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The World Health Organization commemorates its foundation as World Health Day on 7th April. Every year on this day, WHO highlights certain issues which are of major importance to global health. The year 2008 is the 60th anniversary of WHO. The theme of this year is – “protecting health from climate change”. The theme is very relevant and the timing very appropriate, which rightly puts the health at the centre of the worldwide dialogue on this urgent issue and recognises that climate change poses the maximum threat to global public health.

Throughout most of the human history, all climate changes were the direct results of natural forces. This has changed with the industrial revolution, when new industrial and agricultural practices began to alter the global climate. It is the most important cause of worry in our world today, as it has far reaching consequences on every aspects of life. The fourth assessment report (AR4) 1 of the Inter-governmental Panel on Climate Change (IPCC, which shared the Nobel Peace Prize of the year 2007) states that global warming is now unstoppable 2 and human activities are to blame for the heat-trapping greenhouse gases that have caused global temperature to rise dramatically since 1950. Main cause is significant elevation of atmospheric carbon dioxide as major greenhouse gas, due to widespread use of the fossil fuels in thermal power plants, industries and transport vehicles. Deforestation, land-use changes, chemical agriculture and population growth also make a contribution. Today, global warming is progressing at an alarming pace, becoming too dangerous for the life on this planet. This climate change is looming as the biggest human catastrophe, threatening our ultimate survival.

Global warming unleashes an unprecedented and widespread health hazards. As per WHO, global warming currently contributes to more than 1.5 lakh deaths and 50 lakh illnesses every year 3. 50 million environmental refugees, displaced by floods, droughts and rising sea levels, are expected by 2010. Numbers may double by 2030. Experts apprehend that global warming will kill billions in this century!
Climate change can affect our health directly and indirectly. Scorching heat and heat waves are the direct results of this climate change. Heat related diseases, like heat strokes, will increase sharply. In August 2003, heat waves claimed as many as 35,000 lives in Europe. The sick and the elderly persons are most vulnerable, for their decreased ability of cooling the body. People in temperate countries, who are not accustomed to hot weather and people in countries where houses and other infrastructures are not designed to cope with hot climate, are more vulnerable. Technological adaptations, e.g. installation of air-conditioners and construction of heat-minimising houses will happen quickly among the rich. So, heat waves will affect the poor more than the rich. Overall, climate change has disproportionately more effect on the under-developed countries and on the poorer segments of the society.

More than 65% of world population are at increased risk of infection 4, as breeding of mosquitoes and spread of many infections are enhanced in hot climate. There will be a massive spread of the whole range of mosquito-borne diseases like malaria, dengue, chikungunya, encephalitis and yellow fever. In successive two years of 2005 and 2006, dengue and chikungunya became pandemic. Malaria and encephalitis have become endemic in many countries. Malaria is moving to higher altitudes also. Tick and other insect-borne diseases, e.g. lyme disease, west nile fever and rocky mountain spotted fever are spreading to areas once considered too cold for them to survive. Besides this redistribution and re-emergence of several diseases, many new infections have come-up in last 25 years, e.g. SARS, Bird-flu, Nipah virus, Ebola virus, Arena virus, Hantavirus, new strains of E.coli and V.cholerae. Under changing environment, agents are also changing, resulting in a new spectrum of diseases for the human-hosts.

Climate change vigorously affects our health by many indirect ways. Hot climate increases the evaporation of ocean water, resulting in heavy rainfall and flood in many areas. As a result of flood there will be contaminated water supplies and breakdown in sewerage and garbage services, leading to spread of the whole range of water borne and food borne diseases, along with other infections. Cholera thrives in such situation. Severe and prolonged droughts are becoming more common, particularly in regions of sub-Saharan Africa. There will be a sharp increase in malnutrition caused by starvation, as a result of the poor agricultural yield due to droughts. By 2020, rain-fed agricultural yield in some African countries may be reduced by 50 %. Water is already in short supply in different parts of the world. Under hot climate conditions, there will be severe water scarcity 5, with great implications on health. By 2020, 75– 250 million people in Africa will be exposed to water scarcity due to climate change. Increasing air pollution from the continued burning of fossil fuels and release of large quantities of particulate matters will cause higher rates of respiratory and cardiovascular diseases. The concentration of photo-chemical pollutants, like ozone, increases with increasing temperature. Increased ground-level ozone damages lung tissue, induces and increases asthma. Depletion of stratospheric ozone allows more and more UV-rays to enter into the atmosphere and thus increases the incidence of malignancies.

Melting of glaciers and polar ice will increase the quantity of ocean water. Along with that, thermal expansion of the ocean water will cause about 18 – 59 cm rise of the sea level by 2100. With increasing sea level, there will be coastal erosion, contamination of freshwater supply and degradation of agricultural areas resulting in a massive impact on our eco-system, health and life. There will be a 50 fold rise of the number of people exposed to coastal flooding per year in 2080. It may be quite disastrous for the people of low-lying areas like Maldives, Sunderban and Kolkata. 13 of the 20 largest cities on earth are located at sea level on coasts 5. As sea level rises, there go our medical institutions, water treatment plants, emergency response units such as fire departments and ambulances. The bulk of the services designed to keep us healthy are almost all located in our larger cities, which are also located frequently at sea level. Fiercer storms will occur as hurricane formation requires warm ocean surface along with hot climate. In fact, last 10 years has been the most active hurricane season in the history. There will be a sharp change in the pattern of natural disasters, like – stronger tropical storms and cyclones, higher category of hurricanes, flooding in certain areas and droughts in others, forest-fire, earthquakes and volcanoes. This will result in massive displacement of humans from their natural habitat. All these will have an adverse effect on our psychological health too. Hospitals, health services, ambulances, fire-services, electricity, food and water supply, transport and all sorts of communications become ineffective altogether after the disaster, with a massive impact on health and life.

No country will escape these hazards. Ironically, the poor nations least responsible for greenhouse gases are worst affected by climate change. Though it affects everyone on earth, poor people are most vulnerable to the disease and death, as they are least able to cope. Here lies the major ethical challenge.

It is our duty as health providers and as responsible members of the society, to be conscious about the magnitude of this problem and to control this menace. Traditional health tools like immunization, sanitation, disease surveillance, vector control and preparedness to deal with disasters will help decrease the ill effects of climate change. It is high time that we listen to our conscience and decrease our ‘carbon-footprints’. At the same time, we should be adequately knowledgeable, equipped and prepared to deal with the emergencies and the long term effects arising out of this climate change.

Obviously it is impossible to protect our health or ourselves if the climate change goes on steadily. We should better give our honest and best efforts right now to “prevent climate change to protect our health”. So, all sensible global citizens, particularly all the doctors should raise their voice today

to stop burning of fossil fuels, as it is the real driver of the climate change
to call for clean and renewable energy source. Widespread use of nuclear energy may be the only key to our future survival 6.
to draw attention of our policy makers to this very important issue and
to create awareness among the people about this ensuing real threat to our ultimate survival
Energy source is fundamental for the environment of our health and for the health of our environment. Without that, we are going to have a very polluted, sick and disastrous future.
We must, must act now to save our Earth Planet, our civilisation and our next generation.

For more information, read our April issue.