WASHINGTON - Left unchecked, climate change could increase breathing problems and health costs by exacerbating ground-level ozone, warns a report Thursday by the Union of Concerned Scientists.
Higher ozone levels could trigger 2.8 million additional serious respiratory illnesses and 944,000 extra missed school days in the United States in 2020 that could cost $5.4 billion, according to the peer-reviewed report by the Cambridge, Mass.-based environmental group.
"Even a small increase in ozone due to a warmer climate would have a significant impact on public health," said report co-author and UCS public health expert Liz Perera in announcing the findings. "It would mean more asthma attacks, respiratory illnesses, emergency room trips and premature deaths."
The most vulnerable U.S. states? The study used a mapping model by the Environmental Protection Agency to calculate national impacts and rank the 10 states most likely to be harmed in 2020.
In terms of costs, the research found that California would be hit hardest, followed by Texas, New York, Pennsylvania, Illinois, Ohio, Michigan, North Carolina, New Jersey and Virginia. It said these states have large numbers of urban residents, children and seniors as well as high levels of nitrogen oxides and VOC (volatile organic compound) emissions from vehicles and power plants.
Ground-level ozone, smog's primary component, is generated by the chemical reactions between nitrogen oxides and VOCs that come from heat and sunlight. Warmer average temperatures from a changing climate may boost ozone concentrations and stagnant air that can cause ozone pollution to settle over an area for a long time.
The study says EPA's Clean Air Act has reduced ozone-forming pollutants, but many counties and states are still unable to meet the federal ozone standard. EPA is expected soon to strengthen this standard, which is increasingly important since average U.S. temperatures have risen more than 2º Fahrenheit in the past century.
If global warming emissions continue to increase, the study estimates that average U.S. temperatures could rise 3º to 5.5º F by 2050 and result in about 11.8 million additional serious respiratory illnesses, 29,600 more infant and senior hospitalizations and 4.1 million additional lost school days in 2050. Yet it says these health impacts could be cut about 70% if emissions decline and temperatures rise 2º to 4º F instead.
"The good news is we can address both ozone pollution and climate change by cutting fossil fuel emissions," Todd Sanford, a UCS climate scientist and report co-author, said in a statement.