Over the past 50 years, human activities, especially the burning of fossil fuels, have accumulated carbon dioxide and other greenhouse gases in the lower atmosphere in sufficient quantities to retain excess heat and affect the global climate.
Over the past 130 years, the world temperature has increased by about 0.85°C. over the past 25 years, the rate of global warming has accelerated, exceeding 0.18°C per decade.
Sea levels are rising, glaciers are melting and rainfall patterns are changing. Extreme weather events are becoming more intense and frequent.
What is the impact of climate change on health?
Despite the fact that global warming may bring some local benefits, such as reducing the number of deaths in places with a temperate climate and the growth of food production in certain areas, the overall impact of climate change on health, apparently, will be the vast majority of cases negative. Climate change affects social and environmental health factors — clean air, safe drinking water, sufficient food and safe shelter.
Extremely high temperatures directly result in death from cardiovascular and respiratory diseases, especially among the elderly. For example, during the heat wave in summer 2003, more than 70,000 additional deaths were recorded in Europe.
In addition, high temperatures in the air raise levels of ozone and other pollutants, exacerbating cardiovascular and respiratory diseases.
In addition, levels of pollen from plants and other air allergens increase during extreme heat. They can cause asthma, which affects about 300 million people. It is expected that the continued increase in temperature will increase the burden.
Natural disasters and changing rainfall patterns
Worldwide, the number of weather-related disasters recorded has more than tripled since the 1960s. Every year, these disasters result in over 60 000 deaths, mainly in developing countries.
Rising sea levels and increasingly extreme weather events will destroy homes, health facilities and other basic services. More than half of the world’s population lives within 60 km of the sea. It can happen that people will be forced to leave their places, which in turn will increase the risk of a variety of health consequences — from mental disorders to infectious diseases.
The increasingly changing nature of precipitation patterns is likely to have an impact on freshwater resources. Lack of safe water can jeopardize hygiene and increase the risk of diarrhoeal diseases, which kill nearly 760,000 children under 5 years of age each year. In extreme cases, water scarcity leads to drought and famine. By the end of the 21st century, climate change could lead to an increase in the number and intensity of drought events at the regional and global levels..
The frequency and intensity of floods are also increasing, and the frequency and intensity of extreme precipitation will also increase during this century.  due to flooding of pollution of freshwater supplies, increasing the risk of diseases transmitted through water, and produce spots favorable for breeding of insect disease vectors such as mosquitoes. Floods also lead to drowning and physical injuries, destruction of homes and disruption of health services.
Rising temperatures and changing rainfall patterns are likely to reduce basic food production in many of the poorest regions to 50% by 2020 in some African countries. This will increase the prevalence of malnutrition and malnutrition, which currently kill 3.1 million people each year.
Climatic conditions have a strong impact on water-borne diseases and diseases transmitted by insects, molluscs and other cold-blooded animals.
Climate change is likely to prolong transmission seasons of vector-borne diseases and alter their geographical areas. For example, climate change in China is projected to significantly expand the area where cases of schistosomiasis-a disease transmitted by mollusks — occur.
The climate has a strong impact on malaria. Malaria transmitted by Anopheles mosquitoes kills almost 600,000 people a year, mostly African children under 5 years of age. Aedes mosquitoes, which carry dengue, are also highly sensitive to climatic conditions. Studies suggest that climate change will also increase the risk of dengue infection.
Health impact assessment
The assessment of the health effects of climate change can only be very approximate. However, the who estimated, taking into account only the range of possible health effects, and based on assumptions about continued economic growth and progress in the field of health, it was concluded that climate change is expected to cause approximately 250 000 additional deaths per year between 2030 and 2050, 38,000 people die due to the impact of heat on elderly 48,000 to diarrhoea, 60 000 — from malaria, and 95 000 — due to child malnutrition..
Who is at risk?
Climate change will affect all groups, but some groups are more vulnerable than others. People living in small developing island States and other coastal areas, megacities, and mountainous and polar regions are particularly vulnerable.
Children, especially in poor countries, are among the most vulnerable to the health risks associated with climate change. They will be exposed to longer-term health effects. More severe health effects are also expected for older persons and people who are already ill or ill.
Areas with weak health infrastructure, mainly in developing countries, will be less able to prepare for and respond to climate change without external assistance.
The activities of WHO
Many policies and preferences of individuals have the potential to reduce greenhouse gas emissions while providing significant health benefits. For example, safe use of public transport and active movement — such as Cycling and walking as alternatives to using private cars, can reduce carbon emissions and to reduce the burden of household air pollution which causes 4.3 million deaths per year, and air pollution in the environment, which causes about 3.7 million deaths every year.
In 2015, the world health Assembly approved a new who work plan on climate change and health. It includes:
- Partnerships: coordinate with partner agencies within the UN system and ensure that health issues are appropriately placed on the climate change agenda.
- Awareness-raising: provide and disseminate information on the health threats posed by climate change and on opportunities to improve health by reducing carbon emissions.
- Scientific and evidence: coordinate reviews of scientific data on the links between climate change and health and develop a global research agenda.
- To support the adoption of retaliatory measures in the field of public health in connection with climate change: helping countries to build capacity to reduce health vulnerability in connection with climate change and improve health by reducing carbon emissions.