Last year was the hottest year since we began keeping track of temperatures in 1880. A joint report from the National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA) confirmed the record, adding that 2014 was the 38th consecutive year in which temperatures were warmer than the past year and 9 of the 10 warmest years to date were after 2000.
According to the Intergovernmental Panel on Climate Change (IPCC), the atmosphere and ocean temperatures have warmed, snow and ice levels have fallen, sea level has risen, “and since the 1950s, many of the observed changes are unprecedented over decades to millennia.” Ocean and land temperatures have risen an average of 0.85°C between 1880 and 2012. Most of the planet is experiencing a decrease in the number of cold days and an increase in the number of warm days. A WHO report estimates that an excess 250,000 yearly deaths will be attributable to climate change between 2030 and 2050. These deaths are predicted to result from malnutrition, malaria, diarrhea, and heat stress.
The leading cause of severe weather fatalities in the United States is extreme heat. A study of 23.7 million Medicare enrollees found that older adults are more likely to be hospitalized during heat waves for diseases including fluid and electrolyte disorders, kidney failure, urinary tract infections, heat stroke, and septicemia. The increased risk can last up to five days after the heat wave; however, absolute numbers of excess hospitalizations were small (about 1.2 per 100,000 at risk for the diseases.) Nonetheless, this could increase as heat waves become more common.
Another study concluded that climate change is directly linked to respiratory disorders and infectious diseases. Heat increases the airborne level of pollen and allergens as well as ozone and pollutants that can exacerbate asthma and cardiovascular disease. Indoor and outdoor air pollution already kill 7 million people a year at current levels. The researchers predict that by 2050, New York City and Milwaukee may have three times the current number of days hotter than 90°F.
Climate changes have seemingly resulted in more extreme weather. Rates of natural disasters have tripled since the 1960s. Natural disasters affect environmental determinants of health including water, food, and shelter. Floods and storms can contaminate drinking water, destroy land used for agriculture, and affect infrastructure. More than half of the world population lives within 40 miles of the sea, and rising sea levels may render entire cities obsolete. Increasingly variable rainfall patterns will also affect water supply and agricultural yields, especially in poorer places where there is little infrastructure.
Rising temperatures and changing rainfall patterns are expanding the range of mosquitos and snails, which are vectors for diseases like malaria and schistosomiasis. Mosquitos carrying dengue fever are expected to expose an additional 2 billion people to the disease by the 2080s. Both Chikungunya and West Nile Virus are expected to increase in prevalence as the mosquitos carrying these viruses spread to new areas.
On September 23, the United Nations held the 2014 Climate Summit in New York City. Several leading scientists and policymakers were present to speak on a number of issues ranging from the health impacts of climate changes to examples of pollution reduction and clean industries. Dr. Richard Horton, editor of the British medical journal The Lancet, explained the upside of climate change.
The climate crisis is not all bad news – there is a climate dividend to be grasped. There are opportunities for wellbeing and jobs…Part of the challenge is to communicate the threats that climate change presents to health. These are well known, including changes in patterns of disease and mortality, to nutrition, and water and sanitation, and population migration…But it is better to emphasize the opportunities. Changes to diet, electricity generation, transportation, will bring benefits to our wellbeing. We need concrete actions to turn this opportunity into a reality.
– Dr. Richard Horton
It is difficult to predict the actual impact of climate change on public health in terms of numbers and costs, but we have already seen public health concerns directly linked to climate. Efforts are underway to enact policy aimed at reducing emissions and preparing for climate change, but the long-term changes remain to be seen.