Environmental pollution and Global Issues

Air pollution is a major global environmental risk to our health and food security. It is estimated to cause about 3.7 million premature deaths worldwide and destroys enough crops to feed millions of people every year.

Health officials, the general public and farmers need advance notice when dangerous air quality levels are on the rise. Researchers and engineers at the National Center for Atmospheric Research (NCAR), in collaboration with other agencies, are dedicated to developing new technologies that directly help decision-makers plan for high-pollution days.

This work allows meteorologists and local planners to:

• Forecast air quality for cities and rural areas days in advance.
• Project impact of future changes in human activities and climate on air quality.
• Quantify cross-border transport of air pollution.
• Quantify regional transport of air pollutants within a country.
• Assess societal impacts of air pollution.
• Improve emission estimates.

Air pollution is a global problem

An Advanced Air-Quality Forecasting System

Current air-quality forecasts are limited. They provide a simple single-value prediction and do not specify the uncertainty associated with the prediction. They also simplistically tell whether ozone levels will be high or low. Much more detail in the forecast is needed, and, with funding from NASA, NCAR and its partners are developing a new capability to produce 48-hour detailed forecasts of ground level ozone and fine particulate matter.

This new forecasting capability combines satellite and in situ observations with state-of-the-art modeling and will generate air quality forecasts in fine detail. Just as a weather forecast, for example, might warn of an 80% chance of rain in the afternoon, new air quality forecasts might warn of an 80% chance of high ozone levels during certain times of the day. Such improved forecasts will significantly enhance the decision-making activity in air quality management. This system is being set up over the USA but can be easily applied to any part of the world.

Projection of Future Air Quality

Fine particulate matter predictions over the US.

To quantify future changes in air quality due to changes in future climate and human activities, NCAR has developed a global and regional climate model coupled with chemistry. These models can be used to examine the impact of different emission scenarios on the air quality of any region of the world. They have been used to predict changes in air quality over the USA and India as far out as mid-century (2050).

The model results show that Representative Concentration Pathway (RCP) 8.5 anthropogenic emission scenario can improve the air quality in the USA but not in India.

Quantifying Cross-Border Transport of Pollutants

Maximum daily average 8-hour surface ozone over South Asia for the present day (1995-2004, left) and future (2045-2054, right) RCP 8.5 scenarios.