How easy it is to take things for granted. From the comfort of the developed world it is hard to imagine what it must be like to be constantly hungry, with an ever-present fear of starvation and to live in a world where a plentiful supply of fresh water is just a dream.

Nobody knows the exact number of malnourished people in the world. Latest estimates by the UN Food and Agriculture Organisation (FAO), released in October 2010, put the number at 925 million, which is 13.6% of the estimated world population. Other sources maintain that by 2007 there were already a billion malnourished people in the world and the number has been rising by 10 million a year ever since. Whatever source you care to rely on for information, these are mind boggling numbers. In round figures at least 1 in 7 people are hungry.

As long ago as 1996 the World Food Summit said that food security would only exist ''when all people at all times have access to sufficient, safe, nutritious food to maintain a healthy and active life.'' Taking 824 million as the starting point, which was the number in 1990-92, a target was set to halve this number of undernourished people by 2015. Although there has been progress in Asia, Latin America and the Caribbean, it is clear that the world is not making much overall progress towards this goal.

Understandably, nearly all of the undernourished people come from developing countries, with 62% coming from Asia and the Pacific Region and 26% coming from Sub-Saharan Africa. Somewhat surprisingly according to FAO 19 million malnourished people live in developed countries.

Children are the most vulnerable and poor nutrition plays a part in at least half of the 10.9 million child deaths each year. Children born to a malnourished mother have a higher proportion of learning disabilities, mental problems, general poor health, blindness and premature death.

Poverty is the underlying cause of hunger and the political situation in a given area can also be an important factor. In many cases the resources and income of an area are based on military, political and economic power. Typically this will end up in the hands of a minority who live well, while those at the bottom barely survive.

Clearly there must be political will to improve the local situation, but often the question is ''where on earth do we start?'' In countries that are already desperately poor, it is necessary to prioritise scarce resources. Unfortunately it often boils down to who can shout the loudest.

Charities can make a significant contribution, but it is important if possible to avoid 'food aid' projects where food is simply handed out. This in effect is no more than ''dumping' food and will simply undermine the local economy by undercutting local producers, who will then stop producing.

Sometimes in the case of extreme famine, immediate support is necessary and food aid is the only answer, but initiatives to support local producers by providing tools, seeds and expertise have proved to be significantly more successful in the longer term. Often a combination of both is an appropriate solution.

Poverty and political turmoil are the usual reasons for hungry people to stay hungry, but it is important to look at the reasons why they are hungry in the first place. Almost invariably the answer will

point to climatic conditions.

Many of the poorer people of the world live by subsistence farming and their crops are dependent on the weather. Extreme weather can prove fatal. Crops can fail if the weather is too hot or too cold; or too dry or too wet, or simply because rain does not fall at the right time.

The Intergovernmental Panel on Climate Change believes that: ''climate change alone is estimated to increase the number of people at risk of hunger to between 40 million and 170 million.'' It is considered to be very likely that climate change and variability will lead to extreme weather events such as more intense and longer droughts. This coupled with water scarcity reduces dietary diversity and overall food consumption, which in turn can lead to under nutrition.

The frequency of rainfall has increased over most land areas and the risk of flooding may increase, both from sea level rise and increased rainfall in coastal areas. As a result it is likely that more people will become exposed to diarrhoeal and other infectious diseases, which will lower their capacity to utilise their food effectively.

The projection is that by 2020 climate change will increase the burden of diarrhoeal diseases in low income regions by 2% to 5%. In Africa it is estimated that by 2100 climate change will have increased the number of person-months of exposure to malaria by 16% to 28%. This will affect food availability, access an utilisation and contribute to increased rates of anaemia in pregnancy.

Changes in vegetation on a large scale will affect surface temperatures and alter regional rainfall patterns. Diminishing and melting mountain glaciers could lead to water shortages and further food insecurity. It has been estimated that a 2^°C rise in world temperature would lead to 220 million people being put at risk of under nutrition due to reduced agricultural output.

Water security in many ways goes hand in hand with food security At present, almost 900 million people worldwide do not have access to clean water and more than 2.6 billion people do not have access to basic sanitation. Studies indicate that around 1.5 million children under the age of five die each year as a result of water and sanitation-related diseases.

Image: Tap Water.

In October 2010 the UN Human Rights Council affirmed that the right to safe, clean drinking water and sanitation is contained in existing human rights treaties and that States have a primary responsibility to ensure the full realisation of this and all other basic human rights. This is legally binding.

Food and water security are complex sustainable development issues, linked to heath through malnutrition, but also to sustainable economic development environment and trade.

We live in a world of extremes. Many of us have so much food that the World Health Organisation estimates that more than 1.5 billion adults, aged 20 and older, are overweight. Of these over 200 million men and nearly 300 million women are obese. Yet at the same time, in other parts of the world, millions are starving.

Food and water security are an aspiration for all and their absence is an affront to human dignity. Regrettably it must be said that universal food and water security are still a long way off but this should not stop everyone from doing everything in their power to bring it closer.

A major contributor to this lack of security is obviously climate change and although it is impossible to halt its relentless progress, by becoming more environmentally aware at least we can help to slow it down. From the comfort of the developed world it is easy to forget that we have a global responsibility for all mankind.