Climate Change Science - The Effects of Rising Temperatures on Human Health

Australia: The Land Where Time Began

Climate Change Science - The Effects of Rising Temperatures on Human Health

Human health is already being affected adversely by global warming, and climate change poses a serious threat to the health of humans. It is estimated by the WHO (World Health Organisation) that 1 million people have been killed by global warming, directly or indirectly, since the year 2000. Another 800,000 people are killed every year by air pollution, and this number is expected to rise with the increasing temperatures.

The seasons are changing, especially in the mid-latitudes, with spring coming earlier and autumn coming later nearly every year. As a result of this change the growing season is lengthening for plants, which increases the pollen count in the atmosphere, which causes allergic reactions in humans. Respiratory infections and death, especially in the very young and the very old, can often result from allergic reactions.

Food and water borne diseases are becoming an increasing problem for human health as temperature continues its upward trend, and the following forecast is not good for these reasons:

It is predicted by the U.S. Centres for Disease Control (CDC), that food borne diseases cause about 76 million cases of illness, of which 325,000 are hospitalised, with 5,000 dying in the U.S. every year. Also in the U.S., water borne diseases cause about 9 million cases of illness every year.

There are a number of diseases that can be transmitted by contamination of water and food, such as E. coli, typhoid, hepatitis A, dysentery, cryptosporidiosis, polio, giardia, cholera, and botulism.

It is difficult to remove many of these disease causing organisms from drinking water at water treatment facilities, some of these being cryptosporidiosis and giardia. There was an outbreak in Madison, Wisconsin in 1993 that made 403,000 people ill after drinking tap water. It has been estimated that the outbreak cost a total of $96.2 million, comprised of $31.7 million for medical costs, and losses of productivity of $64.6 million.

The second leading cause of death among young children is diarrhoea that is caused mainly by food and waterborne diseases. It is estimated by the CDC that every year there are 4 billion cases of diarrhoea of which 2 million die.

How the incidence of food and waterborne diseases can be increased by climate change.

The occurrence/survival of bacteria, toxic algae, and other contaminants of food and drinking water is increased by increasing temperatures. The IPCC has pointed out that the amount of high quality drinking water is already being reduced by climate change, and as the temperature continues to rise the situation can only get worse, which will result in the incidence of disease continuing to rise and people are forced to rely on poorer quality water resources.

The major pathogens responsible for acute gastroenteritis reproduce faster in warmer conditions. Based on a study of the impacts on the U.S. lakes of climate change, it is predicted that there will be an increase in the incidence of recreational waterborne disease outbreaks.

More extreme flooding and storms are predicted to result from climate change, and these are known to lead to contaminated water supplies. Sewer and stormwater systems can be caused to overflow by heavy rainfall, and this overflow can release untreated (raw) sewage into local water sources.

It has been reported by WHO that in 2000 approximately 2.4 % of diarrhoea cases worldwide were associated with climate change. It is predicted that in 2030, if nothing changes, there will be up to 10% increased risk of diarrhoea in some areas, resulting from warmer temperatures, more severe rainfall and flooding.

It is also expected by the IPCC that the distribution and activity of flies, cockroaches and rodents could respond to climate change by changing. These species are considered to be carriers of foodborne pathogens and therefore major hygienic pests in the domestic environment.

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