for a short flight. In addition to buying an electric or hybrid car, routine car maintenance to keep the car as fuel-efficient as possible—for instance, keeping tires properly inflated—can go a long way in lowering emissions over time. 

If flying is the only option, there are some general rules for decreasing one’s carbon footprint, though emissions vary widely between airlines. Taking large commercial airliners, which seat more people and therefore have lower carbon emissions per person, instead of smaller planes like private jets, is an oft-mentioned idea for combating greenhouse gas emissions. As with other methods of transportation, traveling on a full plane also helps to lower overall emissions.

Boats vary widely with regards to their carbon emissions. Smaller boats can be modified to be low or no-emission, while cruise ships rival planes with their sizeable carbon footprint. Still, you could always use a zero-emission sailboat to travel and see the world, Greta Thunberg-style!


carbon dioxide

greenhouse gas produced by animals during respiration and used by plants during photosynthesis. Carbon dioxide is also the byproduct of burning fossil fuels.

carbon dioxide emission

quantity of carbon dioxide added to the atmosphere by human activities, such as fossil fuel combustion.

carbon emission

carbon compound (such as carbon dioxide) released into the atmosphere, often through human activity such as the burning of fossil fuels such as coal or gas.


gradual changes in all the interconnected weather elements on our planet.


discharge or release.

fossil fuel

coal, oil, or natural gas. Fossil fuels formed from the remains of ancient plants and animals.

Industrial Revolution

change in economic and social activities, beginning in the 18th century, brought by the replacement of hand tools with machinery and mass production.

public transportation

methods of movement that are available to all community members for a fee, and which follow a fixed route and schedule: buses, subways, trains and ferries.

renewable energy

energy obtained from sources that are virtually inexhaustible and replenish naturally over small time scales relative to the human life span.

SO2 emission

sulfur dioxide gas released into the atmosphere either naturally, such as by a volcano, or by people, such as factories.


movement of people or goods from one place to another.