Their carbon dioxide (CO2) emissions have increased by 30 percent since 2000, according to a report published on Thursday.

In the document, the head of UNEP’s Sustainable Mobility Unit, Rob de Jong, emphasized the need to implement ambitious regulations to curb emissions that are harmful to the environment and human health.

According to the study, heavy-duty vehicles are responsible for more than 40 percent of nitrogen oxide emissions on the roads, as well as 60 percent of PM2.5 particulate matter and 20 percent of black carbon, both of which are associated with heart and lung problems.

The situation is aggravated in developing countries that depend on imports of used heavy-duty vehicles, often in precarious and polluting conditions.

The text also warned that the increase in exports of such used equipment from industrialized economies to developing nations contributes to increased pollution in the southern nations.

Although heavy vehicle exports represent a modest 3.6 percent of the total value of world trade in automobiles, their associated CO2 emissions have increased by more than 30 percent since 2000, with trucks contributing 80 percent of that increase.

CO2 is the main greenhouse gas, the consequence of which is global warming that accelerates climate change.

The UNEP report, along with the Climate and Clean Air Coalition, provides the UN’s first global overview of the scale and regulation of used heavy vehicles.

On their contribution to global air pollution, traffic accidents, fuel consumption and climate emissions, the research recommends ways to reduce the harmful aspects, for people’s health and the climate.

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