1 The impacts of climate change

1.1 How we are affected by climate change

Climate change is something that is affecting us, regardless of where we live. Most people understand the general concept of what climate change is, but many do not know what the long-term consequences are.

Climate change affects ecological systems, and changes in ecological systems influence the processes of disease transmission. Rising temperature and other changes in temperature and precipitation, as well as extreme climate events such as floods or droughts, are capable of changing ecological systems. An increase of just a few degrees in average temperature can cause dramatic changes in conditions that are important to the quality of life – and ultimately the Earth's ability to support life.

We may not always see or feel the effect of climate change directly, but it affects us all. For one person it might mean paying more for food because flooding or drought has damaged crops in the area where they live. For another it might mean a higher risk of contracting a disease like malaria, which spreads more easily in warm, wet climates, such as can be found in many African and South American countries. Someone else might face losing their home or even life in a catastrophic weather disaster made worse by global warming.

In one way or another we are all vulnerable to the effects of weather-related disasters, but people in the poorer countries of the world face a far greater threat due to risk factors that include inadequate housing located on flood plains and steep hillsides, weak healthcare systems and heavy economic dependence on agriculture. In the last 20 years, it is not uncommon for single weather events, such as tropical cyclones, hurricanes and floods, to kill thousands of people in regions such as South Asia, southern China, and Central America. If the warming continues for years, extreme weather events and sea level rise will require a great many people to become climate refugees because their homes will be under water.

These Web-based resources provide more background information:

• The UK Climate Impacts Programme has published information on the impacts of climate change on the UK. See the simple table starting at page 18.

• How does climate change affect us?

• The Red Cross Red Crescent Climate Guide, dated 2007, shows clearly how climate change will impact on poor and vulnerable countries.

• Earth Under Fire: How Global Warming is Changing the World is a comprehensive look at the world wide effects of climate change, in dramatic photographs, maps and quotes from world climate science leaders.