Maritime emissions refer to the pollution generated by ships and other vessels as they traverse the world’s oceans and waterways. These emissions can come in the form of air pollutants like nitrogen oxides (NOx), sulfur oxides (SOx), and particulate matter (PM), as well as greenhouse gases like carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).

Maritime emissions are a significant contributor to global air pollution and climate change, accounting for around 3% of global greenhouse gas emissions. However, this figure is expected to rise as global trade and shipping volumes increase.

There are several ways to reduce maritime emissions, including the use of cleaner fuels like liquefied natural gas (LNG) and biofuels, the installation of emission reduction technologies like scrubbers and particulate filters, and the adoption of more efficient vessel designs and operating practices.

International organizations like the International Maritime Organization (IMO) have established regulations and guidelines aimed at reducing maritime emissions, such as the IMO’s MARPOL convention which sets limits on sulfur and nitrogen oxide emissions from ships. However, more action is needed to address this pressing issue and to ensure that the world’s oceans remain healthy and sustainable for future generations.

The United States Environmental Protection Agency (EPA) is responsible for measuring and regulating emissions from a wide range of sources, including the maritime sector. To measure maritime emissions, the EPA has established several programs and initiatives that focus on monitoring and reducing air pollution from ships and other vessels.

One such program is the National Clean Diesel Campaign, which seeks to reduce emissions from diesel engines in various sectors, including the maritime industry. Through this program, the EPA provides grants and technical assistance to help ship owners and operators retrofit their engines with cleaner technologies like exhaust gas scrubbers and diesel particulate filters.

In addition to the National Clean Diesel Campaign, the EPA also participates in the North American Emissions Control Area (ECA), a joint initiative between the United States, Canada, and Mexico to reduce emissions from ships in North American waters. The ECA sets limits on the amount of sulfur that can be present in marine fuels and requires vessels to use cleaner fuels or emissions control technologies.

Furthermore, the EPA also uses a variety of measurement techniques to track and monitor maritime emissions, including the use of remote sensing devices and emissions monitoring systems that can measure the emissions of individual vessels as they pass through certain areas.

Overall, the EPA is taking a proactive approach to measuring and reducing maritime emissions in the United States, working closely with industry stakeholders and other government agencies to ensure that the maritime sector plays its part in mitigating the effects of air pollution and climate change.