It is common to speak about US transportation woes in terms of failing infrastructure, congested roadways, the lack of high speed rail and rising pedestrian fatalities. The ever more pressing issue of climate change moves transportation into focus for its impact on the environment.
In the US, as in many other countries, transportation has become the
largest source of greenhouse gases. Starting in 2016 the U.S. transportation sector - which includes cars, trucks, planes, trains, and boats - emitted with
1.9 billion tons of CO2 annually more greenhouse gas than the electric power sector
1.8 billions tons. Contrary to what one would expect, not trucks, trains or ships are the biggest polluters, the
vast majority of emissions come from
light duty vehicles, i.e. cars and vans. In other words, nothing would protect the environment and decrease carbon emissions more than a reduction of the US transportation footprint.
Usually a distinction is made between greenhouse gas emissions (GHG) and pollutants affecting human health. Mobile sources such as transportation are also a major contributors of pollutants affecting human health, such as particulates, sulfur and NOx. Diesel and small two stroke engines from lawn equipment are especially bad polluters, light duty vehicles have been cleaned up a good bit since lead has been removed from gasoline fuel some 50 years ago and catalytic converters have become mandatory.
Nearly one half of all Americans-an estimated 150 million-live in areas that don't meet federal air quality standards. Passenger vehicles and heavy-duty trucks are a major source of this pollution, which includes ozone, particulate matter, and other smog-forming emissions.The health risks of air pollution are extremely serious. Poor air quality increases respiratory ailments like asthma and bronchitis, heightens the risk of life-threatening conditions like cancer, and burdens our health care system with substantial medical costs. Particulate matter is singlehandedly responsible for up to 30,000 premature deaths each year.
|
Smog formation from vehicle emissions and other sources |
Passenger vehicles are a major pollution contributor, .... READ FULL ARTICLE
Archplan Inc. Philipsen Architects